JPS6247844B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a disinfectant containing a metal complex compound of a metal ion and a polyfunctional organic ligand as an active ingredient. Many types of substances have toxic effects on microorganisms. Bactericidal substances have two types of activity. That is, one is bactericidal (bactericidal, germicidal) or virucidal (virucidal), which involves killing microorganisms, and the other is bacteriostatic, that is, bacterial growth inhibition. Bactericidal activity is a property of both inorganic and organic substances, and the use of such activity is important in preservatives, food disinfectants, and other disinfectants.
This is an issue of considerable practical importance in the development of sporicides, virucides and disinfectants. Many inorganic substances have bactericidal activity due to the toxicity of the ions they dissociate and give off, which are toxic to microorganisms or act as oxidizing agents, causing some degree of oxidation of cellular material. Among the inorganic substances that act as disinfectants are salts. The extent to which salt is effective as a toxic substance is
It mainly depends on the degree of dissociation of the salt, the nature of the anion and the valence and molecular weight of the metal ion. In general, divalent cations are more toxic than monovalent cations, and salts of heavy metals are more toxic than salts of lighter metals. The bactericidal activity of heavy metal salts is due to the affinity of their cations for protein substances. The constituent proteins of bacterial cells are insoluble proteinates.
If it precipitates as a substance, the cell will die. But other factors are also involved. The process of inhibiting or killing bacterial growth is influenced by various factors. The most important of these influences is the concentration of the reactants, ie the concentration of the bactericidal substance and the number of bacteria present. The effective concentration of the bactericidal substance depends primarily on two other factors. The first is the presence of moisture, which causes possible ionization of the substance to form the disinfectant and acts as a suspending medium to bring the disinfectant into good contact with the microorganisms. The second is the presence of extra organic and/or other substances that react and render the disinfectant inactive before the disinfectant comes into contact with microorganisms. Metal salts or metal complex compounds have been used as fungicides. Representative prior patents relating to the use of metal salts or metal chelates of inorganic or organic compounds as fungicides include U.S. patent numbers 871392; 991261; 1679919;
1785472; 2208253; 2269891; 2456727;
2494941; 2878155; 2900303; 2901393;
2938828; 3076834; 3099521; 3206398;
3240701; 3262846; 3266913; 3681492 and
3782471. Salts of heavy metals are rapidly precipitated by extraneous organic or other materials, so while such salts can kill initial cells at an initial effective concentration, the combination of extraneous materials and metals is It has been confirmed for bacterial activity that binding causes a rather rapid reduction in the effective concentration, thereby eliminating the amount of toxic metal that is effective for bacterial activity. Therefore, in some cases, inorganic salts dissolve in aqueous media and exhibit dissociative properties that allow them to be used as toxic metal substances, but their effectiveness decreases rather quickly.
Bacterial action cannot be destroyed or controlled or prevented for long periods of time. On the other hand, metal salts or complex compounds of organic moieties, such as organic acids, usually have a degree of dissociation that is not very large compared to, for example, highly soluble inorganic salts. Organic metal salts or metal complexes therefore have relatively great stability and are kinetically inert with respect to the extraneous organic substances present in the environment of living cells, but their stability is high. Therefore, toxic effects are generally low. A brief background question regarding this bactericidal activity includes:
There is also the problem of the relationship between bacterial growth and the acidity or alkalinity of the medium that supports such growth.
The hydrogen ion concentration that allows growth is very low, and generally the hydrogen ion concentration is about 10 ^-4 to ^{10 -7} mol/place. Almost all bacteria grow at a pH of about 7.0 (1 x 10 ^-7 mol/hydrogen ion), but the optimum pH at which they grow best varies depending on the species. The minimum and maximum limits for growth vary widely with species. Therefore, the activity of a bactericide within the PH range of bacterial growth is a very important issue to consider since its activity determines its bactericidal efficacy. In practice, the prior art appears to provide two extreme cases with germicidal metal compositions. One is when the known metal compound has a large degree of dissociation and the toxic metal ion can be obtained quickly and in large quantities by dissociating quickly to form an ionized substance. These ionized substances react in such a way as to saturate all the available ligands, thereby inactivating their bactericidal capacity within a very narrow window of time, losing their residual bactericidal power, and over a long period of time rendering the bactericidal agent inactive. make it relatively ineffective. In other cases, known metal compounds are relatively stable and have an inherently very small degree of dissociation, so normal physiological pH
It provides the least amount of ionized material over the range and therefore the least growth inhibiting or toxic potential. The present invention is based in part on the discovery of bactericidal metal complex compounds with proton-induced dissociative properties that make them particularly unique and effective at hydrogen ion concentrations that are compatible with microbial growth. The active ingredients for fungicidal activity according to the invention are metal complex compounds of metal ions and polyfunctional organic ligands. Metal complex compounds such as
