MXPA06005792A - Developments in biologically active methylene blue derivatives (2) - Google Patents

Abstract

A phenothiazinium compound of Formula (I) for use as an antimicrobial agent for the prevention of microbial infections wherein:Rl, R2, R3 and R4 each independently is an optionally substituted linear, branched or cyclic hydrocarbon group;or Rl and R2 or R3 and R4 together with the N atom to which they are attached form an optionally substituted 5-, 6- or 7- membered ring;XP- is a counteranion;and P is 1, 2 or 3. The invention also relates to compositions comprising phenothiazinium. compounds, to selected compounds and their use as medicaments, as PDT agents, as photodiagnostic agents, to a conjugate or composite formed between a phenothiazinium. and a polymer;and to a method for sterilising fluids in which the fluid is passed over the conjugate or composite whilst it is illuminated. The compounds are biologically active photosensitisers which are strongly photocytotoxic and have application in the areas of photodynamic therapy (PDT), as well as for the diagnosis and detection of medical conditions and related uses in photochemical internalisation, in the production of cancer vaccines, in the treatment and prevention of microbial infections and in photodisinfection or photosterilisation.

Description

DEVELOPMENT IN BIOLOGICALLY ACTIVE METHYLENE BLUE DERIVATIVES (2) FIELD OF THE INVENTION This invention relates to biologically active photosensitizers that are strongly photocytotoxic and have application in areas of photodynamic therapy (PDT), their compositions, their uses as medicaments particularly in the treatment of cancer and in the treatment and prevention of microbial infections. , its uses in diagnosis and detection of medical conditions and related uses in photochemical infernalisation, in the production of vaccines against cancer and in photo-disinfection or photo-sterilization. The invention also relates to conjugates and mixed substances of photosensitizers that can be used in photo-disinfection or photosterilization. BACKGROUND OF THE INVENTION It is known that certain organic compounds ("photosensitizers") can induce cell death by absorbing light in the presence of oxygen. The cytotoxic effect involves type I and / or type II photooxidation. These photosensitizers find use in the treatment of cancer and other diseases or infections with light (photodynamic therapy) and in the sterilization (which includes disinfection) of surfaces and fluids by means of the destruction Ref.169942 induced by light of microbes. In this context, the term "sterilization" means the reduction or elimination of microbes in a particular situation. It is also known that certain colored phenothiazinium compounds (e.g., methylene blue) may occur in the processes of type I and type II photooxidation, but compounds of this type have so far proved inadequate or of low efficacy as sensitizers for photodynamic therapy, or have shown low photochemical antimicrobial activity, or have potential problems in use because they are positive Ames. For PDT application, a good sensitizer must have some and preferably all of the following properties: • It must cause the destruction of target cells (eg tumor cells or bacterial cells) efficiently exposed to light (preferably at wavelengths of approximately 600-800 nm) • Must show a high degree of selectivity between target and normal tissues • Must have relatively low toxicity in the darkness • It should cause little or no photosensitivity to the patient's skin • It should have short-term drug intervals for patient and hospital convenience and minimize treatment costs • Must be suitable for use in vivo, in particular must not be mutagenic • For applications in photo sterilization, a good sensitizer should show a strong phototoxic effect on a wide range of microorganisms, ideally when using ambient light, and should not easily photobleach. In oncology, various types of photosensitizers have been used to treat both solid and thin tumors of hollow organs such as the esophagus and bladder. However, the use of these photosensitizers has been partially restricted due to the lack of selectivity between the tumor and the healthy tissue and partially due to the prolonged photosensitivity to the skin that may be caused. There is a need for new photosensitizers that cause little or no photosensitivity of the skin and that selectively destroy the tumor cells. Although PDT has been used previously in the treatment of tumors, it has not yet been used clinically against infections caused by bacteria and other microorganisms. The use of antibiotics has become challenging due to the increasing resistance of many bacterial species to commonly used antibiotics, such as tetracyclines and beta-lactams. Infections resistant to antibiotics acquired in hospitals such as MRSA are especially problematic. Antibacterial photodynamic treatment is a compromising alternative to antibiotics for local treatment. When antibacterial agents are developed, an important problem that must be overcome is the absorption of the drug in the bacterial cell. Gram-negative and gram-positive bacteria differ in the composition of their outer surface and respond differently to antimicrobial agents, especially in terms of absorption. Due to the high negatively charged surface of gram negative bacteria, they are relatively impervious to neutral or anionic drugs, which includes most of the photosensitizers used. The development of antimicrobial photosensitizers that are effective against gram-negative bacteria as well as gram-positive bacteria should be highly beneficial in replacing antibiotics with commonly used drugs that become increasingly infectious due to resistance. A number of different types of photosensitizer have been investigated in bacteria. These include phenothiazinium compounds, phthalocyanines, chlorines and photosensitizers that occur naturally. To be absorbed in gram negative bacteria, it is accepted that the cationic derivatives are the most effective.

The phenothiazinium compounds are blue dyes with maximum absorption at wavelengths between 600-700 nm. They have been studied for their non-photodynamic antibacterial properties but a few in addition to methylene blue and toluidine blue have been investigated photodynamically. Ainwright et al (1998) investigated the effect of a series of phenothiazinium methylene blue derivatives on tumor cell lines and bacteria. A new methylene blue (NMB) and dimethylmethylene blue (DMMB) were effective in inactivating MRSA and were shown to be more effective photosensitizers than methylene blue when acting on pigmented melanoma cell lines. Wagner et al (1998) studied these dyes and also a hydrophobic derivative for the inactivation of enveloped viruses. The precise mode of antibacterial action of methylene blue is unknown, but the hypothesis is that due to its stereochemistry it must be interspersed in DNA, and that photodynamic action causes DNA damage. It has been shown that methylene blue is ineffective as an antitumor agent. In addition, it is known that methylene blue is susceptible to photobleaching, which could be a serious drawback in some applications. Due to the recognized limitations of methylene blue both tumor PDT and antimicrobial PDT would benefit from the development of new photosensitizers based on phenothiazinium. The PCT application PCT / GB02 / 02278 discloses certain phenothiazinium compounds that are biologically active and suggests that in a series of N, N, N, N-tetra-n-C de-6 alkyl derivatives the tetra- n-Butyl is the most active with activity that decreases rapidly as the number of carbon atoms in the chain increases. Surprisingly, derivatives of additional phenothiazinium compounds which are biologically active and which are suitable for use as medicaments have now been found, particularly in the prevention of microbial infections and in the treatment of cancer and microbial infections. In accordance with the present invention, a phenothiazinium compound of the formula (I) is provided for use as an antimicrobial agent for the prevention of microbial infections: ) wherein: R1, R2, R3 and R4 are each independently an optionally substituted linear, branched or cyclic hydrocarbon group, or R1 and R2 or R3 and R4 together with the N atom to which they are attached form a ring of 5, 6 or 7 members optionally substituted; Xp- is a contranion; and P is 1, 2 or 3. For the prevention of wound infections, the wound site is sterilized and in this specification sterilization means a significant reduction in bacterial load, on, at or around a wound site that helps promote efficient wound healing and minimize the likelihood of infection of the wound. The use of the compounds of the formula (I) for the prevention of infection is preferably by PDT in which the compound is applied at a wound site followed by the application of light. Conventional antimicrobials suffer from the drawback that they have a short lifespan for the prevention of infection and need repeated applications, such as swab application, to maintain their effectiveness. The compounds of the formula (I) have improved properties on antimicrobial agents previously known and used because the prevention effect is prolonged and can be reactivated, as necessary, by additional application of light without the need to re-administer the compound . The site of the wound can be maintained in a sterile condition by continuous exposure to light of an appropriate length or by the intermittent use of light of an appropriate wavelength when necessary. According to a further aspect of the present invention, a phenothiazinium compound of the formula (II) is provided for use as an antiviral agent in which the compound of the formula (II) has the same structure as the compound of the formula ( I) but where R1, R2, R3 and R4 are each independently an optionally substituted linear, branched or cyclic hydrocarbon group, or R1 and R2 or R3 and R4 together with the N atom to which they are attached form a ring of 5, 6, or 7 members optionally substituted; Xp ~ is a contranion; and P is 1, 2 or 3. For use in the prevention of microbial infection and as antivirals wherein the straight and branched chain hydrocarbon groups represented by R 1, R 2, R 3 and R 4 preferably contain from 1 to 12 carbon atoms. In compounds in which the hydrocarbon groups represented by R 1, R 2, R 3 and R 4 are the same, it is preferred that each is linear or branched and that it contains 4 or 5 carbon atoms. In compounds in which R1 = R2- and R3 = R4 and in which R1 / R2 are different from R3 / R4 it is preferred that each is linear or branched and contains 1 to 6 carbon atoms, and in addition the total number of carbon atoms in R1, R2, R3 and R4 is from 8 to 18. In accordance with a further aspect of the present invention, a phenothiazinium compound of the formula (III) is provided for use as an antimicrobial agent in the treatment of a microbial infection in which the compound of the formula (III) has the same structure as the compound of the formula (I) but wherein: i) R1, R2, R3 and R4 are each independently selected from C1-6alkyl Straight chain, branched or cyclic, provided that at least one of R1, R2, R3 and R4 is C7_2 alkyl; or ii) R1, R2, R3 and R4 are each independently selected from straight chain, branched or cyclic Cx-? 2 alkyl in which at least one of RI, R2, R3 and R4 is branched or cyclic; or iii) R1, R2, R3 and R4 are each independently selected from straight chain, branched or cyclic Cx-? 2 alkyl in which R1 and R2 may be the same or different and R3 and R4 may be the same or different provided that at least one of Rl and R2 is not the same as at least one of R3 and R4; or iv) R 1, R 2, R 3 and R 4 are each independently selected from straight, branched or cyclic C 1 - 12 alkyl in which R 1 and R 2 are different, or R 2 and R 4 are different; ov) R 1, R 2, R 3 and R 4 are each independently selected from C 1 -12 alkyl and at least one of R 1 and R 2, or R 3 and R 4 together with the N atom to which they are attached form a ring of 5 , 6 or 7 members optionally substituted. In accordance with one aspect of the present invention, a phenothiazinium compound of the compound of the formula (IV) is provided for use as a medicament or for use as an anticancer agent in which the compound of the formula (IV) has the same structure that the compound of the formula (I) but wherein: i) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C C _? alquilo alkyl, provided that at least one of R1, R2, R3 and R4 is C7-12 alkyl; or ii) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C? -?? alquilo alquilo alkyl in which at least one of R 1, R 2, R 3 and R 4 is branched or cyclic; or iii) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C C _? alquilo alkyl in which Rl and R² may be the same or different and R3 and R4 may be the same or different provided that at least one of R1 and R2 is not the same as at least one of R3 and R4, except for the compound in which R1 and R2 are both HO (CH2) 2- and R3 and R4 are both n-butyl or n-pentyl; or iv) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C C _? alquilo alkyl in which Rl and R² are different, or R² and R 4 are different; ov) R1, R2, R3 and R4 are each independently selected from C? _ ?2 alkyl and at least one of R1 and R2, or R3 and R4 together with the N atom to which they are attached form a ring of 5, 6 or 7 members optionally substituted except for the compound in which R1 and R2 together with the N atom to which they are attached form a morpholino ring and R3 and R4 are both n-butyl; Xp ~ is a contranion; and P is 1, 2 or 3. According to a further aspect of the present invention, there is provided a phenothiazinium compound of the formula (V) in which the compound of the formula (V) has the same structure as the compound of the formula (I) but wherein: i) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C C _? alquilo alkyl, provided that at least one of Rl, R 2, R3 and R4 is C7-i2 alkyl; or ii) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C? -?? alquilo alquilo alkyl in which at least one of R 1, R 2, R 3 and R 4 is branched or cyclic; or iii) R1, R2, R3 and R4 are each independently selected from straight-chain, branched or cyclic? -2-alkyl in which R1 and R2 may be the same or different and R3 and R4 may be the same or different provided that at least one of R1 and R2 is not the same as at least one of R3 and R4, except for the compound in which R1 and R2 are both H0 (CH2) - and R3 and R4 are both n -butyl or n-pentyl; or iv) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C C-2 alquilo alkyl in which Rl and R² are different, or R² and R 4 are different; ov) R1, R2, R3 and R4 are each independently selected from C ?_12 alkyl and at least one of R1 and R2, or R3 and R4 together with the N atom to which they are attached form a ring of 5, 6 or 7 members optionally substituted except for the compound in which R1 and R2 together with the N atom to which they are attached form a morpholino ring and R3 and R4 are both n-butyl; Xp ~ is a contranion; and P is 1, 2 or 3.

