WO2009087395A1

WO2009087395A1 - Weight reducing compounds

Info

Publication number: WO2009087395A1
Application number: PCT/GB2009/000064
Authority: WO
Inventors: Roger David Waigh; Alan Lang Harvey; Mark Hugh Mooney; Geoffrey Coxon
Original assignee: University Of Strathclyde
Priority date: 2008-01-10
Filing date: 2009-01-09
Publication date: 2009-07-16
Also published as: GB0800383D0

Abstract

The present invention relates to compounds which find use as weight reducing agents, and find use in treating obesity and/or excess adiposity.

Description

WEIGHT REDUCING COMPOUNDS

Introduction

Background

Dimethylallylguanidine, also known as galegine, was first isolated from the plant Galega officinalis in the late 1800s. The plant has a long history of use as an antidiabetic and galegine itself was used for a short time as a hypoglycemic. Research in the 1950s resulted in the discovery of biguanides, rather than guanidines. These are known as the ' formin ' class of agents, and one of these, metformin, is still used for the treatment of type 2 diabetes .

galegine

metformin phenformin

More recently, international patent application, with publication number WO 96/36325, describes an unexpected weight reduction effect when galegine is administered to a mammal, and describes a general chemical structure encompassing galegine and analogue compounds of interest, together with specifically described analogue compounds.

International patent application, with publication number WO 93/03714 discloses two lists of a number of individual compounds. The first list of compounds are said to be useful in treating or preventing non-insulin dependent diabetes mellitus (NIDDM) , with the suggestion that those compounds may be useful for other indications, including hyperglycemia, impaired glucose tolerance, hyperinsulinemia, excess adiposity and/or hyperlipidemia . No firm conclusions are drawn however, and no indication of a structure-activity relationship between the compounds and the listed conditions is provided and does not appear derivable from the information provided. Also, it is clear that a compound which is said to be useful for treating NIDDM or which is said to have hypoglycemic activity does not necessarily display weight reducing properties and would not be automatically considered as a weight reducing candidate. The second list of compounds are said to be useful in treating or preventing excess adiposity or obesity, however, again no firm conclusions are drawn and no common structure-activity relationship appears derivable from the information provided.

The Applicant of the present invention has now unexpectedly found that a select group of compounds provide improved weight reducing effects in mammals.

Summary of the Invention

According to a first aspect of the present invention there is provided a compound according to formula (I) , or a physiologically acceptable salt thereof, for weight reduction:

(D wherein,

R¹, R², R³ and R⁴ may be the same or different and are independently selected from H or Ci-C₆ alkyl;

R⁵ and R⁶ are independently selected at each position H, C_x-C₆ alkyl or O-alkyl CF₃ or Hal or R⁵ and R⁶ are adjacent and together form a five or six membered hydrocarbon or heterocylic ring,

R⁷ is H or Ci-C₆ alkyl,

Hal is selected from F, Cl, Br and I; and n is 0 or 1; and excluding the following compounds and salts thereof: i) R⁵ is H, n is 0, R¹ and R² are H, ii) R⁵ is H, n is 1, R¹ and R² are H, R³ and R⁴ are methyl, iii) R⁵ is H, n is 1, R¹, R², R³ and R⁴ are all H, and iv) R⁵ is Hal which is Cl, n is 1, R¹, R², R³ and R⁴ are all H.

Preferably where R⁵ and R⁶ together form a ring, this

is phenyl or

Preferably R⁷ is H or methyl.

Preferred compounds for the stated use include those of formula (I) in which R⁵ is Hal and n is 0.

Particularly preferred compounds of formula (I) for the stated use are those in which R⁵ is Hal, n is 0 and R¹, R², R³ and R⁴ are all H.

More preferred are those compounds in which Hal is chlorine or bromine, for example, most preferred are those compounds of formula (I) in which R⁵ is chlorine or bromine, n is 0 and R¹, R², R³ and R⁴ are all H.