It has been found to have very unexpected dissociative properties within the normal range of approximately physiological PH. Dissociative is
Plotting the negative logarithm of the metal ion concentration versus the negative logarithm of the hydrogen ion concentration on rectangular coordinates (also known as pM -
(known as a PH diagram), can be represented by an S-shaped curve, that is, a curve that curves in two directions like an S-shape. The unique dissociative properties of bactericidal metal complexes make them extremely effective in the controlled release of toxic metal ions from the complex at pHs that are compatible with bacterial growth. These disinfectants are highly effective as disinfectants and bacterial growth inhibitors against microorganisms including bacteria, mycelia, and viruses. Another unique embodiment of the present invention provides a bactericidal metal complex compound that is highly stable at high alkaline PH's of about 9 to about 12. Such complex compounds can therefore be used with great advantage in alkaline media to provide controlled release of fungicidal actives on demand. As will be well seen from the detailed description of the invention and the examples that follow, the fungicides of the invention are active against a wide variety of microorganisms. Further, in another aspect, the present invention provides a method for eliminating conventional disinfectants by using a metal compound of a polyfunctional organic ligand that liberates a large amount of toxic metal ions at a normal physiological pH range of about 4 to about 9. fulfills the requirement in a way not known for. In particular, the fungicides of the present invention liberate large amounts of toxic ions from their coordination structure at a pH of about 7-8 and are effectively unstable at about a pH of 7, where almost all microorganisms grow. These fungicides are very stable and relatively inert towards organic moieties, unlike conventional polyhydric water-soluble salts which usually precipitate. Such fungicides are extremely stable even at high alkaline PH. However, due to demand, these disinfectants release metal ions in a controlled manner at the pH at which almost all bacteria are expected to grow, due to their unique dissociation properties as shown by the S-shaped curve in the pM-PH diagram. The most suitable pH for bacterial growth
The structural material, which can be dissociated on demand and easily incorporated into the internal cellular structure of bacteria, is a unique discovery. The nature of the organic ligands makes the complexes of the invention particularly stable towards extraneous organic moieties present in the bacterial cell or in its surrounding environment. Therefore, the fungicides of the present invention may contain other metal complexes, i.e. metal cations, such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), other amino acids, or similar relatively stable i.e. chemical compounds. Forms complexes with organic ligands, such as those represented by inert ones, and pM
- It should be distinguished from other metal complex compounds that do not cause controlled release or dissociation of toxic metal ions, which is represented by an S-shaped curve in the PH diagram. Rather, known metal complex compounds, due to their stability and chemical inertness, show a tendency to dissociate to a small extent rather linearly over the normal physiological PH range. Furthermore, the present invention provides bactericidal metal complex compounds which, due to their ionic properties, can have high concentrations of water solubility and remain in a stable form. This property of solubility in neutral, acidic or alkaline aqueous media makes it possible to generate concentrations capable of producing toxic metal ions in physiological PH environments as required. Such solubility is achieved by using metal cation-anion components, rather insoluble metal compounds according to the prior art which are substantially insoluble in the aqueous medium, or complexes which are soluble but only slightly dissociated. They should be distinguished from metal complexes, in which metal ions are bound in the state and are therefore hardly available for toxic effects. The disinfectant of the present invention has a combination of heavy metal ions and polyfunctional organic ligands (1):
1, the polyfunctional organic ligand is selected from the group consisting of α-hydroxy or mercaptoaliphatic dicarboxylic acids and α-hydroxy or mercaptoaliphatic tricarboxylic acids, and the complex has a pM -Has a dissociative property represented by an S-shaped curve in the PH diagram plot. A particular example of a metal complex compound is di-alkali cupric citrate ( ), represented by the disodium, dipotassium or dilithium salt of monocopper citrate ( ). These dialkali monocopper citrates have dissociative properties represented by an S-shaped curve where the two curves meet at a point within the PH range of about 7 to about 9. These monocopper () complexes have been found to be very stable in basic media at positions from about 9 to about 12, with an effective stability constant K _eff on the order of about 10 ¹² - about 10 ¹³ . ing. However, the K _eff of monocopper citrate () is about 7 to 8.
The pH is on the order of about 10 ⁵ to about 10 ⁸ . Therefore, around a pH of about 7 to 8, the effective stability constant of copper citrate complex is quite low (1000 to 100,000 times lower), and a considerable concentration of free Cu〓 may be toxic or can be used for stabilizing activity. For example, about 10% of the copper in the complex is in an ionized state around pH 7, while about 0.1% of copper is in an ionized state around pH 9.
% is ionized. This may not be the case for EDTA or polyamine complexes of polyvalent metals such as copper. This is because its stability constant (10 ¹⁴ to 10 ¹⁶ ) varies very little at a normal pH of 7 to 9. like that
EDTA complex compounds exhibit a PH effect on stability constant, and are represented by a smooth, monotonous curve that reaches a limit effect due to proton induced dissociation at a PH value of about 7 to about 9.