In general, straight or branched chain hydrocarbon groups represented by R 1, R 2, R 3 and R 4 in any of the compounds of formulas (I) to (V) may include one or more unsaturated bonds, for example one or more alkene groups , and may be optionally substituted by a selected group of H, F, Cl, Br, I, -OH, -OCalkyl of C? _S / -CN, -OCOalkyl of C? -S or aryl, such as phenyl. These straight and branched chain hydrocarbon groups are preferably unsubstituted and are preferably saturated hydrocarbon groups. The cyclic hydrocarbon groups represented by R 1, R 2, R 3 and R 4 in any of the compounds of formulas (I) to (V) contain from 3 to 8 carbon atoms, preferably from 4 to 6 carbon atoms and most preferably 6 atoms of carbon. These cyclic hydrocarbons can include one or more unsaturated bonds, can be optionally substituted and optionally can include a heteroatom such as nitrogen. Where R1 and R2 and / or R3 and R4 in any of the compounds of formulas (I) to (V) together with the N atom to which they are attached form an optionally substituted 5, 6 or 7-membered ring, the The ring may contain other heteroatoms and may be optionally substituted. The heteroatoms are preferably selected from N, O or S. Where the heteroatom is S, it can be substituted with 0, where the heteroatom is N, this can be substituted with H, -CO C? -6 alkyl or alkyl of C? -6 which is optionally substituted by -OH, preferred substituted heteroatoms are selected from S02, NH, NCH3, NC2H5, NCH2CH2OH and NCOCH3. Optional ring substituents may be selected from C 1-6 alkyl, -OH, -OC alkyl, C 0 -C 0 alkyl. Examples include: wherein Z is CH2, CH2-alkyl of β-β, S, S02, NH, NCH3, NC2H5, NCH2CH20H or NC0CH3. The counter-ion represented by Xp "in any of the compounds of formulas (I) to (V) can be an organic or inorganic counter-ion and is preferably selected from F", Br ", Cl", I ", N03", SCN " , C103", CIO4", BF4", IO3", BF4", HS04 ~, H2P04", CH3S04", N3", S042", HP042 ~, P043", acetate, lactate, citrate, tartrate, glycolate, glycerate, glutamate , β-hydroxyglutamate, glucuronate, gluconate, malate and aspartate Preferably, the counter-ion is selected from the group comprising Cl ", Br", I ", F", N03", HS04", CH3C02", S042", HP042 ~ or P043 ~ or of the group comprising Cl ", Br", I ", acetate, lactate, citrate, tartrate, glycolate, glycerate, glutamate, β-hydroxyglutamate, glucuronate, gluconate, malate, aspartate, and most preferably from the group comprising Cl ", Br", I. "In a preferred subgroup of compounds of the formula (I) to (V) R1, R2, R3 and R4 can be the same or different and the sum of the carbon atoms in the alkyl side chains represented by R1 and R2 is from 14 to 40, preferably from 16 to 36 , and most preferably from 18 to 30, and especially from 18 to 24. In a further preferred subgroup of compounds of formulas (I) to (V) R1, R2, R3 and R4 may be the same or different and the sum of the carbon atoms in the alkyl side chains represented by R1 and R2 is from 16 to 20, preferably from 18 to 20. The phenothiazinium compounds of the formulas (I) to (V) can be synthesized as follows: 1) compounds of symmetrical phenothiazines wherein R1 and R2 = R3 and R4 a) The phenothiazine is first brominated with bromine in glacial acetic acid to give 3,7-dibromophenothiazin-5-io bromide, the suspension formed is collected by filtration. b) 3,7-Dibromophenothiazine-5-io bromide is added to an amine represented by R 1 R 2 NH (where R 1 and R 2 are as defined above) or N-heterocycle in chloroform. The solid formed is collected by filtration and purified, for example, by flash column chromatography on silica gel 60, with the use of chloroform, chloroform / methanol (98/2) and then chloroform / methanol (90/10). The product can be further purified by precipitation from chloroform with petroleum ether (e.g., 60-80 ° C). 2) The non-symmetric phenothiazinium compounds where R 1 and R 2? R3 and R4, or where Rl? R2 and / or R3? R4 a) The phenothiazine in chloroform is cooled below 5 ° C and a solution of iodine in chloroform is added. The solid formed is collected by filtration, washed with chloroform until it is free of iodine and then kept at room temperature under vacuum overnight to give phenothiazin-5-io hydrated tetraiodide. b) The phenothiazin-5-io tetraiodide hydrated in methanol is added to a solution of amine R 1 R 2 NH in methanol (in which R 1 and R 2 are as defined above). The reaction mixture is stirred overnight, reduced by evaporation and allowed to cool. The solid that forms is collected by filtration, washed with diethyl ether and dried. c) Triethylamine in dichloromethane followed by a solution of a second amine R3R4NH different (in which R3 and R4 are as defined above) in dichloromethane is added to a solution of solid b) above in dichloromethane. The reaction mixture is stirred overnight, the organic layer is washed with dilute hydrochloric acid and water, separated and dried (MgSO4). Most of the solvent is evaporated and diethyl ether is added to precipitate the product which is collected by filtration, washed with diethyl ether and dried. Further purification of the product, if necessary, can be by flash column chromatography. Compositions comprising a compound of the formula (V), together with one or more pharmaceutically acceptable carriers, diluents or excipients (each selected for certain characteristics that allow the optimal formulation of a pharmaceutical composition) form a further feature of the present invention. . The compositions of the present invention also include those which comprise any two or more compounds of the formulas (I) to (V) and those which comprise any of one or more compounds of the formulas (I) to (V) with one or more therapeutic agents or different active The compositions include liposomes, nanoparticles, colloidal suspensions, micelles, microemulsions, vesicles and nanospheres. The compositions may also comprise additional components such as vehicles and conventional delivery excipients including solvents such as alcohols (eg, ethanol, polyethylene glycol, glycerol or n-butanol), dimethyl sulfoxide, water, saline, solubilizers such as derivatives of castor oil, for example castor oil ethoxylates such as Cremofor EL (trademark BASF AG) or Tween (trademark, ICI Americas Inc.) or Solutol HS15 (Solutol is a trademark of BASF AG), isotonizing agents such as urea , glycerol, aminoethanol, propylene glycol, pH regulators, dyes, gelling agents, thickeners, pH regulators and combinations thereof. Typically the compositions are prepared by mixing a compound of the formula (I) with one or more pharmaceutically acceptable carriers at an appropriate temperature, typically 15 ° to 65 ° C at an appropriate pH, typically an appropriate pH, typically a pH of 3. to 9 and preferably at a physiologically acceptable pH, such as pH 6.5 to 7.5. In compositions comprising any one or more compounds of formulas (I) to (V), the concentration of compounds in the compositions depends on the photosensitizing ability of the compound and is preferably in the range of 0.0005 to 20% for topical use and 100 μM at 30 mM for intravenous use. Dry compositions, which can be reconstituted before use, are also provided in the present invention. These can be prepared by dry blending solid components of the composition or preparing a liquid composition which is evaporated to dryness generally under mild conditions under vacuum or in the form of low temperature. The compounds of the formula (IV) and their compositions can be used as medicaments in the treatment of a variety of conditions including infection and cancer; the treatment of dermatological, ophthalmic, cardiovascular, gynecological and dental conditions; and the prevention of infection. Preferably, the use as medicaments is as anticancer, antibacterial, antifungal and antiviral agents. These uses can be in humans or animals. In one embodiment of the present invention, a compound of any of formulas (I) to (V) is used as a PDT agent or photodiagnostic agent. Examples of uses of the various compounds of formula (I) to (V) and their compositions are as photosensitizing drugs for PDT to treat cancer and precancerous conditions including Barrett's esophagus, vulval intraepithelial neoplasia (VIN) and cervical intraepithelial neoplasia ( CIN), bladder cancer, colon cancer, non-melanoma skin cancer, actinic keratosis, melanoma, pituitary-brain cancer, brain glioma, pancreatic cancer, head and neck cancer, lung cancer, particularly cell not small, mesothelioma, esophageal cancer, stomach cancer, cutaneous T-cell lymphoma; for treating systemic and local infections, for example for use as antimicrobial and antifungal treatments for skin infections and wounds such as burn wounds, in the treatment of ulcers particularly leg ulcers, most particularly infected chronic leg ulcers, nail infections; for parasitic infection, stomach infection, malaria, leprosy; for inactivation of bacterial and mycotic spores; for treatment of prions and viral infections such as HIV; for ear, nose and throat infections, tuberculosis, -for sexually transmitted diseases (STD), herpes; for treatment of localized Candida infections for example of hair, nails and epidermis, such as tinea pedis and Candida vulvovaginitis; and for use as an infection preventive such as surgical wound sterilization, skin graft sterilization, stem cell sterilization, graft versus host disease; to treat ophthalmological conditions such as macular degeneration, occult choroidal neovascularization (CNV), CNV due to pathological myopia, occult with age-related macular degeneration (AMD), diabetic macular edema; for vascular problems such as cardiovascular disease, arteriosclerosis and restenosis; for autoimmune diseases such as rheumatoid arthritis; for skin diseases such as psoriasis, acne, vitiligo and eczema and other dermatological conditions such as hirsuitism and sun damage, other benign conditions such as endometriosis and menorrhagia; for the treatment of bacterial dental diseases such as gum abscesses, gum disease, gingivitis, and removal, deactivation or death of plaque biofilms. The compounds can also be used in photochemical internalization (the use of photosensitizers to aid absorption and subcellular localization of drugs) through their photosensitizing properties and in non-therapeutic uses such as photodiagnostics through their fluorescence properties. This latter approach has the advantage of the fact that the photosensitizer is more concentrated in tumors than in surrounding healthy tissue and when it is induced to fluoresce (by application of blue light), the tumor fluoresces more strongly than the surrounding tissue. Examples of application areas include diagnosis for oral diseases and for diseases of the bladder, lung and skin. The compounds of any of formulas (I) to (V) and their compositions can be used as photosensitizing drugs for PDT in veterinary applications, for example, in the treatment of cancers such as ear cancer in cats, as antifungal, antibacterial treatments. and antivirals, for sterilization of wounds in animals and for ophthalmic treatments in animals. The use of any of the compounds of formulas (I) to (V) and their compositions is preferable in localized and / or early cancer treatments and / or precancerous lesions in humans and animals; or in the treatment and / or prevention of infections in wounds or skin in humans and animals. The compounds of formulas (I) to (V) are particularly useful as photosensitizing drugs for PDT of conditions wherein the treatment requires the removal, deactivation or death of unwanted tissue or cells such as cancer, precancerous disease, ophthalmic disease, disease vascular, autoimmune disease and proliferative conditions of the skin and other organs. Specific and unanticipated advantages of these materials relate to their ability to be photoactive against target tissues at different times after systemic administration (according to the particular sensitizer used) and therefore their ability to be directed to an objective directly eg to the vasculature or tumor cells. They also have a low tendency to sensitize the skin to ambient light when administered systemically and a low tendency to color the skin. In general terms, any of the compounds of formulas (I) to (V) and their compositions can be used in the treatment of various conditions and diseases described by systemic, topical or local administration, followed by application of light of a dose and wavelength or appropriate wavelength range. Where compounds are administered systemically they can be delivered for example intravenously, orally, subcutaneously, intramuscularly, directly into affected tissues and organs, intraperitoneally, directly into tumors, intradermally or by means of an implant. Where they are administered locally or topically, the compounds can be delivered by a variety of means, for example, by a spray, lotion, suspension, emulsion, gel, ointment, thick ointments, sticks, soaps, liquid sprays, aerosols in powder, drops or paste. For the present compounds, the activation is by light, which includes white light, of an appropriate wavelength, generally in the range of 600 to 800 nm, the preferred wavelengths are from 630 nm to 700 nm. The light source can be any suitable light source such as a laser, a laser diode or a non-coherent light source. The dose of light administered during PDT can vary but is preferably from 1 to 200 J / cm2, most preferably from 20 to 100 J / cm2. Exposure to light can occur at any time after a drug is initially administered or up to 48 hours after drug administration and the time can be adjusted according to the condition being treated, the drug delivery method and the specific compound of the formulas (I) to (V) used. Exposure to light preferably occurs at any time after a drug is initially administered for up to 3 hours, most preferably from the time after a drug is initially administered up to 1 hour, especially up to 10 minutes. The increased intensity of the light dose usually reduces the exposure times. It is preferred that exposure to light be localized to the area / region to be treated, and where tumors are most preferably located to the tumor itself. In one embodiment of the present invention, the compound of formula (I) to (V) or its composition is preferably administered to a subject in need of treatment and exposure to light is given up to 10 minutes after the drug is initially administered. In a further preferred embodiment of the invention, exposure to light is given within 1 minute after a drug is initially administered. Most preferably, exposure to light occurs at the drug delivery site.