Other preferred compounds for the stated use include those of formula (I) in which R⁵ is H and n is 1.

Particularly preferred compounds in which R⁵ is H are those compounds of formula (I) in which n is 1, R¹, R², and R³ are all H, and R⁴ is Ci-C₆ alkyl. In this preferment, R⁴ is most preferably methyl or ethyl, particularly methyl.

The Cχ-Cg alkyl group includes methyl, ethyl, propyl, butyl, pentyl and hexyl, and includes geometric isomers and branched and cyclic versions as appropriate. For example, included are iso-propyl, sec-butyl, tert-butyl and cyclo-hexyl.

Preferably, the Ci-C₆ alkyl group is a Ci-C₄ alkyl group. The Ci-C₆ alkyl group can be optionally substituted, e.g. by carboxy, hydroxyl, substituted or unsubstituted amino, substituted or unsubstituted amide, nitro, thio, formyl, cyano, carbamoyl, halo (e.g. fluoro, chloro, bromo or iodo) , an ester, a ketone, -S(O)NR¹²R¹³ or -S(O)R¹⁴, wherein R¹², R¹³ and R¹⁴ each independently are Ci-C₆ alkyl.

The compounds according to formula (I) which are useful as described herein may be presented as a physiologically acceptable salt, ester or other physiologically functional derivative thereof, and the present invention also relates to the uses of those compounds of formula (I) for the preparation of a medicament for weight reduction.

The present invention also provides novel compounds. According to a second aspect of the present invention, there is provided a compound according to formula (II), or a physiologically acceptable salt thereof:

(II) wherein,

R¹, R², R³ and R⁴ may be the same or different and are independently selected from H or Ci-C₆ alkyl; R⁵ and R⁶ are independently selected at each position H, Ci-C₆ alkyl or O-alkyl CF₃ or Hal or R⁵ and R⁶ are adjacent and together form a five or six membered hydrocarbon or heterocylic ring,

R⁷ is H or C₁-C₆ alkyl, Hal is selected from F, Cl, Br and I; and n is 0 or 1; and excluding the following compounds and salts thereof: i) R⁵ is H, n is 0, R¹ is H and R² is H, methyl or ethyl, ii) R⁵ is H, n is 1, R¹ and R² are H, R³ and R⁴ are methyl, iii) R⁵ is H, n is 1, R¹, R², R³ and R⁴ are all H, iv) R⁵ is Hal and is Cl, n is 1, R¹, R², R³ and R⁴ are all H, and iv) Hal is F, Cl or Br, n is 0 and R¹ and R² are H.

Preferred compounds include all those described above in relation to the stated use, excluding the compounds described in the above statements i) - ii) . According to a third aspect of the present invention, there is provided a pharmaceutical composition comprising a compound according to formula (I) as described hereinbefore, together with a pharmaceutically acceptable carrier therefor. According to a fourth aspect of the present invention, there is provided use of a compound as described according to the first aspect e.g. according to formula (I) , for the preparation of a medicament for weight reduction. The weight reduction obtainable by means of the present invention includes both therapeutic and cosmetic weight reduction, and finds use in treating obesity and/or excess adiposity. The weight reduction in accordance with the present invention may be applied to mammals which are obese through dietary intake or which are genetically predisposed to obesity. It is noted that an obese phenotype may be demonstrated as a consequence of failure to produce leptin, whereas diet-induced obesity is more typical of the presence of hyperleptinaemina and where excessive calorie intake interacts with particular genetic backgrounds to produce obesity.

Subjects include non-human animals, e.g. mammals especially domestic companion animals, such as dogs, cats rabbits and the like, and humans.

The compounds of the present invention may also be used to provide a hypoglycaemic effect.