Approximately 0.001% in the vicinity to 0.00001% in the vicinity of approximately PH9
Only a small amount of ionized material is produced. These stabilizing or fungicidal complex compounds have a pH of about 3 to about 12.
It will be seen that it works over a range. Above about PH12, the complex compounds tend to be destroyed by the alkaline medium and precipitate from the medium as hydrated metal oxides. Below about pH 6, i.e. from about 3 to about 6, the instability of the metal complex is due to the high concentration of free Cu in solution.
〓, which would affect bactericidal properties and other stabilizing functions as described above. Controlled release is most effective in the intermediate range of about 7 to about 9. That is,
These complex compounds can control the release of about 10% to about 0.1% of the complexed metal ions in the pH range of about 7 to 9, and the released metal ions can be used for coordination, bactericidal and stabilizing functions. can do. In presently preferred embodiments according to the invention, other metal complex compounds of polyfunctional organic ligands may also be used at standard pM
- It will be clear that this corresponds to the type of the present invention which exhibits dissociative properties characterized by an S-shaped curve in the PH diagram. For example, based on the monometallic polyfunctional organic ligand complex compounds of the invention, monovalent or polyvalent, especially divalent Other metal ions, both valent and polyvalent cations, can be used. Complexes of heavier metals are believed to be more toxic than lighter metals. Other polyfunctional organic ligands may be used in place of citric acid, which is specifically exemplified as a preferred embodiment of the invention. However, the citric acid moiety provides a favorable buffering effect at a pH of about 8.5, which is another advantage of metal working fluids stabilized with such metal complex compounds. Among other polyfunctional ligands are various α
Alternatively, there are types of β-hydroxy aliphatic di- or tricarboxylic acids, among which citric acid is also included.
α- or β-mercapto aliphatic di- or tricarboxylic acids can also be included in the molecular form of the metal complex compounds of the present invention with similar results. Generally speaking, in terms of the formula of a metal complex compound, a monometallic complex compound of copper and citric acid corresponds to the formula of a complex compound represented by either of the following structural formulas (A) and (B). Type (A) is considered to be a preferable type in terms of free energy. One proton introduced into the complex structure represented by (A) or (B) prevents the formation of a stable 5- or 6-membered ring. Upon introduction of a proton, only a 7-membered ring is formed by coordination of the acetate group electron donor. Therefore, the complex compound molecules dissociate,
Provide metal ions for toxic or stabilizing effects. In contrast, metal complexes of EDTA or other polyamines require four or more protons to dissociate, and are therefore highly acidic;
This is responsible for the small PH effect exhibited by such complex compounds in the figure. The structures of (A) and (B) can be generally expressed by the following model. (Model A) (Model B) In the above model, the solid line portion represents the chemical bond between atoms in the skeletal structure of the molecule, X, Y and Z represent electron pair donors, (R) represents an atomic or molecular moiety or group, and M represents a metal, and the proton affinity of X is greater than that of Z, Y or R. Therefore, if other Lewis base proton pairs and other metal ions are substituted for oxygen, divalent copper, or for that matter carbon atoms in these structural models, they will form an S-shaped curve in the pM-PH diagram. As shown, the introduction of a single proton or a substance exhibiting similar behavior may be adapted to give a molecule that similarly dissociates. The molecular model is therefore an alternative formula for the stabilizer of the invention. The present invention and its various embodiments and advantages will be better understood by reference to the following examples, detailed description, and accompanying figures which illustrate the preparation of complex compounds and their activity. Preparation of complex compound A Dilithium citrate cuprous () 10 mmol of lithium citrate was dissolved in 10 ml of water. To this solution, 10 mmol of cupric chloride (CuCl ₂ .2H ₂ O) was slowly added with stirring. A deep blue solution was formed. It was neutralized with 10 ml of lithium hydroxide (LiOH.H ₂ O) to a pH of about 7. Evaporation of this solution to dryness yields a deep blue semi-crystalline solid. The solid was ground to a fine powder and the lithium chloride was extracted five times with 50 ml of dry methanol at 35°C. The remaining blue solid was freed of methanol under vacuum and dried. Attempts were made to crystallize the salt using a water-organic solvent system, but the resulting solid was microcrystalline to amorphous because the salt was apparently extremely hygroscopic and the ionized molecules had a large negative charge. The following formula has been proposed for a 1:1 complex compound of copper and citric acid based on the analysis and structural explanation described later. Li ₂ CuC ₆ H ₄ O ₇・XH ₂ O Depending on the degree of hydration, the molecular weight (formula weight) (F.