The compounds of the present invention have the advantage, compared to other phenothiazinium photosensitizers, that when carrying out their cell-killing activity they are not directed to the nucleus of the cell so there is a much lower risk of the cells suffering mutagenic transformations. Microbial infections The compounds of the formulas (I), (II) and (III) have a number of advantages for the prevention and treatment of microbial infections, including bacterial, mycotic and viral infections: • Highly effective in deactivating a wide range of microbial infections. microorganisms, which include gram-positive and gram-negative bacteria, MRSA and fungal infection. • Assets against quiescent / stationary bacteria.

• High selectivity for microorganisms with minimal damage to the tissue of the host. • Unexpectedly low photobleaching level. Wherein a compound of the formulas (I), (II) and (III) or its composition is used in PDT as a photoactivatable antimicrobial to prevent or treat a microbial infection, which includes bacterial, mycotic and viral infections, the treatments for the skin and other local infections, for sterilization of burn wounds and other injuries, treatments for ulcers, for sterilization of both recipient tissue and donor tissue during organ transplantation, including skin, and for the treatment of dental microbial disease, is administered systemically , locally or topically (by any of the means described above) by applying to the area to be treated a therapeutically effective amount of the compound and by exposing the area to the light to be active the compound. The compounds of the formula (I) can be applied to prevent infection at any stage including wound contamination, wherein the non-replicating organisms are present in a wound; the colonization of wounds where the replicating microorganisms occur in a wound; and infection of wounds where the replicating microorganisms are presented which cause injury to the host. Where there is > 10 CFU / g of tissue, sepsis is more likely to develop. The concentration used to kill bacterial cells in vitro is in the range of 0.1 to 100 μM, preferably 1 to 50 μM and most preferably 5 to 20 μM, especially 10 μM. In one embodiment, the prevention of microbial infections preferably comprises the step of administering a compound according to formula (I) wherein R 1, R 2, R 3 and R 4 can be the same or different and can be independently selected from ethyl, -propyl, n-butyl, n-pentyl, i-pentyl, 2-ethylpiperidino, 2-methylpyrrolidino and cyclohexyl. In one embodiment, the treatment of microbial infections preferably comprises the step of administering a compound according to formula (III) in which R1, R2, R3 and R4 can be the same or different and are independently selected from methyl, ethyl, n-propyl, n-butyl, i-butyl, n-pentyl, i-pentyl, n-hexyl, cyclohexyl, MeO (CH2) 2- or HO (CH) 2- wherein at least one of R1 and R2 and / or R3 and R4 together with the N atom to which they are attached form a ring of piperidino, 2-ethylpiperidino, -methylpyrrolidino or morpholino except for compounds in which Rl = R2 = R3 = R4 = methyl, ethyl or n-hexyl and for the compound in which R1 = R2 = HO (CH2) 27- and R3 = R4 = n-butyl. Preferred compounds for use in the prevention of microbial infections or for use as antivirals are the following: 3,7- (tetra-n-butylamino) -phenothiazin-5-io; 3,7- (tetra-n-pentylamino) -phenothiazin-5-io; 3,7- (tetra-iso-butylamino) -phenothiazin-5-io; 3,7- (tetra-iso-pentylamino) -phenothiazin-5-io; 3- (N, N-di-methylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-ethylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-pentylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-hexylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-iso-pentylamino) -phenothiazin-5-io; 3- ((N-ethyl-N-cyclohexyl) amino) -7 ((-N-ethyl) -N-cyclohexyl) amino-phenothiazin-5-io, -3,7-di (piperidino) -phenothiazin-5- io; 3- (2-ethylpiperidino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (2-methylpyrrolidino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3-morpholino-7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3-morpholino-7- (N, N-di-n-butylamino) -phenothiazin-5-io; 3-morpholino-7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-diethanolamino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-dimethoxyethylamino) -7- (N, N-di-n-butylamino) -phenothiazin-5-io; and 3, 7- (tetra-benzylamino) -phenothiazin-5-io. These compounds preferably include a halide as a counter-ion which is preferably Cl ", Br" or I ". Especially preferred compounds for use in the prevention of microbial infections or for use as antivirals are the following: 3, 7- (tetra-n) -butylamino) -phenothiazin-5-io; 3, 7- (tetra-n-pentylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di) -n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-pentylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N , N-di-n-hexylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; and 3- ((N-ethyl-N-cyclohexyl) amino) -7 ((- N-ethyl) -N-cyclohexyl) amino-phenothiazin-5-io The compounds of the formulas (I) and (III) are preferably used against bacteria, most preferably the compounds are used against antibiotic-resistant bacteria. of the formula (IV) have a number of advantages for the treatment of cancer: • Extremely strong photoactivity when s e compares with methylene blue and ethylene. • Low light absorption in the UV / blue region. This results in a lower propensity of the compounds to photosensitivity of the skin. • Rapid skin lightening. • High selectivity for tumors. • Low toxicity in the dark. • Low potential for DNA damage when compared to methylene blue. • Very short light-time drug interval compared to existing PDT drugs. Where the compounds of the present invention are used as PDT agents for mammalian cells and tumors can be administered by using the compositions described above in a variety of ways, such as systemically, topically or locally (by any of the means described above) ) and can be used alone or as components or mixtures with other components and drugs. The dose rates of the compounds of the formula (IV) for intravenous administration to humans for oncological treatments are in the range of 0.01 to 10 μmol (micromole) / kg, preferably in the range of 0.1 to 2.0 μmol (micromole) / kg . To achieve a dose of, say, 2 μmol (micromol) / kg in a 70 kg patient requires 70 ml injection of a 2mM solution, or 5 ml at a concentration of 27mM (16mg / ml) or 2.8 ml of a 50mM solution. Typical injection volumes are in the range of 0.1 to 100 ml, preferably 5 to 50 ml. In one embodiment, the method for treating cancer comprises the step of administering a compound according to formula (IV) wherein R 1, R 2, R 3 and R 4 are independently selected from ethyl, n-propyl, n-butyl, -butyl, n-pentyl, i-pentyl, n-hexyl, 2-ethylpiperidino, 2-methylpyrrolidino, cyclohexyl, benzyl and H0 (CH2) 2, preferably wherein R1, R2, R3 and R4 are independently selected from ethyl, -propyl, n-butyl, i-butyl, n-pentyl, i-pentyl, n-hexyl, 2-ethylpiperidino, 2-methylpyrrolidino and benzyl. In the phenothiazinium compounds of the formula (IV) for use as a medicament or for use as an anticancer agent, each of R1, R2, R3 and R4 is preferably independently selected from ethyl, n-propyl, n-butyl, i-butyl, n-pentyl, i-pentyl, n-hexyl, 2-ethylpiperidino, 2-methylpyrrolidino, cyclohexyl, benzyl and H0 (CH2) 2, most preferably wherein R1, R2 , R3 and R4 are independently selected from ethyl, n-propyl, n-butyl, i-butyl, n-pentyl, i-pentyl, n-hexyl, 2-ethylpiperidino, 2-methylpyrrolidino and benzyl. Sterilization / disinfection of articles / surfaces In accordance with a further feature of the present invention, the compounds of the formula (V) can be used as photoactivated antimicrobial agents, including antibacterial, antifungal and antiviral agents for general surface sterilization and fluids, for example they can be used to sterilize surgical implants and stents, particularly where they are coated or impregnated, to sterilize textiles such as bandages and bandages, IV lines and catheters, for sterilization of water, air, blood, blood products and food and food packaging to avoid transfer of infection, and for domestic, hospital and general office cleaning. The compounds can be applied directly or put in contact with surfaces and fluids and activate the compound when exposed to light. In addition, the surface to be sterilized can be immersed in a mixture of a solution of the compound or the fluid to be sterilized can be mixed with the compound or a solution or mixture containing the compound. Specific advantages of these compounds over existing known antimicrobial photosensitizers are their high photocytotoxicity at low light levels, combined with a low tendency to suffer photobleaching. The present invention further provides a conjugate or mixed material formed between a compound of the formula (V) and a polymer. The term "mixed material" as used herein refers to the situation wherein a compound of the invention is embedded in a polymer or physically occluded within or adsorbed onto a matrix or substrate. The polymer can be a biological polymer such as a peptide or a protein. Preferred polymers include those having, anhydride and / or ester groups. Preferred compounds of formula (V) which form a conjugate or mixed material with a polymer are those in which at least one of R1 and R2 and / or R3 and R4 together with the N atom to which they are attached form a piperazinyl group. The present invention further provides a compound formed by the reaction between a compound of the formula (V) and a chlorotriazine derivative. The chlorotriazine derivative can be a polymer having clo.rotriazine groups attached thereto. The appropriate compounds of the formula (V) can be attached directly to a surface of an article, particularly a polymeric surface or through a conjugate or mixed material formed between a compound of the formula (V) and a polymer or through a derivative of chlorotriazine, permanently by covalent bonds or reversibly by intramolecular interactions. This provides a surface that can be sterilized whenever required by the application of light and is particularly useful, for example, with intravenous lines in patients and in sutures and catheters and intravenous lines, where the maintenance of long-term sterility of the relevant surfaces is problematic. The resistance of the compounds to - Photobleaching is an advantage in those applications, where prolonged color stability is required. In accordance with the present invention, there is further provided an article having at least one surface to which a compound of the formula (V) is attached. Preferably, the article is a medical device such as a venous, urinary or balloon catheter, suture, orthopedic or artificial implant, heart valve, surgical screw or bolt, pacemaker terminal, feeding or breathing tube, vascular stent, infra-ocular lens or small joint replacement. The article can also be used in wound care and to pack materials for medical use, for example, materials for medical equipment. A compound of the formula (V) can be applied or contacted with walls, floors and ceilings of hospitals, clinical surfaces such as operating tables, traces, for cleaning rooms in scientific laboratories, fibers that can be converted into woven textile articles. , knitted or non-woven fabrics such as cleaning cloths, cloths, surgical gowns, bandages for wound dressings and bandages. The compound can be applied directly or by binding to a polymeric species.