According to a fifth aspect of the present invention there is provided a method of weight reduction, the method comprising applying an effective amount of a compound according to the first or second aspects e.g. according to formulae (I) or (II) as described hereinbefore to an individual in need thereof. Examples of physiologically acceptable salts of the compounds according to the invention include acid addition salts formed with organic carboxylic acids such as acetic, lactic, tartaric, maleic, citric, pyruvic, oxalic, fumaric, oxaloacetic, isethionic, lactobionic and succinic acids; organic sulfonic acids such as methanesulfonic, ethanesulfonic, benzenesulfonic and p-toluenesulfonic acids and inorganic acids such as hydrochloric, sulfuric, phosphoric and sulfamic acids. Hydrogen sulfate salts are also included. The compounds described herein include a guanidine functional group which causes the compounds to become very strong bases and which may react with carbon dioxide (e.g. in the atmosphere) to form a molecule of a carbamic acid for each molecule of compound which then reacts with a second molecule of compound to form a salt. Such salts are also included within the term physiologically acceptable salts.

The present invention also includes physiologically functional derivatives of the described compounds.

Physiologically functional derivatives of compounds of the present invention are derivatives which can be converted in the body into the parent compound. Such physiologically functional derivatives may also be referred to as "pro-drugs" or "bioprecursors" . Physiologically functional derivatives of compounds of the present invention include in vivo hydrolysable esters and amides .

It will be appreciated that some of the compounds of the present invention may exist in various stereoisomeric forms and the compounds of the present invention as hereinbefore defined include all stereoisomeric forms and mixtures thereof, including enantiomers and racemic mixtures. The present invention includes within its scope the use of any such stereoisomeric forms or mixtures of stereoisomers, including the individual enantiomers of the compounds of formulae (I) and (II) as well as wholly or partially racemic mixtures of such enantiomers.

A preferred configuration for the compounds according to formula (I) is that represented by formula (III) :

(III) wherein R⁵ is Hal which is Cl or Br. An alternative preferred compound of the present invention has the formula (IV) :

wherein, R⁴ is C₁-C₆ alkyl, preferably Ci-C₄ alkyl, most preferably methyl or ethyl, typically methyl.

These compounds according to formula (IV) , in particular when R⁴ is methyl, are believed to be novel and as such form a further feature of this invention.

It will be appreciated that the absolute stereochemistry about the carbon atom to which R⁴ is attached may be S- or R-, and those compounds may be provided as enantiomers or racemic mixtures, or mixtures containing unequal amounts of the S- or R- forms.

The compounds of the present invention may be prepared using reagents and techniques readily available in the art and as described hereinafter. Novel intermediate compounds in the synthetic route for preparation of the compounds of the present invention may be important molecules for general application for the preparation of the molecules of the present invention.

Accordingly, the present invention extends to include those novel intermediate compounds.

The present invention further provides a treatment or prophylaxis of a disease, pathology or condition recited herein comprising administering a compound recited herein to a patient in need thereof.

The patient is typically an animal, e.g a mammal, especially a human.

For use according to the present invention, the compounds or physiologically acceptable salt, ester or other physiologically functional derivative thereof described herein may be presented as a pharmaceutical formulation, comprising the compound or physiologically acceptable salt, ester or other physiologically functional derivative thereof, together with one or more pharmaceutically acceptable carriers therefore and optionally other therapeutic and/or prophylactic ingredients. The carrier (s) must be acceptable in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. The dose of compound described herein shall be determined by the skilled practitioner in accordance with well established pharmacological principles. A typical dose may be administered orally in the food of the recipient thereof, in amounts such as from about 1 mmol to about 25 mmol of compound per kg of food. Preferable amounts being from about 2.5 mmol to about 10 mmol per kg of food, most preferably, about 3 mmol to about 5 mmol per kg of food. A desirable amount is 3.25 - 3.75 mmol per kg of food. Typically, the compounds may be added to a recipient animal in an amount of 0.05 - 5 mmol/kg body weight/day, such as 0.1 - 2 mmol/kg body weight/day.