W.) and the corresponding % copper content are: Li ₂ CuC ₆ H ₄ O ₇・XH ₂ O FW265.51 (X = 0), Cu% = 23.93 FW283.53 (X = 1), Cu% = 22.41 FW301.54 (X = 2), Cu% = 21.07 FW319.56 (X=3), Cu%=19.88 The observed copper content of various dried samples of the solid complex compound ranged from 20% to 23%. The compound (1:1 solid complex) was very well soluble in water. Solutions with concentrations on the order of 2 molar could be prepared quite easily. Up to a pH of 11.5, the water solubility of the compound was not affected. Above this pH, the complex decomposes to form a greenish-brown precipitate, probably hydrated copper oxide. The 1:1 solid complex compound can be used as a stabilizer with or without removal of the lithium chloride formed during its preparation. B Disodium Citrate Cuprous (1) An equimolar solution of copper chloride and sodium citrate was added to water in the same manner as in A above to obtain a deep blue solution with a pH of about 5. Exactly 50 ml of this solution was placed in a separatory funnel. Add an equal volume of anhydrous acetone,
Shake the funnel to mix. Upon standing, a two-phase system formed. The bottom of the funnel contains approximately 25ml of blue liquid phase.
was present in reduced amounts and the upper layer (approximately 75 ml) was slightly cloudy and colorless, becoming clear before shaking. The blue liquid (oily consistency) was removed from the funnel through a stopcock and collected in a second separate funnel. The cloudy surface layer was placed in a beaker and evaporated to dryness on a steam bath. Anhydrous acetone approx.
When 25 ml was added to a second separate funnel, almost immediately a plastic-like substance formed at the bottom of the funnel, which was different from the oily liquid that had been there previously. The surface layer on top of the plastic was placed in a second beaker and designated as surface layer 2. Distilled water was added to the plastic and it immediately redissolved. The total amount of redissolved material
The volume was adjusted to 25 ml, again forming a viscous oily liquid. After the surface layer 1 has been evaporated to dryness, microscopic examination of the dried residue reveals the presence of numerous distinct sodium chloride crystals.
Evaporation of the surface layer 2 resulted in a very fine powder residue containing only a few well-defined sodium chloride crystals. When the twice-extracted blue oil solution was analyzed for copper content, the solution was approximately 125 mg/
It was found that it contains copper. It was initially about 65
mg/represents the concentration of the metal complex compound contained. The significant reduction in the amount of sodium chloride in the surface layer 2 indicates that most of the contaminant by-product salts have been removed. Upon evaporation of a portion of the concentrate, a distinct crystalline material was seen. (2) The method of previous paragraph (1) was repeated. However, the pH of the initially formed blue solution should be adjusted to approximately PH.
5 to approximately 7 by neutralizing the HCI formed with KOH solution. After carrying out the extraction and evaporation steps as above, a concentrate of the metal complex was obtained, which on evaporation yielded a well-defined crystalline material. (3) As in paragraph (1), combining equimolar amounts of copper sulfate and sodium citrate and then
The pH was adjusted to approximately 7 with NaOH. Extraction and evaporation steps of the resulting blue solution as described above resulted in an amorphous powder with no visually discernible crystalline structure. Based on the structural and analytical descriptions provided below, the following formula is submitted for disodium cuprous citrate () prepared in paragraphs (1)-(3) above. Na ₂ CuC ₆ H ₂ O ₇ ·XH ₂ O C Disodium citrate monozinc A stabilizer zinc complex compound similar to the copper complex compound B above was prepared using the following ingredients. 50 ml Cold water 29.4 g Trisodium citrate dihydrate 13.6 g Zinc chloride (ZnCl ₂ ) Concentrated HCl NaOH pellets ZnCl ₂ was ground into fine particles using a mortar and pestle and then dissolved in water. The PH was adjusted to 0.5-1.0 with HCl. Sodium citrate was added slowly and HCl was added to keep the pH below 1.0. When everything was dissolved, the solution was slowly neutralized with NaOH pellets. The material remaining in the solution was decanted at pH 7.2, the pH was adjusted to 8.5-9.0, and then extracted with twice the volume of 50:50 methanol-acetone solution. The material was collected on a Butchner funnel using Whatman #42 paper. Alternatively, the solution can be dried under vacuum at 70°C. D Disodium Citrate Mono-Nickel A nickel complex compound stabilizer was prepared using the following ingredients: 40 ml cold water 38.4 g anhydrous citric acid 47.5 g nickel chloride (NiCl ₂ ) finely powdered NaOH flakes Citric acid was dissolved in water. Nickel salt was slowly added while constantly checking the pH. After all materials were dissolved, NaOH flakes were added slowly (to minimize heat generation) and the PH was adjusted to 4.0-5.0. Approximately 100 ml of liquid containing approximately 117 mg/ml of Ni was obtained. E Disodium Citrate Monomercury A mercury complex compound stabilizer was prepared using the following ingredients. 40ml Water 2.2g Mercury oxide (HgO) 1.9g Citric acid anhydride NaOH pellets Citric acid was dissolved in water and the solution was warmed to below 50°C. HgO was slowly added while stirring vigorously, and the reaction was allowed to proceed until the solution became clear. PH NaOH
The temperature was controlled with pellets so that it did not exceed 50°C. The product material may be crystallized by any of the methods described for the zinc complex compounds of C above. Determination of the degree of dissociation of metal complex compounds The dissociation degree of the 1:1 copper-citrate complex compound prepared by the above technique was determined using a copper () ion characteristic electrode [(Orion Copper) characteristic electrode]
over the PH range of 3-12. A 50 ml (0.0068 mol) sample of copper citric acid 1:1 solution was adjusted to PH
The free copper ion concentration was measured using a copper ion characteristic electrode. The following free copper ion concentration values were obtained at the stated pH: Then, the negative logarithm of copper ion concentration was determined.