Where the composite is to be applied to walls, floors, ceilings and work surfaces, it is contemplated that it will be used as a component of a paint or lacquer, comprising the composite, film-forming polymers, which may or may not be interlaced and a suitable solvent, optionally with drying agents and other colorants. The surface coating may take the form of a water-based solution or dispersion. Alternatively, the article is one for use in the food and beverage industry and may be a packaging article, a wrapping or storage cardboard box or a piece of processing equipment. The item can be a refrigerator, vending machine, ice maker, a piece of restaurant equipment or another kitchen appliance. The present invention further provides the use of a compound of the formula (V) to sterilize a surface or a fluid comprising contacting or applying the compound of the formula (V) to the surface or fluid and activating the compound by means of light The compound of the formula (V) can be contacted or applied by any means, for example as a spray, liquid, solution, suspension, foam, cream, gel or emulsion. In accordance with a further aspect of the present invention, there is provided the use of a compound of the formula (I) to (V) to sterilize fluids in which the fluid is contacted with any of a compound of the formulas (I). ) to (V) or with a conjugate or mixed material formed between any of a compound of the formula (I) to (V) and a polymer while the compound or the conjugate or mixed material is illuminated. The fluid can be a liquid or a gas or a vapor. The method can be applied, for example, for the sterilization of liquids, for example for sterilization of water, or medically used liquids such as parenteral fluids for example saline or glucose and particularly for sterilization of biological fluids such as blood, blood products. , red blood cells, bone marrow cells and stem cells. The method can also be applied for the sterilization of gases such as air, particularly air used in air conditioning systems, and medically used oxygen. This method is particularly useful for sterilizing materials that can not be easily sterilized by filtration methods. The method is preferably used for the sterilization of water, or medically used fluids such as parenteral fluids such as saline or glucose - and for sterilization of biological fluids such as bone marrow cells and stem cells.

Any of the compounds of the formulas (I) to (V) and their conjugates or mixed materials can be used as such, preferably with its surface area maximally augmented such as in a finely divided form or in the form of beads or plates, or may be used in or associated with any support material that provides a large surface area such as glass, wool glass, ceramics, plastics, metals and metal oxides. The support material is preferably transparent to light to allow light to pass therethrough. Where a support material is used, it is arranged to maximize the surface area covered by the conjugate or mixed material and may be in the form of beads, plates, large surface areas in columns or tubes, foams or fibers. Any of the compounds of the formulas (I) a (V) or its conjugates or mixed materials is preferably continuously illuminated at the wavelengths and light doses described above. The preferred compounds of formulas (I) to (V) are those preferred in this sterilization method. In a particular embodiment of this aspect of the invention, any of the compound of formulas (I) to (V) or their conjugates or mixed materials either alone or on a support material is packed in a column, typically made of a material which is transparent to light, such as silica glass or synthetic fibers. The fluid that requires sterilization is passed to one end of the column, the entire column is continuously illuminated and the sterilized material flows out of the other end of the column. Certain novel compounds of the present invention include: 3,7- (N, N-tetra-iso-butylamino) -phenothiazin-5-io; 3,7- (N, N-tetra-iso-pentylamino) -phenothiazin-5-io; 3- (N, N-di-methylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-ethylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io, -3- (N, N-di-n-pentylamino) -7 - (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-hexylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-iso-pentylamino) -phenothiazin-5-io; 3- (N, N-di-methylamino) -7- (N, N-di-n-octylamino) -phenothiazin-5-io; 3- ((N-ethyl-N-cyclohexyl) amino) -7 ((-N-ethyl) -N-cyclohexyl) amino-phenothiazin-5-io; 3,7 di- (piperidino) -phenothiazin-5-io; 3- (2-ethylpiperidino) -7- (N, N-di-n-pentylamino) -f-enothiazin-5-io; 3- (2-methylpyrrolidino) -7- (N, N-di-n-pentylamino) -f-enothiazin-5-io; 3 - (morpholino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (morpholino) -7- (N, N-di-n-butylamino) -phenothiazin-5-io; 3- (morpholino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-diethanolamino) -7- (N, N-di-n-butylamino) -phenothiazin-5-io; 3- (N, N-diethanolamino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-dimethoxyethylamino) -7- (N, N-di-n-butylamino) -phenothiazin-5-io; and 3,7- (N, N-tetra-benzylamino) -phenothiazin-5-io. These compounds preferably include a halide as a counter-ion which is preferably Cl ", Br" or I "The novel potions of the present invention have unexpected advantages over compounds described in PCT / GB02 / 02778. For example: 3.7- ( N, N-tetra-iso-butylamino) -phenothiazin-5-io when compared to the n-butyl analog surprisingly causes minimal tissue damage when used as an anticancer agent and is Ames-negative; 3, 7- ( N, N-tetra-iso-pentylamino) -phenothiazin-5-io when compared to the n-pentyl analog is surprisingly effective at a shorter drug to light interval: 3- (N, N-di-methylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io has improved antibacterial activity when compared with both tetramethyl and tetra-n-propyl derivatives; 3- (N, N-di-ethylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io has improved antibacterial activity when compared with both tetraethyl and tetrapyr derivatives ropyl; 3- (N, N-di-n-butylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io has better antibacterial activity and better Ames performance when compared to derivatives of tetran-propyl and surprisingly is equivalent to the antibacterial activity and Ames yield of the tetra-n-butyl derivative when it is expected to be a little worse; 3- (N, N-di-n-pentylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io has better antibacterial activity and better performance of Ames when compared to tetra n derivative -propyl and surprisingly is equivalent to the antibacterial activity and Ames yield of the tetra n-pentyl derivative when it is expected to be a little worse; 3- (N, N-di-n-hexylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io has better antibacterial activity when compared with both the tetra-n-hexyl derivatives as tetra n-propyl, and has better performance than the tetra-n-hexyl derivative as an anticancer agent and has equivalent yield as an anti-cancer agent at half the dose regimen of the tetra-n-propyl derivative; 3- (N, N-di-n-butylamino) -7- (N, N-di-pentylamino) -phenothiazin-5-io has better activity against Candida albicans than the tetra n-pentyl derivative and almost the same activity than the n-butyl tetra when it is expected to be a little worse; 3- (N, N-di-n-butylamino) -7- (N, N-di-iso-pentylamino) -phenothiazin-5-io has better activity against Candida albicans than both the n-butyl tetra derivative and tetra n-pentyl; 3- (N, N-di-methylamino) -7- (N, N-di-n-octylamino) -phenothiazin-5-io has better antitumor activity than the tetramethyl derivative and causes minimal damage to normal tissue when used as an anticancer agent; 3- ((N-ethyl-N-cyclohexyl) amino) -7 ((-N-ethyl) -N-cyclohexyl) amino-phenothiazin-5-io has better antitumor activity than the tetraethyl derivative and has better antibacterial activity compared both with tetraethyl and tetra-n-hexyl derivatives; 3- (2-ethylpiperidino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io when compared to the tetra n-pentyl derivative is effective at a shorter drug-to-light interval; 3- (2-methylpyrrolidino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io when compared to the tetra n-pentyl derivative is effective at a shorter drug-to-light interval; and 3, 7- (N, N-tetra-benzylamino) -phenothiazin-5-io has better antitumor activity than the tetramethyl derivative. EXAMPLES 1) General Synthesis of symmetrical phenothiazinium bromide of the formula (I) wherein R 1 = R 2 = R 3 = R 4, or R 1 and R 2, and / or R 3 and R 4 together with the N atom to which they are attached form an N -heterocycle; P = 1, Xp "= Br") a) Preparation of 3, 7-dibromophenothiazine-5-io bromide To a solution of phenothiazine (2.00 g, 0.01 mol) (Note 1) in oxygen-free glacial acetic acid (150 cm3) was added, in one portion and with vigorous stirring, a solution of bromine in oxygen-free glacial acetic acid (100 cm3, 10% v / v Br2). The reaction mixture became dark with the formation of a dark solid. Stirring was continued for one minute and then water (400 cm3) was added, when the suspension took on a red appearance. The reaction mixture was filtered under vacuum to yield a dark solid and a brown filtrate. The solid was washed with ether and dried under vacuum (40 ° C, 50 mmHg) for one hour to give a brick-red product. Mass of solid = 3.63 g. Performance = 83%. b) Preparation of symmetrical phenothiazinium bromides To a solution of the appropriate R1R2NH amine or N-heterocycle (32.4 mmol) in chloroform (200 cm3) under nitrogen and with vigorous stirring was added, in one portion, bromide of 3-7. dibromophenothiazin-5-io (2.0 g, 4.6 mmol). The reaction mixture became blue in color and stirred under nitrogen for 3 hours. The chloroform solution was washed successively with HBr (2% aq., 2 x 50 cm 3) and water (2 x 50 cm 3), and then dried over MgSO 4. After filtration, most of the solvent was removed by rotary evaporation, an excess of diethyl ether was added and the reaction mixture was then allowed to stand. After some time, a large amount of colorless solid was deposited. This material was removed by filtration. The filtrate was evaporated to dryness and the residual crude product was purified by flash column chromatography on silica gel 60, with the sequential use of a mobile phase of chloroform, chloroform / methanol (98/2) and finally chloroform / methanol. (90/10). The relevant blue chromatographic fractions were combined and the solvent was removed by rotary evaporation.