Pharmaceutical formulations include those suitable for oral, topical (including dermal, buccal and sublingual) , rectal or parenteral (including subcutaneous, intradermal, intramuscular and intravenous) , nasal and pulmonary administration e.g., by inhalation. The formulation may, where appropriate, be conveniently presented in discrete dosage units and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing into association an active compound with liquid carriers or finely divided solid carriers or both and then, if necessary, shaping the product into the desired formulation. Pharmaceutical formulations suitable for oral administration wherein the carrier is a solid are most preferably presented as unit dose formulations such as boluses, capsules or tablets each containing a predetermined amount of active compound. A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine an active compound in a free-flowing form such as a powder or granules optionally mixed with a binder, lubricant, inert diluent, lubricating agent, surface-active agent or dispersing agent. Moulded tablets may be made by moulding an active compound with an inert liquid diluent. Tablets may be optionally coated and, if uncoated, may optionally be scored. Capsules may be prepared by filling an active compound, either alone or in admixture with one or more accessory ingredients, into the capsule shells and then sealing them in the usual manner. Cachets are analogous to capsules wherein an active compound together with any accessory ingredient (s) is sealed in a rice paper envelope. An active compound may also be formulated as dispersible granules, which may for example be suspended in water before administration, or sprinkled on food. The granules may be packaged, e.g., in a sachet. Formulations suitable for oral administration wherein the carrier is a liquid may be presented as a solution or a suspension in an aqueous or non-aqueous liquid, or as an oil-in-water liquid emulsion.

Formulations for oral administration include controlled release dosage forms, e.g., tablets wherein an active compound is formulated in an appropriate release - controlling matrix, or is coated with a suitable release - controlling film. Such formulations may be particularly convenient for prophylactic use. Pharmaceutical formulations suitable for rectal administration wherein the carrier is a solid are most preferably presented as unit dose suppositories. Suitable carriers include cocoa butter and other materials commonly used in the art. The suppositories may be conveniently formed by admixture of an active compound with the softened or melted carrier (s) followed by chilling and shaping in moulds.

Pharmaceutical formulations suitable for parenteral administration include sterile solutions or suspensions of an active compound in aqueous or oleaginous vehicles.

Injectible preparations may be adapted for bolus injection or continuous infusion. Such preparations are conveniently presented in unit dose or multi-dose containers which are sealed after introduction of the formulation until required for use. Alternatively, an active compound may be in powder form which is constituted with a suitable vehicle, such as sterile, pyrogen-free water, before use. An active compound may also be formulated as long- acting depot preparations, which may be administered by intramuscular injection or by implantation, e.g. subcutaneously or intramuscularly. Depot preparations may include, for example, suitable polymeric or hydrophobic materials, or ion-exchange resins. Such long- acting formulations are particularly convenient for prophylactic use.

Formulations suitable for pulmonary administration via the buccal cavity are presented such that particles containing an active compound and desirably having a diameter in the range of 0.5 to 7 microns are delivered in the bronchial tree of the recipient.

As one possibility such formulations are in the form of finely comminuted powders^' which may conveniently be presented either in a pierceable capsule, suitably of, for example, gelatin, for use in an inhalation device, or alternatively as a self-propelling formulation comprising an active compound, a suitable liquid or gaseous propellant and optionally other ingredients such as a surfactant and/or a solid diluent. Suitable liquid propellants include propane and the chlorofluorocarbons, and suitable gaseous propellants include carbon dioxide. Self-propelling formulations may also be employed wherein an active compound is dispensed in the form of droplets of solution or suspension.

Such self-propelling formulations are analogous to those known in the art and may be prepared by established procedures. Suitably they are presented in a container provided with either a manually-operable or automatically functioning valve having the desired spray characteristics; advantageously the valve is of a metered type delivering a fixed volume, for example, 25 to 100 microlitres, upon each operation thereof.