[Table] From these data, a pM-PH curve was drawn to determine the relationship between free Cu ion concentration and PH as illustrated in the attached figure. The attached figure shows the −log of metal ion concentration.
The -log of hydrogen ion concentration (ie, pM versus PH) is plotted (solid line) on a rectangular coordinate at the points listed in the table above. This plot shows an S-shaped curve representing the proton-induced dissociation of the metal complex.
In the PH range of about 9-12, the complex is very stable;
Free Cu concentration is low. At a pH of about 7, the complex is relatively unstable and dissociates significantly to free Cu≦, allowing for a stabilizing function. In the range of about 7 to about 9, Cu〓 can be used for controlled release and released from complex compounds.
Cu〓 dissociates by about 10% to about 0.1%. This unexpected dissociation versus PH behavior makes the complex compounds extremely effective as bactericidal or stabilizing agents for metal working compositions. In contrast, the Cu EDTA complex compound curve is shown as a dotted line in the attached figure, which was developed by A.Ringbom.
Complexation in Analytical Chemistry (1963
New York J. Wiley & Sons Publishing, No. 360
(page). As shown in the example, Cu EDTA
The PH effect on complex compounds is represented by a smooth, monotonous curve that reaches a limiting effect at about PH7-9 due to proton-induced dissociation, e.g., only about 0.001% to
Only 0.00001% of ionized substances are produced. The complex compound with a 1:1 ratio of metal to citric acid is M.
Bobtelsky and J.Jordan, J.Amer.Chem.Soc.
67 , 1824 (1945), it seems to be suggested that it exists in dilute solutions. However, no one has reported on the significant bactericidal or emulsion stabilizing activity of these derivatives or the ability to form coordination structures with emulsified particles. Furthermore, these complexes have been discovered together with the unique properties of metal working fluids as detailed herein. Additionally, solid metal complexes of dialkali copper citrate () were prepared, but their solid form was completely unexpected. It was also possible to create highly concentrated solutions of such metal complexes. The properties of these complexes were clearly determined using the following analytical method. Namely: (1) the molar ratio method introduced by Yoe and Jones [Yoe,
JH & Jones, AL: Ind.Eng.Chem.Anal. 16 ,
111 (1944)]; (2) Introduced by Job, Vosburg and Cooper
Continuous change method modified by [Vosburg, WC
& Cooper, GR: J.Am.Chem.Soc. 63 , 437
(1941)]; (3) PH dependence of complex compound formation and (4) determination of the apparent stability constant of complex compounds. Spectral analysis, including visible and ultraviolet spectra, PH determination, and infrared spectrometry were used as additional means to confirm the findings regarding the formation and molecular composition of the 1:1 copper()citrate complex. Here, 1 used as a bactericidal agent or a stabilizer:
Copper complexes are highly soluble, indicating that such complexes are ionic. This fact is further supported by the phenomenon in which a colored band of a complex compound solution moves toward the anode in an electrophoresis experiment. The visible and UV spectra show the formation of a 1:1 compound. The total reaction to form a complex compound of type (B) structure appears to be as follows. (1) (2) K _abs = [Cu-citric acid root ^-2 ] [H ⁺ ]/[Cu
⁺² ] [Citric acid root ^-3 ] K _eff = [Cu-Citric acid root ^-2 ]/[Cu ⁺² ] [
Citric acid group ^-3 ] In this way, instead of only ^the _-COO- group being complexed, the alcohol, -OH, is ionized and included in the coordination bond. They form stable 5- and possibly 6-membered rings. Therefore, the reaction proceeds as OH ^- (base) as the produced H ⁺ is removed as the reaction progresses.