The dark blue product was collected in a minimum volume of dichloromethane (10 cm3) and the final product was precipitated in crystalline form by the addition of an excess of petroleum ether (e.g., 60-80 ° C). The solid was collected by filtration, washed with ether and dried with air. The purity of each product was confirmed by thin-layer chromatography (showing a single detectable blue dot) and the structure was confirmed by electroaspersing mass spectrometry and absorption spectroscopy.

UV / visible. 2) General Synthesis of symmetrical phenothiazodium iodides of the formula (I) wherein (R 1 R 2 N? R 3 R 4 N or R 1 and R 2, and / or R 3 and R 4 together with the N atom to which they are attached form an N-heterocycle, P = 1, Xp ~ = I ") a) Preparation of phenothiazine-5-io hydrated tetraiodide To a stirred solution of phenothiazine (10 mmol) in chloroform (100 cm3) cooled to below 5 ° C in an ice bath a solution of iodine (33 mmol) in chloroform (400 cm3) was added over 1.5 hours.The mixture was stirred for 30 minutes and the resulting precipitate was collected by filtration, washed with chloroform until free from iodine and maintained at room temperature under vacuum overnight to give the product b) Preparation of nonsymmetric phenothiazine-5-iodide iodides To a stirred solution of phenothiazine-5-io hydrate tetraiodide (1.4 mmol) in methanol (300 cm3) was added, dropwise, over a period of 60 minutes a solution of the appropriate R1R2NH amine (3.6 mmol) in methanol ( 50 cm3). The reaction mixture was stirred overnight. The volume of the reaction mixture was then reduced by evaporation and the hot solution allowed to cool. The solid that formed was collected by filtration, washed with diethyl ether and dried. c) To a solution of this solid (0.34 mmol) in dichloromethane (100 cm3) was added a solution of triethylamine (0.40 mmol) in dichloromethane (5 cm3) followed by a solution of a second amine R3R4NH different (1.4 mmol) in dichloromethane (50 cm3) for 60 minutes. The reaction mixture was stirred overnight. The organic layer was then washed with dilute hydrochloric acid (4 x 25 cm3) followed by water (2 x 25 cm3). The organic layer was then dried (MgSO). The majority of the solvent was removed by rotary evaporation and an excess of diethyl ether was added to precipitate the solid. The solid was collected by filtration, washed with diethyl ether and dried. Further purification of the compound, if necessary, was by flash column chromatography. The purity of each product was confirmed by thin layer chromatography (a single detectable blue dot). The structures were confirmed by electroaspersion mass spectrometry and UV / visible absorption spectroscopy. The following specific compounds were prepared by the above methods: Compound 1 R1-R4 = n-C3H7: tetra-n-propyl Compound 2 R1-R4 = n-CH9: tetra-n-butyl Compound 3 R1-R4 = n-C5Hn : tetra-n-pentyl Compound 4 R1 - R4 = n-C6H? 3: tetra-n-hexyl Methylene blue (R1 - R4 = n-CH3) Compound 5 and ethylene blue (R1 - R4 = n-C2Hs) Compound 1-6 were examined for comparative purposes. Compounds 1 to 6 have iodide counterions. The compounds 7, 7a, 8, 8a, 8b and 14-29 were made by analogous methods. Compound 9 - 3- (N, N-dimethylamino) -1 ~ (N, N-dipropylamino) -phenothiazin-5-io (20%) iodide This compound was obtained by following the triiodide isolation of 3- (N, N-dipropylamino) -phenothiazin-5-io and subsequent treatment with dimethylamine hydrochloride. Precipitation from dichloromethane by addition of diethyl ether gave lustrous purple crystals. Mass spectrometry: C2oH26N3OS requires m / z = 340; found m / z = 340 (no I was detected by mass spectrometry) Compound 10 - 3- (iV, JV-diethylamino) -7- (N, N-dipropylamino) -phenothiazin-5-ioiodide (15 %) This compound was obtained by following the isolation of triiodide of 3- (N, 2V-dipropylamino) -phenothiazin-5-io and subsequent treatment with diethylamine.Resulting from dichloromethane by the addition of diethyl ether gave lustrous colored crystals purple Mass spectrometry: C22H30N3OS requires m / z = 368, found m / z = 368 (I was not detected by mass spectrometry). Compound 11 - 3- (N, N-dibutylamino) -7- (N, N-dipropylamino) -phenothiazin-5-io (19%) iodide This compound was obtained by following the triiodide isolation of 3- (Ny- N-dipropylamino) -phenothiazin-5-io and subsequent treatment with dibutylamine. Precipitation from dichloromethane by the addition of diethyl ether gave lustrous purple crystals. Mass spectrometry: C26H38N3OS requires m / z = 424; found m / z = 424 (I was not detected by mass spectrometry) Compound 12 - 3- (N, Nd-Pentylamino) -7- (N, N-dipropylamino) -phenothiazin-5-ioiodide (20 %) This compound was obtained by following the isolation of 3- (N, i -dipropylamino) -phenothiazin-5-io triiodide and subsequent treatment with dipentylamine.Resulting from dichloromethane by the addition of diethyl ether gave lustrous colored crystals purple Mass spectrometry: C28H42N3OS requires m / z = 452, found m / z = 452 (I was not detected by mass spectrometry).

Compound 13 - 3- (,. N -dihexylamino) -7- (N, N-dipropylamino) -phenothiazin-5-io (22%) iodide This compound was obtained by following the triiodide isolation of 3- (N / N-dipropylamino) -phenothiazin-5-io and subsequent treatment with dihexylamine. Precipitation from dichloromethane by the addition of diethyl ether gave lustrous purple crystals. Mass spectrometry: C30H46N3OS requires m / z = 480; found m / z = 480 (no I was detected by mass spectrometry) Compound 28 - 3- (N, iV-diethanolamino) -7- (N, N-dipentylamino) -phenothiazine-5-iodide (23 %) This compound was obtained by following the isolation of triiodide of 3- (JN / VJV-dibutylamino) -phenothiazin-5-io and subsequent treatment with diethanolamine.Resulting from dichloromethane by the addition of diethyl ether gave lustrous crystals purple color Mass spectrometry: C2eH38N302S requires m / z = 456, found m / z = 456 (no I was detected by mass spectrometry). Additional compounds have been synthesized and this is summarized in Table A. Compounds 5 and 6 are not compounds of the present invention and are included for comparative purposes. The photosensitizer supply solutions were made in water and / or DMSO and stored in the dark until required. The test solutions were made in pH regulator or solvent or biological medium as required. Spectral and physical properties of the phenothiazinium compounds The spectral data of the phenothiazinium compounds in methanol (Table 1) show that all compounds have absorption peaks in the 650-700 nm region, but that there is considerable variability in the peak position precise. Table 1 - Me, Et, Pr, Bu, Pent, Hex, Hept, Oct in the table above and throughout this specification represent methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl respectively, and that n- and i - indicate normal and iso alkyl chains respectively. Cancer treatment The compounds of the formula (I) were evaluated for PDT efficacy in murine fibrosarcoma RIF-1 cells in culture. The cells were incubated with the phenothiazinium for 1 hour, then washed 3 times with PBS and fresh culture medium was added. The cells were then illuminated with 18 J / cm2 (10mW / cm2) 665 nm of light by a diode laser. The toxicity in the dark was measured in parallel. The MTT test was used to evaluate cell viability 24 hours after treatment. The subcellular localization was also measured in RIF-1 cells after 1 hour of incubation with the phenothiazines by the use of fluorescence microscopy.