As a further possibility an active compound may be in the form of a solution or suspension for use in an atomizer or nebuliser whereby an accelerated airstream or ultrasonic agitation is employed to produce a fine droplet mist for inhalation.

Formulations suitable for nasal administration include preparations generally similar to those described above for pulmonary administration. When dispensed such formulations should desirably have a particle diameter in the range 10 to 200 microns to enable retention in the nasal cavity; this may be achieved by, as appropriate, use of a powder of a suitable particle size or choice of an appropriate valve. Other suitable formulations include coarse powders having a particle diameter in the range 20 to 500 microns, for administration by rapid inhalation through the nasal passage from a container held close up to the nose, and nasal drops comprising 0.2 to 5% w/v of an active compound in aqueous or oily solution or suspension.

It should be understood that in addition to the aforementioned carrier ingredients the pharmaceutical formulations described above may include, an appropriate one or more additional carrier ingredients such as diluents, buffers, flavouring agents, binders, surface active agents, thickeners, lubricants, preservatives (including anti-oxidants) and the like, and substances included for the purpose of rendering the formulation isotonic with the blood of the intended recipient.

Pharmaceutically acceptable carriers are well known to those skilled in the art and include, but are not limited to, 0.1 M and preferably 0.05 M phosphate buffer or 0.8% saline. Additionally, such pharmaceutically acceptable carriers may be aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of nonaqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media. Parenteral vehicles include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's or fixed oils. Preservatives and other additives may also be present, such as, for example, antimicrobials, antioxidants, chelating agents, inert gases and the like.

Therapeutic formulations for veterinary use may conveniently be in either powder or liquid concentrate form. In accordance with standard veterinary formulation practice, conventional water soluble excipients, such as lactose or sucrose, may be incorporated in the powders to improve their physical properties. Thus particularly suitable powders of this invention comprise 50 to 100% w/w and preferably 60 to 80% w/w of the active ingredient (s) and 0 to 50% w/w and preferably 20 to 40% w/w of conventional veterinary excipients. These powders may either be added to animal feedstuffs, for example by way of an intermediate premix, or diluted in animal drinking water.

Liquid concentrates of this invention suitably contain the compound or a derivative or salt thereof and may optionally include a veterinarily acceptable water- miscible solvent, for example polyethylene glycol, propylene glycol, glycerol, glycerol formal or such a solvent mixed with up to 30% v/v of ethanol. The liquid concentrates may be administered to the drinking water of animals .

The present invention will now be described with reference to the following non-limiting examples.

Detailed Description

Compound synthesis: All reagents and solvents were of commercial quality; solvents were dried according to standard procedures when deemed necessary. IR spectra were recorded with a Mattson Genesis Series FTIR spectrometer, solid samples were pressed potassium bromide (KBr) discs and liquid samples were films in sodium chloride (NaCI) discs. Wave frequencies, v_max (cm¹) are quoted for appropriate functional groups. Melting points (Mp) were determined on a Stuart Scientific Melting Point Apparatus SMPI and are in ⁰C. ¹H and ¹³C NMR spectra were recorded on JEOL EX-270 (270 MHz) spectrometer. The deuterated solvent used is specified for each compound, chemical shifts are expressed in parts per million. Reactions and column chromatographic separations were followed by thin-layer chromatography using silica gel (with 254 nm fluorescent indicator) . Samples were submitted for elemental analysis on a Perkin Elmer 2400 Analyser. C, H and N determined simultaneously, halogens and sulfur separately after recrystallisation of the organic salts from water.