Proceeds to the right (stabilized) by. This results in a very large effective stability constant K _eff . The K _eff for such a reaction depends on the PH, but
It can be related to the absolute stability constant K _abs by the following relationship. K _eff = [Cu citric acid root ⁼ ] / [Cu ⁺⁺ ] [citric acid root ^-3 ] K _abs = [Cu citric acid root ⁼ ] [H ⁺ ] / [Cu ⁺⁺
] [Citric acid radical ^-3 ] K _abs = K _eff · [H ⁺ ] K _abs for a 1:1 complex compound is approximately 9-12
It was found to have a constant value of about 10 ¹³ (strongly complex compound) over the PH range. The apparent value of K _abs is PH7
It decreases rapidly at ~9, and at pH values smaller than about 7,
The complex compound is further reduced to show that it exists in finite concentrations even at pH 3-7. It is believed that another important feature of the complex compounds of the present invention is that they can be used to function as highly effective fungicides. This can be exemplified by the case where the bacteria are grown in a medium having a pH of, for example, about 9 to about 11 and a dialkali monocopper citrate complex compound is introduced. As mentioned above, an alkaline PH environment stabilizes the copper() citrate complex compound. It is hypothesized that free copper ions, by being directly attached to the cell surface, will not pass through the cell membrane at all, or at most, will not pass easily enough to form a complex. Complex compounds, on the other hand, are probably due to (1) their organic nature, which allows them to act as metabolites on which bacterial growth or reproduction depends, or (2) the dianionic nature of complex compounds, which increases their permeability through the bacterial cell wall. It easily crosses cell membranes because of its low charge density. After passing through the cell membrane, the complex will become subject to PH conditions at about position 7. Therefore, after passage, certain complex compounds are very unstable and changeable, and copper ions are easily liberated in large quantities, causing denaturation of cellular proteins or metabolic interference with intracellular biochemical reactions. and kill cells. In contrast, other known complex compounds are rather stable and kinetically inert when passed under such circumstances, binding too tightly even at an intracellular pH of about 7. It cannot be very toxic and would not be effective. The metal complex compounds of the present invention have very unique bactericidal properties compared to conventional compounds. For example, the formation of heavy metals in carboxylic acids is very common. However, with the exception of salts of low molecular weight acids, they are generally insoluble in water. This is cupric citrate () [(Cu ₂ citric acid root) ₂ .
5H ₂ O]. This compound is formed when a strongly basic solution of sodium citrate containing Cu ⁺⁺ is heated. Cupric citrate (2:1 ratio of copper atoms to citrate ions) precipitates out of the solution. This cupric citrate has the following properties: (1) It is insoluble in water (the true total charge of this compound is zero; 2Cu ⁺⁺ and citric acid radical ^-4 ); the reaction is 2Cu ⁺⁺ + citric acid radical ≡ 〓Cu ₂ citric acid root ↓ + H ⁺ moves in the direction completed by the reaction between the generated H ⁺ and OH ^- in a basic medium. (2) The solid color is light green. (3) Elemental analysis demonstrates a Cu:citrate ratio of 2:1. The insolubility of cupric citrate limits the effectiveness of this compound as a bactericidal agent, and its use has been limited until now, even though it has been proposed for pharmaceutical use. Bactericidal activity The following experiments were conducted using conventional cupric citrate (2) against disodium citrate (2) of the present invention.
was carried out to illustrate the bactericidal effect of The following materials, equipment and methods were used. Material 1 Three representative test microorganisms were selected for testing: a. Staphylococcus aureus ATCC #12600, symbol “SA” b. Aerogenous aerial sterilization ATCC #13048, symbol “AA” c. Green-blue Pseudomonas ATCC #10145, The symbols “PA” and “ATCC#” are American Type Culture Collection.
Culture Collection) # is an abbreviation. 2. Trypticase soybean soup, Difco, which is prepared by a specific method by dissolving it in hot water and autoclaving it, and is capable of favorably growing test microorganisms. 3. Macragram for estimating the growth of bacteria in soup. MacLaglan Turbidity Standard. 4 Microporous bacterial filtration device for estimating bacterial growth and the amount of growing microorganisms. 5 Disodium citrate monocopper (),
_{Na2CuC6H4O7.XH2O ,} molecular _weight 297, solid, prepared as previously described, _symbol " _MCC ". 6 Cupric citrate (), Cu ₂ C ₆ H ₄ O ₇・21/
2H ₂ O, molecular weight 360, solid, National
Prepared according to Formulary instructions, symbol “DCC”. 7 Coleman Jr. spectrophotometer for turbidity determination. Here "OD" refers to the optical density measurement and "OS" means the pointer has scaled off due to turbidity. 8 Standard sterile screw cap culture tubes 9 Air bath bacterial incubator, 35°C Method Three control tubes containing 5.0 ml of broth were prepared for each microorganism to be tested.
Each triplicate tube was inoculated with approximately 10 ⁶ microorganisms/ml from the culture. The pH of the culture medium was approximately 7. Two additional spectrophotometer blanks were prepared. MCC and DCC were added to one tube of each set, and the amount of copper was 0.5 mg/. The treatment conditions are outlined in the following table.