The location was measured before and after exposure to light. The sample data for these compounds are shown in table 2. Table 2 Phototoxicity, dark toxicity and subcellular localization of phenotiaziniums in RIF-1 cells These data show that several asymmetric phenothiazinium derivatives (where R1 = R2? R3 = R4) have superior properties as photosensitizers to methylene blue, both in terms of absolute activity and in terms of the ratio of light to dark toxicity. In addition, unlike methylene blue, these compounds are excluded from the cell nucleus.

Antitumor efficacy in vivo Tumor destruction was evaluated in CBA / g mice that had subcutaneous CaNT tumors. The photosensitizer was administered intravenously at doses of up to 16.7 μmol / kg. The dose was reduced to 8.35 μmoles / kg if high levels of morbidity or mortality were observed or if the solubility was limited. At various times after the administration of the photosensitizer, the tumor was superficially illuminated with 60 J / cm2, 50 mW / cm2 of light from a Paterson lamp by using a 660 ± 15 nm filter. The drug-light ranges varied from Oh (in practice, 1-2 minutes) to 96 hours. 72 hours after illumination, a slice in cross section was removed from the center of the tumor parallel to the incident light, an image of it was captured and the macroscopic necrotic area was quantified by the use of image analysis software. The necrosis was expressed as% area of the total tumor slice. The% of tumor necrosis in control tumors was generally <10%. The antitumor activity was categorized: None, 0-10% of tumor necrosis, 11-39% of low tumor necrosis, 40-69% of mean tumor necrosis, 70-100% of high tumor necrosis. The antitumor activity at the optimal dose and drug-light ranges for each compound is shown in Table 4.

Due to the close proximity of the subcutaneous tumor to internal organs such as kidney and liver in mouse, damage to these organs is often observed after PDT in this model. Damage to internal organs after PDT was scored as shown in Table 3. Table 3 Rating system for damage to internal organs The following compounds show relatively high antitumor activity without normal tissue damage (average score = 0). Tetrahexyl, dipentyldiethanol-amine. The following compounds showed relatively high antitumor activity with minimal normal tissue damage (average score <1): Tetraisobutyl, dihexyldipropyl, bismethyloctyl.

Table 4 PDT-induced tumor necrosis in CBA / g mice and after intravenous administration at optimal drug-light dose and range, and photoinactivation of logarithmic phase E. col ± and C. albicans by the use of 10 μM of photosensitizer and illumination with 665n? t? of laser light at a dose of 3.2J / cm2, except for compounds 1, 4, 5, 6 that were illuminated at a dose of 1.3 J / cm2 4 ^ fifteen Ul < l For test results of Ames P = positive, N = negative, WP = weakly positive and n.d = not determined.

The present compounds have a number of advantages over currently available compounds such as Photofrin (trade name, Axcan Pharma PDT Inc) and Fosean (trade name, Bioscience Technology Investment Holdings Limited). For example, the compounds of the present invention are individual isomer-free compounds produced by relatively simple procedures, wherein Photofrin is a complex mixture of porphyrin derivatives. A range of short-term drug administration is desirable both in terms of patient convenience and time in the hospital during treatment and associated costs. Photofrin requires a range of long-term drug administration, typically 48 hours, since unacceptable damage to normal tissues surrounding the tumor occurs at short drug-to-light intervals. The compounds of the present invention are active at short drug-light intervals without any damage to normal tissue surrounding the tumor. For example, the dibutyldipropyl derivative causes 98% tumor necrosis where illumination is immediately after administration. The comparison of damage to the skin that is above the tumor (evaluated by scab formation) shows that with all the compounds present no scab formation is observed in any drug-to-light interval while Photofrin gave up to 25% scab at short drug intervals (0 - 3 hours), drug-to-light intervals longer than 48 hours did not give scab formation but tumor necrosis was only 50%. For another compound available, Fosean, there is a delay of 4 days, to allow time for accumulation of cancer cells, between injection into the bloodstream and activation with laser light. The administration of Fosean results in patients becoming more sensitive to light, with a sensitivity period of approximately 15 days. Photoantimicrobial activity 1) General methods Method for microbial bacterial photoinactivation experiment a) Standard preparation of photosensitizers Stock solutions of the photosensitizers were made up to 5 mM in dimethyl sulfoxide (DMSO). The 5 mM supply was further diluted in DMSO at a working concentration of 1 mM. All photosensitizers were stored in jars covered with aluminum at room temperature until required. b) Standard preparation of microorganisms The standard protocol outlined below was modified as appropriate to study the variation of some experimental parameters.