1- (3-Methylbut-2-enyl) guanidine hemisulfate (galegine) for reference purposes and general procedure for synthesis of guanidine hemisulfates :

A mixture of 4-bromo-2-methyl-2-butene (19.4g, 1.0 eq, 130 mmol) and potassium phthalimide (29.8g, 1.2 eg, 161 mmol) were suspended in DMF (200 ml) and stirred at 12O⁰C for 1 hour before heating to 160⁰C and stirring for a further 18 hours. The mixture was poured over ice and washed with dichloromethane (5 x 50 ml) , the organic phases separated and combined before washing with sodium hydroxide solution (0.1N) (2 x 100ml) and water (2 x 50ml) . The organic extracts were' separated, dried over anhydrous magnesium sulfate, filtered and concentrated to leave a crude solid which was crystallised from cold ethanol to give the intermediate 2- (3-methylbut-2- enyl) isoindoline-1 ,3-dione (25.6g, 93%) as a white solid. Mp: 100-101 ⁰C. ¹H NMR (D₂O) : δ 7.88-7.91 (m, 2 x CH, 2H), 7.61-7.70 (m, 2 x CH, 2H), 5.31 (m, C-CH, IH), 4.31 (d, CH₂, 2H, J=7.2Hz), 1.70 (s, CH₃, 3H), 1.62 (s, CH₃, 3H) . IR (cm^""1) (KBr) 3090 (m) , 3040 (m) , 3001 (m) , 2971 (s) , 1763 (s), 1730 (s) . Anal. (C₆H₁₅N₃SO₄) : C, H, N.

A mixture of 2- (3-methylbut-2-enyl) isoindoline-1, 3- dione (1Og, 1.0 eq, 46.6 mmol), ethanol (100 ml) and hydrazine hydrate (85%) (2.9ml, 1.2eq, 51.1 mmol) were stirred under reflux for 1 hour, cooled, hydrochloric acid (IM) (5.2ml, 1.2 eq, 51.1 mmol) added and refluxed for a further 1 hour. The mixture was allowed to cool, filtered and the residue washed with cold water (100 ml) before reducing the filtrate under vacuum to give the intermediate 3-methylbut-2-en-l~amine hydrochloride (4.4g, 78%) as a white solid. Mp: 95-97 ⁰C. ¹H NMR (D₂O): δ 6.75 (brs, NH, IH), 6.55 (brs, NH₂, 2H), 5.16 (t, CH, IH, J=6.3 Hz), 3.68 (d, NCH₂, 2H, J6.3Hz), 1.71 (s, CH₃, 3H), 1.63 (s, CH₃, 3H) -¹³C NMR (D₂O) : δ. IR (cm¹) (KBr) 3332-3216

(br), 2944 (m) , 2884 (m) , 2156 (m) , 1649 (s) . Anal. (C₅Hi₂NCl) : C, H, N.

2-Methylthiopseudourea sulfate (6.95g, 1.0 eq, 150 mmol) and 3-methylbut-2-en-l-amine (9.1g, 2.0 eq, 100 mmol) were dissolved in water (100 ml) and ethanol (100 ml) . The mixture was stirred at reflux for 18 hours, connected to a series of bleach traps, before cooling and reducing under vacuum to give a white crude solid. The compound was suspended in water (30 ml) and heated until it barely dissolved before allowing to slowly cool upon which a white solid began to form. After allowing the formation of the solid to continue overnight, it was collected by filtration and dried in the oven to give galegine (5.4g, 62%) as a white solid. Mp: 216-218 ⁰C (dec) . Lit. 214-216 ⁰C (dec) (Desvages, G.; Olomucki, M. Research on the derivatives of guanidines from Galega officinalis . L: galegine and hydroxygalegine, Bull. Soc. Chim. Fr. 1969, 3229-3232.). ¹H NMR (D₂O) : δ 5.32 (m, C=CH, IH), 3.78 (d, CH₂, 2H, J6.7Hz), 1.81 (s, CH₃, 3H), 1.72 (s, CH₃, 3H) . IR (cm^"1) (KBr) 3500-3100 (br) , 2974 (s), 2922 (s), 2784 (s) . Anal. (Ci₂H₂₈N₆O₄S) : C, H, N.