Table: Following the direct quantitative and growth tests, all tubes were loosely capped and incubated for 48 hours at 35°C, after which the tests were repeated. The results are shown in the table. In the table, plate number indicates the approximate number of microorganisms, and NIA indicates that it cannot be measured.

[Table] The above test results are for all test microorganisms.
MCC has been shown to have significant bactericidal activity. The reduction in viable microorganisms in the immediate phase about 5 minutes after MCC addition is particularly pronounced. D.C.C.
It is likewise found that although some inhibition of Staphylococcus aureus is somehow observed after 48 hours of incubation, it exhibits very little bactericidal activity, if any at all. Moreover, these tests show that MCC is completely soluble in aqueous solutions and therefore easily dissolved in soup. On the other hand, DCC is insoluble in aqueous media;
A cloud-like suspension forms, which settles completely within a few minutes. Therefore, before reading OD (optical density), DCC
The containing tube is allowed to settle until the reading becomes constant so that the measured turbidity is actually due to bacterial particles.
Although the turbidity test is a fairly accurate quantitative method, it does not indicate the actual growth of microorganisms. Therefore, it is necessary to use biological quantitative methods to determine growth as well as to ascertain the actual number of growing microorganisms. In addition to the above, the bactericidal activity of dialkali copper citrate () has been confirmed by its toxic and growth-inhibiting effects on the following microorganisms in oil emulsion media used as coolants in various mechanical operations: Ta. In this case, the pH of the coolant bath and liquid was about 9 to about 10. Such manufacturing coolant compositions are disclosed in U.S. Pat. No. 3,244,630 and by the American Society of Tall Engineers “American
Society of Tool Engineers” Thor Engineer’s Handbook “Tool Engineer’s”
Aerobacterium aerogenes, 1st edition, 1953, pages 357 et seq., which are hereby incorporated by reference.
aerogenes) Aspergillus niger
niger) Bacteroides Bacillus subtilis Candida albicans Citrobacter Enterobacter Serratia
cerratia) Enterobacter cloake (Enterobacter
cloacae) Escherichia coli Klebsiella Aerobacterium
Aerobacter) Neisseria cataloharis (Neisseria
catarrhalis) Proteus (Providence group) [Proteus
(Providence Group) Proteus mirabilis
mirabilis) Proteus morgani Proteus rettgeri Proteus vulgaris Pseudomonas aeruginosa Pseudomonas fluorescens Salmonella species
species) Staphylococcus albus Staphylococcus aureus Staphylococcus epidermidis Streptococcus fecalis Streptococcus viridans Effective as above for bactericidal activity The properties were determined in industrial coolant liquids in which the listed microorganisms are known to thrive. Importantly, even at such high PH's as required for coolant liquid performance, di-alkali cupric citrate () is extremely effective.
Furthermore, for example, it will be seen that approximately 100 times more free copper is available at PH 8.5 than at PH 9.5 with respect to the dissociation curves in the attached figure. Similarly, as the pH drops below 8.5, even more toxic copper ions are liberated. Such tests demonstrate the suitability of the fungicides of the invention. Additionally, commercial coolant baths have been tested over several months and it has been found that the disinfectant of the present invention undergoes a decrease in activity due to the controlled release of copper ions on demand in the coolant bath. It has been confirmed that it is effective over a fairly long period of several weeks. Antibacterial activity of various metal complex compounds (1) Escherichia coli (ATCC#25922),
Enterobacter cloacae (ATCC #23355),
Cultures were prepared by culturing Staphylococcus aureus (ATCC #25923) and Streptococcus pyogenes in sterile Tryptocase soybean medium for 24 hours each. (2) 15mM solutions of various metal complex compounds shown below were prepared. (a) Disodium citrate monocopper (b) Disodium citrate monomercury (c) Disodium citrate monocobalt (d) Disodium citrate mononickel (e) Disodium citrate monozinc (f) Mercaptosuccine Monosodium acid, monocopper (g) Monosodium mercaptosuccinate, monozinc (h) Monosodium tartrate, monocopper (i) Monosodium tartrate, monozinc (j) Monosodium tartrate, monomercury The pH of each solution is 7.0 ± before use. Adjusted to 0.5. (3) 1 ml of each of the solutions in (2) above and 1 ml of sterile distilled water were respectively added to tubes containing 5 ml of Tryptocase soybean medium. 0.1 ml of each culture from (1) above was added to the obtained tube. (4) The tubes were mixed well and the absorbance (A450) of each tube was measured against blank (water).
Remove the tube cap and heat the tube to 37℃.
Incubated with. A450 was measured after 24 hours, and the change in absorbance (ΔA450) was determined. The bacterial growth rate (%) relative to the blank after 24 hours is shown in the table.