A single bacterial colony from an agar plate was used to aseptically inoculate 100 ml of nutrient medium (0.5% yeast extract: 1.0% tritone p / v) in a 1 liter conical flask. For C. albicans, a single fungal colony was used to inoculate 100 ml of sabouraud dextrose medium in a 1 liter conical flask. The culture was incubated in an incubator with shaking overnight, at 37 ° C. The incubator was set at 250 strokes per minute and a rotating movement of 2.5 cm in a circle. This culture was used for stationary phase experiments. For bacterial log phase experiments, the overnight culture was used to inoculate 200 ml of nutrient medium (in a 2 liter bevelled flask), for C. albicans 200 ml of sabouraud dextrose medium were inoculated, both were at a density from 0.1 to 600 nm. The microorganisms were grown until they were in the mid logarithmic phase and then harvested and resuspended. c) Preparation of microorganisms for PDT The cells of the log or stationary phase were collected by centrifugation and washed twice in the pH buffer of 0.1 M potassium phosphate (pH 7.0). After washing, the cells were resuspended in the same pH regulator at an absorbance of 0.87 at 650 nm. This absorbance was equivalent to 3.5 x 108 CFU / ml or 8.5 logioCFU / ml for E. coli, S. aureus, MRSA and P. aeruginosa. For C. albicans this was correlated with 1.0 x 107 CFU / ml or 7.0 logioCFU / ml. For photoinactivation of E. coli cells in the medium, the bacteria were resuspended in nutrient medium at this stage. Photoinctivation experiments of microbial cells Standard incubation with photosensitizer 25 ml of the prepared cell suspension was incubated with 0.25 ml of a 1 mM supply of photosensitizer (which gave a final concentration of 10 μM) in a conical flask covered with sterile aluminum of 250 ml. The suspension was incubated for 30 minutes in the dark and in an incubator with shaking at 37 ° C at 250 rpm. Illumination from a white light source After incubation with 10 μM phenothiazinium compound, the suspension was irradiated with a 500W halogen lamp, from a distance of 75 cm, for 60 minutes, the lamp power was 1.3mW / cm2 which gave 4.68J / cm2 during one hour of illumination. Illumination of a 665nm laser After incubation with phenothiazinium compound μM, 10 ml of the bacterial culture were transferred aseptically to a sterile cell. This consisted of a sealed bottle with a sealed capillary tube inserted, in which the optical fiber could be placed. The illumination was carried out with a Ceram Optec diode laser (665 nm) that used an optical fiber with a diffusion tip of 3 cm, at 100 m. For experiments comparing the series of phenothiazinium compounds in E. coli, the samples were illuminated for 4 minutes. This was equal to a creep rate of 5.3 mW / cm2 which assumes that the lit cylinder area was 18.86 cm2. After 4 minutes of illumination, the total creep was 1.3 J / cm2. Other experiments used illumination for 10 minutes and samples of 50 μl were removed for CFU analysis after 0, 1, 2, 4, 8 and 10 minutes of illumination. These lighting times are equivalent to the following fluences respectively: 0 J / cm2; 0.32 J / cm2; 0.64 J / cm2; 1.3 J / cm2; 2.5 J / cm2 or 3.2 J / cm2. Traces of oxygen electrode showed that oxygen was not limiting during the period of illumination. For experiments comparing the effect of tetra-n-pentyl-3,7-diaminophenothiazin-5-io compound on different bacteria, the illumination used the laser preparation but for 10 minutes which gave a light dose of 3.2J / cm2. The dose of light was also used for experiments comparing compounds 17-29. The results are tabulated above in Table 4. Analysis of bacteria and yeast survival 50 ml of the illuminated and unenlightened samples of the suspension were removed and diluted in pH buffer of 0.1 M potassium phosphate at pH 7.0. 50 μl of the diluted suspension was placed on plates then on nutrient agar (0.5% yeast extract, 1.0% tryptone, 2.0% w / v agar) for bacteria, a sabouraud dextrose agar for C. albicans. Plates were incubated overnight at 37 ° C to give a number of colony forming units between 30-300. The inactivation of cells was then measured. Control studies involving the condition of bacteria before and after the 30 minute incubation step without phenothiazinium compound but with 0.25 ml DMSO showed no change in CFU / ml. Illumination of the bacterial culture alone without phenothiazinium compound but with 0.25 ml of DMSO also showed that there was no change in CFU. For illumination in a nutrient medium, the control tests showed an increase of log? 0 in CFU / ml of 0.2 during one hour of illumination. Determination of the effect of phenothiazinium compound on the growth of bacterial cells 200 ml of nutrient medium (0.5% yeast extract, 1.0% tryptone w / v) in aluminum-covered 250 ml conical flasks were aseptically incubated with 10 ml of fully grown bacterial culture (E. coli). In addition, the medium contained 1.0 ml of a lmM supply solution of phenothiazinium compounds with a final concentration of 10 μM, in addition to the control containing no phenothiazinium but 1.0 ml of DMSO. The suspension was incubated at 37 ° C and 250 rpm in an incubator with shaking in the dark. Samples of 1 ml were taken every hour for 6 hours and turbidity was measured based on apparent optical density at 550 nm caused by light scattering. Control studies show that this wavelength is outside the region of photosensitizer absorption. Following the optical density readings, the 1.0 ml sample was shaken in a MSE Micro-Centaur centrifuge (10,000 g x 5 minutes) and the absorbance spectra of the supernatant were read spectrophotometrically. For the tetra-n-butyl derivative alone, similar experiments were carried out wherein the bacteria were allowed to grow without photosensitizer for 3 hours, after which the phenothiazinium compounds were added. Subsequent growth was monitored as a function of time, both for exposure to light and in darkness. Absorption of photosensitizers in E. coli After incubation of bacteria with photosensitizer, 2 ml of the unenlightened bacterial culture were pelleted by the use of a Benchtop Centaur 5 centrifuge (1500 g x 10 min). The bacterial pellet was washed twice with 0.1 M potassium phosphate pH buffer (pH 7.0) to remove extracellular photosensitizer and loosely bound. Finally, the tablet was resuspended and vortexed in 1 ml of 0.1 M NaOH, 2% (w / v) SDS and left at room temperature, in the dark, for at least 24 hours. The fluorescence readings were taken by using the Kontron SFM-25 spectrofluorimeter. The concentration of phenothiazinium compound in the cellular samples was determined from the interpolation of the standard curves. Photobleaching 0.25 ml of a 1 mM solution of photosensitizer, 0.25 ml of 10 mM tryptophan was added to 25 ml of pH regulator of 60% methanol, 40% potassium phosphate (pH 7.0). The experiments were also carried out in the absence of tryptophan where it was replaced by 0.25 ml of the pH regulator of 60% methanol, 40% potassium phosphate (pH 7.0). The mixture was illuminated as in the previous cell inactivation experiments (1.3 m / cm2) for 60 minutes, the samples were taken every 15 minutes and the spectra were recorded on a UV-Visible spectrophotometer between 500 nm and 700 nm. For high light doses, the illumination was at 9mW / cm2 for 60 minutes. Results Antibacterial properties of phenothiazinium derivatives Many antibiotics are only poorly effective against bacteria that are not growing or are stationary and it is important to evaluate the ability of phenothiazinium compounds to inactivate bacteria in the stationary phase. During a stationary period, the cell has a thicker peptidoglycan cell wall and differences in protein metabolism and therefore may be less susceptible to photodynamic effect. The inactivation of bacteria can be more challenging in a therapeutic environment because the sensitizer can preferably bind to extracellular proteins rather than the bacterial lipopolysaccharide membrane. This was proven by resuspending the bacteria in nutrient medium containing many factors that can compete with bacterial cells for photosensitizer binding. The potential advantages of a laser source are increased precision of light doses and shorter lighting times. The absorption of the photosensitizers in bacterial cells is clearly important to determine the photoactivity. S. aureus is a gram-positive organism that differs from gram-negative organisms in that it has a thick external peptidoglycan layer and has no external lipopolysaccharide. The bacterial structure is the same as in MRSA (S. aureus resistant to methicillin) that is resistant to almost all antibiotics used. The data show that after only 1 minute of illumination almost 99% of the bacteria are inactivated and that after 10 minutes there are almost 5 logs of dead cells, which illustrates the very high photoactivity of tetra-n-butyl derivative against these gram positive organisms. It is important to determine if the photosensitizer would also be the active compound against the antibiotic-resistant form, MRSA, that this would have important industrial and health applications. Antifungal properties of phenothiazinium derivatives To test the ability of the compounds of the formula (I) to kill fungal cells in the light, the photosensitizer was incubated with Candida albicans cells and the culture was subjected to a laser light as described before. The photosensitizer is therefore also highly photoactive against this fungal organism which is responsible for many common infections, eg, canker sores. Selectivity for bacterial cells versus mammalian tissues It is clearly important for therapeutic purposes that there is minimal damage to host tissues as long as the microorganisms are destroyed. This was tested by applying a solution of the compound of the formula (I) to the ears of experimental mice and illuminating, under conditions in which the total dose was almost 20 times that required for the elimination of bacteria or fungi. These possible effects on the tissue of the host were evaluated by measuring any increase in the thickness of the ear. This is a standard model for detecting photodynamic reactions in the skin. The comparison with results for intravenous administration of PHP, a drug equivalent of Photofrin that is known to cause prolonged skin reaction. The PHP reaction is very strong, as expected, there is little or no reaction of the compound of the formula (I), which suggests that the tissues of the mammal are not damaged during the antimicrobial treatment. Photobleaching, photobleaching removes the detectable color of the photosensitizer, making it inactive and is the result of instability to light and reduction or oxidation. Photobleaching can have advantages or disadvantages depending on the potential application. For example, photobleaching is undesirable in the lining of lines and catheters. Two sets of experiments were carried out; one at a high light dose (9.0 mW / cm2) and one at a low light dose (1.3 mW / cm2) with and without tryptophan as described above. The absorption aspects at high light doses, with and without tryptophan, did not show changes for any of the phenothiazinium compounds, which shows that they are stable at this dose. At the high light dose, the spectrum changes were observed for methylene blue, which indicates photobleaching. The maximum absorbance decreased and the peak wavelength changed during one hour of illumination. These changes occurred to the same degree with and without tryptophan. However, none of the other phenothiazinium compounds showed this degradation and remained stable to photobleaching at high light doses. The antibacterial properties to tetra-n-pentyl-3, 7-diaminophenothiazine-5-io are tabulated below in Table 6. Table 6 Photoxnactivation of bacteria and yeasts in the log and stationary growth phase, after incubation with 10 μM of photosensitizer and illumination with 665 nm of laser light at a creep rate of 3.2 J / cm2 The data in the previous table show the log reduction in CFU / ml of bacteria or yeast incubated with 10 μM of photosensitizer, and illuminated by using 665 nm of laser for 10 minutes, at a fluence of 3.2 J / cm2. The susceptibility of bacteria to PDT mediated by phenothiazinium may depend on whether the batteries are gram-positive or gram-negative. Gram-positive bacteria (S. aureus, MRSA) have a highly interlaced peptidoglycan cell wall approximately 25 nm thick. Gram-negative bacteria (E. coli, P. aeruginosa) have a thinner cell wall of 5 nm and a single outer membrane of lipopolysaccharide. The presence of the outer membrane gives an increased resistance of gram negative bacteria to many antibacterial agents. After illumination, the tetra-n-pentyl-3,7-diaminophenothiazine-5-io compound led to reduction of > 3 log in CFU / ml for the log phase, gram negative bacteria (E. coli, P. aeruginosa) and gram positive bacteria (S. aureus, MRSA). Many antibiotics have a low activity against bacteria in the stationary growth phase. The bacteria in the two growth phases differ in their physiology and morphology. Stationary phase cells are less active and more resistant to environmental stress, therefore, they can be resistant to PDT mediated by phenothiazinium. The above table shows that the effectiveness of the tetra-n-pentyl-3,7-diaminophenothiazin-5-io compound is only slightly reduced against cells in stationary phase compared to the log phase cells. MRSA, an antibiotic-resistant S aureus strain is a major cause of nosocomial infection. MRSA and S. aureus are equally susceptible to antimicrobial PDT mediated by tetra-n-pentyl-3,7-diaminophenothiazin-5-io compound. There was a logarithmic reduction of 3.80 log? 0CFU / ml with the use of the tetra-n-pentyl-3,7-diaminophenothiazin-5-io compound against MRSA in log phase. Ames test The Ames test was carried out (with the use of a Discovery Partners International team) in mixed strains of S. typhimurium (TA7001, TA7002, TA7003, TA7004, TA7005 and TA7006) that detect mutagen replacement pairs of bases in both GC and AT sites, and the TA98 strain that detects frame change mutagens (Gee et al, Proc Nati Acad Sci, 91, 11606-11610, 1994). Approximately 107 bacteria in the medium containing enough histidine for 2 cell divisions were incubated (in triplicate) at 37 ° C, 250 rpm for 90 minutes with 6 concentrations of the test agent, solvent control and positive control. Incubations were carried out under light and dark conditions and with and without metabolic activation with rat liver extract S9 (4.5%). The light source was a bank of seven Sylvania Grolux 30 W light bulbs. A 2-fold dilution series of the test agent was used at the higher concentration which was a toxic concentration (i.e., a concentration causing a visible reduction). in the number of cells of a preselection) or the maximum soluble concentration. In the absence of S9, the positive control was a mixture of 4-nitroquinoline N-oxide (500 ng / ml) and 2-nitrofluorene (2 μg / ml). In the presence of S9, the positive control was 2-aminoanthracene (10 μg / ml). After incubation for 90 minutes, the bacteria were diluted with a pH indicator medium lacking histidine and transferred to 384-well plates to give 48 wells by concentration in triplicate. The plates were incubated at 37 ° C for 48 hours, then the positive wells (wells in which the growth of reverse mutants his + had reduced the pH, which produced a color change from purple to yellow) were counted. The results were expressed as positive wells by 48 (mean ± SD). A positive response was defined as an increase related to the concentration in the number of positive wells and a significant increase in the number of positive wells at one or more concentrations of test agent compared to negative control, with statistical significance assessed by the use of a two-tailed Student's t test. The degree of the responses was evaluated by calculating the number of times of increase in the background mutation rate to the optimal test agent concentration (with an increase in number of times of <; 10 classified as a weak positive response). In mixed strains, all compounds tested were negative and all four conditions (± light, ± S9). In strain TA98, all compounds tested were negative in the absence of S9 (± light). In the presence of S9 (± light), some compounds showed a positive response in the TA98 strain, indicating that they are metabolically activated to a framework change mutagen (intercalator). The results in strain TA98 (± s), -light) are shown in table 4 above. Compounds of the formula (I) suitable for inclusion in polymers or bonding to, or absorption on, polymer surfaces (a) Inclusion within polymers Example This can be illustrated by adding 0.01 g of a compound of the formula (V), such as 3, 7- (N, N-tetra-iso-butylamino) -phenothiazin-5-io, to a clear solution of cellulose triacetate (0.5 g) in dichloromethane (10 cm3) and stirring until the compound is dissolves completely. The pouring of the solution onto a glass plate and drying slowly gives a clear film. The film shows typical singlet oxygen generation properties by exposing to light for example an angry red solution of tetraphenylcyclopentadienone (a characteristic singlet oxygen detector) in toluene containing the film is quickly bleached by being exposed to light from a lamp of 40 w tungsten filament. An identical solution did not show bleaching when irradiated during the same period in the absence of the film. (b) Adsorption on polymers This can be illustrated by a phenothiazinium compound (la) which can be made in accordance with the following reaction scheme: in which both groups R = n-pentyl. The compound will be extremely basic and easily protonated in dilute acids to give (Ha) below, which could be strongly adsorbed onto polymeric surfaces, e.g., polyamides, polyacrylates, polyesters, polycarbonates, polyurethanes, and strongly weathered removal by water or solvents. Alternatively, it could be adsorbed directly onto acidic surfaces to give their corresponding cationic salts directly.