Preparation of 1- (4-chlorobenzyl) guanidine hemisulfate (GDC 151) as a general procedure

2-Methylthiopseudourea sulfate (8.2 g, 1.0 eq, 58.94 mmol) and 4-chlorobenzylamine (16.6 g, 2.0 eq, 117.88 mmol) were dissolved in water (100 ml) and ethanol

(100ml) . The mixture was stirred at reflux for 18 hours, connected to a series of bleach traps, before cooling and reducing under vacuum to give a white crude solid. The compound was suspended in water (200 ml) and heated until it barely dissolved before allowing it to slowly cool upon which a white solid began to form. After allowing the formation of the solid to continue overnight, it was collected by filtration and dried in the oven to give 1- (4-chlorobenzyl) guanidine hemi sulfate (8.91 g, 65 %) as a white solid. MPt 234-235 ⁰C IR (KBr, cm^"1) 3450 (br) , 1669 (S), 1150 (S) . δ_H(D₂O) 7.75-7.65 (m, 4 x CH, 4H), 4.72 (s, NCH₂, 2H) . δc(D₂O:CD₃OD) 158.3 (C=NH), 137.5(CHCl), 35.9, 131.6, 131.3 46.6 (NCH₂) .

CHN Anal. CaIc. for C₁6H₂2N₆O4SCI₂ requires C, 41.29; H, 4.73; N, 18.06; S, 6.88. Found C, 41.22; H, 4.69; N, 17.84; S, 7.11.

1-Phenethylguanidine hemisulfate (GDC 44)

Using the general procedure 1-phenethylguanidine hemisulfate (1.4g, 25%) was obtained as a white solid.

MPt 164-170 ⁰C.

IR (KBr, can^"1) 3358 (br) , 3278 (m) , 2923 (m) , 2934 (m) ,

1653 (s) . δ_H (D₂O) 7.61-7.21 (m, 5 x CH, 5H), 3.44 (t, CH₂, 2H,

J=6.8Hz), 2.85 (t, CH₂, 2H, J=6.8Hz) . δ_c(D₂O:CD₃OD) 157.8 (C=NH), 129.7, 129.6, 127.6, 43.1

(NCH₂), 35.0 (CH₂).

CHN Anal. CaIc. for C₁₈H₂₈N₆O₄S requires C, 50.94; H, 6.60; N, 19.81; S, 7.54. Found C, 33.48; H, 6.71; N, 12.69; S,

9.00. 1- (2-Methoxybenzyl) guanidine hemisulfate (GDC 68)

Using the general procedure, l-(2- Methoxybenzyl) guanidine hemisulfate (625mg, 51%) was obtained as a white solid.

MPt 205-209 ⁰C.

IR (KBr, cm^"1) 3442 (m) , 3351 (br) , 3228 (br) , 3163 (s) ,

1639 (s) , 1183 (s) . δ_H (D₂O) 7.94-7.72 (m, 2 x CH, 2H) , 7.35 (m, 2 x CH, 2H) ,

4.78 (s, NCH₂, 2H) , 4.25 (s, OCH₃, 3H) . δ_c(D₂O:CD₃OD) 157.9 (C=NH) , 131.47, 130.9, 125.1, 122.1,

112.5, 56.4 (OCH₃) , 45.4 (NCH₂) .

CHN Anal. CaIc. for Ci₈H₂₈N₆O₄S, H₂O requires C, 45.57; H, 6.33; N, 17.72; S, 6.75. Found C, 45.78; H, 6.08; N,

17.64; S, 6.61.

1- (3 , 4-Dichlorobenzyl) guanidine hemisulfate (GDC 88)

Using the general procedure, l- (3,4- dichlorobenzyl) guanidine hemisulfate (2.1g, 53%) was obtained as a white solid. MPt 242-244 ⁰C.