【table】

[Table] As is clear from the table, various metal complex compounds containing α- or β-hydroxy or mercapto aliphatic di- or tricarboxylic acids and heavy metal ions in a molar ratio of 1:1 have excellent antibacterial activity. As mentioned above, the metal complex compound can be used in aqueous solution or solid form. Bactericidal activity can be obtained by adding an effective amount of either form. It is not necessary to remove other by-product salts from the prepared complexes to obtain further activity. However, the by-products water and salts as described in the above process can surprisingly also be removed to form a solid complex compound of the concentrate. Several objectives can be achieved through this. For example, to remove harmful contaminants due to excessive salt concentrations or corrosion problems when using complex compounds in practical applications, or to make it possible to prepare solutions with higher concentrations of active ingredients, thereby making it easier to store them. Obvious advantages in industrial applications can be obtained in terms of reduced volumes and thus reduced shipping and storage costs. It is also desirable to prepare complexes as pure as possible for use as other preservatives, food disinfectants, other bactericides, sporicides, virucides or disinfectants. Other modifications of the invention and its embodiments will become apparent from a review of the present description, examples and presently preferred form without departing from the spirit and scope of the invention.

[Brief explanation of the drawing]

Figure 1 plots the relationship between the negative logarithm of the metal ion (Cu ⁺⁺ ) concentration versus the negative logarithm of the hydrogen ion concentration (i.e., pM versus PH) in the case of disodium copper citrate (). This shows the proton-induced dissociation of the complex compound (solid line). On the other hand, the dotted line is Cu
It shows the effect of PH on EDTA complex compounds.
Figure 2 shows the pM of monosodium-copper tartrate ().
Figure 3 shows the relationship between pM and PH of monosodium mercaptosuccinate monozinc.

Claims (1)

[Scope of Claims] 1. Consisting of a metal complex compound of a heavy metal ion and a polyfunctional organic ligand, the metal complex compound having a molar ratio of heavy metal ion to polyfunctional organic ligand of 1:1, The polyfunctional organic ligand is selected from the group consisting of α- or β-hydroxy or mercaptoaliphatic dicarboxylic acids and α- or β-hydroxy or mercaptoaliphatic tricarboxylic acids, and the metal complex compound has a metal ion concentration of Plotting the negative logarithm versus the negative logarithm of the hydrogen ion concentration on a rectangular coordinate system can be represented by an S-shaped curve. A fungicide consisting of a metal complex compound. 2. The disinfectant according to item 1, wherein the PH is within the range of about 10 ^-4 to about 10 ^-9 moles of hydrogen ions. 3. The disinfectant according to item 1, wherein the PH is in the range of about 10 ^-7 to about 10 ^-9 mol/hydrogen ion. 4. The controlled release of the metal ion is such that about 10% to about 0.1% of the metal in the complex is released over a pH range of about 7 to about 9. Fungicide. 5. The disinfectant according to item 1 above, wherein the metal complex compound is a complex compound of a divalent metal ion and a polyfunctional organic ligand in a molar ratio of 1:1. 6. The disinfectant according to item 1 above, wherein the metal complex compound is dialkali monocopper citrate (). 7 Introducing a bactericidal effective amount of a metal complex compound of a metal ion and a polyfunctional organic ligand into a medium that supports the growth of bacteria, whereby the molar ratio of the metal ion to the polyfunctional organic ligand is 1:1, and the polyfunctional organic ligand is selected from the group consisting of α- or β-hydroxy or mercapto aliphatic dicarboxylic acids and α- or β-hydroxy or mercapto aliphatic tricarboxylic acids; However, when the negative logarithm of the metal ion concentration versus the negative logarithm of the hydrogen ion concentration is plotted on rectangular coordinates, the dissociation caused by the aqueous protons is represented by an S-shaped curve, and the bacteria in the medium A method of obtaining bactericidal activity in a bacterial growth medium that has dissociative properties that cause controlled release of metal ions at a pH that allows growth. 8. The method of item 7 above, wherein the medium has a PH of about 3 to about 12. 9. The method of item 8 above, wherein the PH is within the range of about 4 to about 9. 10. The method according to item 7 above, wherein the PH is alkaline. 11. The method of paragraph 10, wherein the PH is within the range of about 9 to about 12. 12. The method according to item 11, wherein the complex compound is a dialkali monometal chelate of α-hydroxy aliphatic tricarboxylic acid. 13 The chelate is dialkali copper citrate ()
The method according to item 11 above. 14. The method according to item 13 above, wherein the chelate is an aqueous mixture. 15. The method according to item 13 above, wherein the chelate is a solid. 16. The method according to item 7 above, by introducing a bactericidal effective amount of dialkali monocopper citrate () into the medium that supports the growth of bacteria. 17. The method according to item 16 above, wherein the medium has an alkaline PH. 18. The method of item 17, wherein the pH of the medium is within the range of about 9 to about 12. 19. The method of item 16, wherein the medium has a pH range of about 7 to about 9, and about 10% to about 0.1% of the copper ions in the complex are liberated within that range.