He has; R = n-pentyl References Wainwright M, Phoenix DA, Laycock SL, Wareing DRA, Wright PA. (1998). Photobacterial activity of phenothiazinium dyes against methicillin-resistant strains of Staphylococcus aureus. FEMS Microbiology Letters 160, 177-181. "> Wagner SJ, Skripchen or A, Robinette D, Foley JW, Cincotta L (1998) Factors affecting virus photoinactivation by a series of phenothiazine dyes, Photochemistry and Photobiology 67, 343- 349. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (6)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property. 1. A phenothiazinium compound of the formula (I) for use as an antimicrobial agent for the prevention of microbial infections: 0) characterized in that: R1, R2, R3 and R4 are each independently an optionally substituted linear, branched or cyclic hydrocarbon group, or R1 and R2 or R3 and R4 together with the N atom to which they are attached form a ring of 5 , 6 or 7 members optionally substituted; Xp- is a contranion; and P is 1, 2 or 3.
2. 2. A phenothiazinium compound of the formula (II) for use as an antiviral agent characterized in that the compound of the formula (II) has the same structure of the compound of the formula (I) of according to claim 1, but wherein R 1, R 2, R 3 and R 4 are each independently an optionally substituted linear, branched or cyclic hydrocarbon group, or R 1 and R 2 or R 3 and R 4 together with the N atom to which they are attached form a ring of 5, 6, or 7 optionally substituted members; Xp "is a counter-ion, and P is 1, 2 or 3.
3. 3. A phenothiazinium compound of the formula (III) for use as an antimicrobial agent in the treatment of a microbial infection characterized in that the compound of the formula (III) has the same structure as the compound of formula (I) according to claim 1, wherein: i) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic QL-12 alkyl provided that at least one of R1, R2, R3 and R4 is C7_2alkyl, or ii) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C? -? alkyl; wherein at least one of R 1, R 2, R 3 and R 4 is branched or cyclic, or iii) R 1, R 2, R 3 and R 4 are each independently selected from straight, branched or cyclic C 1 -C 12 alkyl in the which Rl and R2 can be the same or different and R3 and R4 can be the same or different as long as at least one of Rl and R2 is not the same as at least one of R3 and R4; or iv) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic straight chain alkyl, wherein R1 and R2 are different, or R2 and R4 are different; ov) R1, R2, R3 and R4 are each independently selected from C1-12 alkyl and at least one of R1 and R2, or R3 and R4 together with the N atom to which they are attached form a ring of 5, 6 or 7 members optionally substituted.
4. 4. A phenothiazinium compound of the compound of the formula (IV) for use as a medicament or for use as an anti-cancer agent characterized in that the compound of the formula (IV) has the same structure as the compound of the formula (I) of according to claim 1, wherein: i) R1, R2, R3, and R4 are each independently selected from straight, branched, or cyclic C, _12 alkyl provided that at least one of R1, R2, R3 and R4 is C7_2 alkyl; or ii) R1, R2, R3 and R4 are each independently selected from C? _ alkyl? straight, branched or cyclic chain in which at least one of R1, R2, R3 and R4 is branched or cyclic; or iii) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C C _? alquilo alkyl in which Rl and R² may be the same or different and R3 and R4 may be the same or different provided that at least one of Rl and R2 is not the same as at least one of R3 and R4; or iv) R1, R2, R3 and R4 are each independently selected from straight chain, branched or cyclic alkyl in which R1 and R2 are different, or R2 and R4 are different; ov) R1, R2, R3 and R4 are each independently selected from C1-12 alkyl and at least one of R1 and R2, or R3 and R4 together with the N atom to which they are attached form a ring of 5, 6 or 7 members optionally substituted, except for the case where Rl and R2 together with the N atom to which they are attached, form a morpholino ring and R3 and R4 are n-butyl; Xp "is a counter-ion, and P is 1,2 or 3.
5. 5. A phenothiazinium compound of the formula (V) characterized in that the compound of the formula (V) has the same structure as the compound of the formula (I) according to claim 1, wherein: i) R1, R2, R3 and R4 are each independently selected from straight chain, branched chain or cyclic alkyl provided that at least one of R1, R2, R3 and R4 is C7_12 alkyl, or ii) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C? _12 alkyl in which at least one of R1, R2, R3 and R4 is branched or cyclic, or iii) R1, R2, R3 and R4 are each independently selected from straight, branched or cyclic C1-12 alkyl in which R1 and R2 may be the same or different and R3 and R4 may be be the same or different provided that at least one of Rl and R2 is not the same as at least one of R3 and R4, except for the compound in which Rl and R2 are both HO (CH2) 2- and R3 and R4 are both n-butyl or n-pentyl; or iv) R 1, R 2, R 3 and R 4 are each independently selected from straight, branched or cyclic C 1 -C 12 alkyl in which R 1 and R 2 are different, or R 3 and R 4 are different; or v) R 1, R 2, R 3 and R 4 are each independently selected from C 1 - 2 alkyl and at least one of R 1 and R 2, or R 3 and R 4 together with the N atom to which they are attached form a ring of 5, 6 or 7 members optionally substituted except for the compound in which R1 and R2 together with the N atom to which they are attached form a morpholino ring and R3 and R4 are both n-butyl; Xp "is a counter-ion, and P is 1, 2 or 3.
6. 6. A composition characterized in that it comprises a compound of the formula (V), together with one or more pharmaceutically acceptable carriers, diluents or excipients. The compound of the formula (IV) according to claim 4, for preparing a medicament 8. The use of any compound of the formulas (I) to (V) according to claims 1 to 5 as a PDT agent or a photodiagnostic agent 9. The use of any compound of formulas (I) to (V) according to claims 1 to 5 for preparing photosensitizing drugs for PDT in veterinary applications 10. The use of any compound of the formulas (I) to (V) according to claims 1 to 5 for preparing photosensitizing drugs for PDT under conditions where the treatment requires the removal, deactivation or death of unwanted tissue or cells. s compounds: 3, 7- (tetra-n-butylamino) -phenothiazin-5-io; 3, 7- (tetra-n-pentylamino) -phenothiazin-5-io; 3,7- (tetra-iso-butylamino) -phenothiazin-5-io; 3, 7- (tetra-iso-pentylamino) -phenothiazin-5-io; 3- (N, N-di-methylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-ethylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-pentylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-i ?; 3- (N, N-di-n-hexylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-iso-pentylamino) -phenothiazin-5-io; 3- ((N-ethyl-N-cyclohexyl) amino) -7 ((-N-ethyl) -N-cyclohexyl) amino-phenothiazin-5-io; 3,7-di (piperidino) -phenothiazin-5-io; 3- (2-ethylpiperidino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (2-methylpyrrolidino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3-morpholino-7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3-morpholino-7- (N, N-di-n-butylamino) -phenothiazin-5-io; 3-morpholino-7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-diethanolamino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-dimethoxyethylamino) -7- (N, N-di-n-butylamino) -phenothiazin-5-io; and 3, 7- (tetra-benzylamino) -phenothiazin-5-io. for the preparation of a composition for the prevention of microbial infections or for use as antivirals. 12. The use of compounds of the formula (V) according to claim 5 as photoactivated antimicrobial agents including antibacterial, antifungal and antiviral agents for the general sterilization of surfaces and fluids. 13. A conjugate or mixed compound formed between a compound of the formula (V) and a polymer in which the compound of the formula (V) according to claim 5. 14. A compound formed by the reaction between a compound of the formula (V) and a chlorothiazine derivative in which the compound of the formula (V) according to claim 5. 15. The use of a compound of the formula (V) according to claim 5 for sterilizing a surface or a fluid comprising contacting or applying a compound of the formula (V) to that surface or fluid and activating the compound by means of light. 16. The use of any of a compound of formulas (I) to (V) for sterilizing fluids, wherein the fluid is contacted with any of a compound of formulas (I) to (V) or with a conjugate or mixed compound formed between any of a compound of the formulas (I) to (V) and a polymer while the compound of the conjugate or mixed compound is illuminated, in which the compounds of the formulas (I) to (V) are according to claim 5. 17. The following compounds: 3,7- (N, N-tetra-iso-butylamino) -phenothiazin-5-io; 3,7- (N, N-tetra-iso-pentylamino) -phenothiazin-5-io; 3- (N, N-di-methylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-ethylamino) -1- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-pentylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-hexylamino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (N, N-di-n-butylamino) -7- (N, N-di-iso-pentylamino) -phenothiazin-5-io; 3- (N, N-di-methylamino) -7- (N, N-di-n-octylamino) -phenothiazin-5-io; 3- ((N-ethyl-N-cyclohexyl) amino) -7 ((-N-ethyl) -N-cyclohexyl) amino-phenothiazin-5-io; 3,7 di- (piperidino) -phenothiazin-5-io; 3- (2-ethylpiperidino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (2-methylpyrrolidino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (morpholino) -7- (N, N-di-n-propylamino) -phenothiazin-5-io; 3- (morpholino) -7- (N, N-di-n-butylamino) -phenothiazin-5-io; 3- (morpholino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-diethanolamino) -7- (N, N-di-n-butylamino) -phenothiazin-5-io; 3- (N, N-diethanolamino) -7- (N, N-di-n-pentylamino) -phenothiazin-5-io; 3- (N, N-dimethoxyethylamino) -7- (N, N-di-n-butylamino) -phenothiazin-5-io; and 3, 7- (N, N-tetra-benzylamino) -phenothiazin-5-io. SUMMARY OF THE INVENTION A phenothiazinium compound of the formula (I) to be used as an antimicrobial agent for the prevention of microbial infections: wherein: R1, R2, R3 and R4 are each independently an optionally substituted linear, branched or cyclic hydrocarbon group, or R1 and R2 or R3 and R4 together with the atom of N to which they are attached form a ring of optionally substituted 5, 6 or 7 members; Xp- is a contranion; and P is 1, 2 or 3. The invention also relates to compositions comprising phenothiazinium compounds, to selected compounds and their use as medicaments, as PDT agents, as photodiagnostic agents, to a conjugate or mixed compound formed between a phenothiazinium and a polymer; and to a method for sterilizing fluids in which the fluid is passed over the conjugate or mixed compound while it is illuminated. The compounds are biologically active photosensitizers that are strongly photocitotoxic and have application in the areas of photodynamic therapy (PDT), as well as for the diagnosis and detection of medical conditions and related uses in photochemical infernalization, in the production of cancer vaccines, in the treatment and prevention of microbial infections and in photo-disinfection or photo-sterilization.