IR (KBr, cπf —1^x) 3462 (m) , 3321 (br) , 3143 (br) 2920 (w) , 1669 (s) , 1120 (s) .

SH (D₂O) 7.50 (m, 2 x CH, 2H) , 7.29 (m, I x CH, IH) , 4.40 (s, NCH₂, 2H.

CHN Anal. CaIc. for Ci₆H₂₀N₆O₄Cl₄S, H₂O requires C, 34.78; H, 3.98; N, 15.21; S, 5.80; Cl, 25.72. Found C, 35.01; H, 3.86; N, 15.20; S, 6.19; Cl, 25.62. δ_c(D₂O:CD₃OD) 158.7 (C=NH) , 141.3, 133.6, 131.1, 130.1, 128.9, 126.3, 41.2 (NCH₂) .

(±)-l- (2-phenylpropyl)guanidine hemisulfate (GDC 96)

Using the general procedure, (+)-l- (2- phenylpropyl) guanidine hemisulfate (2.1g, 64%) was obtained as a white solid.

MPt 223-226 ⁰C.

IR (KBr, cm^"1) 3341 (br) , 3160 (br) , 2968 (w) , 1663 (s) ,

1117 (s) . δH (D₂O) 7.31-7.22 (m, 5 x CH, 5) , 3.24 (m, NCH₂, 2H) , 2.98 (m, CH, IH) , 1.31 (d, CH₃, 3H, J=6.9Hz) . δ_c(D₂O:CD₃OD) 157.4 (C=NH) , 144.3, 131.1, 131.0, 128.6,

49.6 (NCH) , 41.3, 19.4.

CHN Anal. CaIc. for C₂₀H₃₂N₆O₄S, 2H₂O requires C, 49.18; H,

7.38; N, 17.21; S, 6.56. Found C, 49.05; H, 7.66; N, 17.01; S, 6.78.

1-benzyl-1-methyl guanidine hemisulfate (GDC 101)

Using the general procedure, 1-benzyl-l-methyl guanidine hemisulfate (2.5, 45%) was obtained as a white solid.

MPt 154-156 ⁰C.

IR (KBr, cm^"1) 3354 (br) , 3162 (br) , 2947 (m) , 2823 (m) , 1664 (s) , 1118 (s) . δ_H (D₂O) 7.61-7.36 (m, 2 x CH, 2H), 7.31 (m, 2 x CH, 2H),

4.81 (s, NCH₂, 2H), 3.0 (s, NCH₃, 3H) . δ_c(D₂O:CD₃OD) 158.2 (C=NH) , 137.7, 130.6, 129.4, 128.3,

54.7 (NCH₂) , 37.4 (NCH₃) .

CHN Anal. CaIc. for C₁₆H₂₈N₆O₄S requires C, 50.94; H, 6.60; N, 19.81; S, 7.54. Found C, 41.05; H, 6.49; N, 21.15; S, 9.71.

1- (3 , 4-Methylenedioxybenzyl) guanidine hemi sulfate (GDC 140)

Using the general procedure, l-(3,4- methylenedioxybenzyl) guanidine hemisulfate (2.4g, 38%) was obtained as a white solid.

MPt 264-268 ⁰C.

IR (KBr, cm^"1) 3414 (m) , 3118 (br) , 3011 (m) , 2926 (w) , 1632 (s) , 1149 (s) . δ_H (D₂O) 7.21 (m, 3 x CH, 3H) , 6.28 (s, OCH₂, 2H) , 4.61 (s,

NCH₂, 2H) . δ_c (D₂O .-CD₃OD) 158.6 (C=NH) , 149.7, 149.0, 131.5, 122.4,

109.9, 109.4, 102.9, 46.3 (NCH₂) . CHN Anal. CaIc. for C₁₈H₂₄N₆O₈S requires C, 44.62; H, 4.95;

N, 17.22; S, 6.43. Found C, 44.83; H, 4.65; N, 17.35; S,

6.61.

1- (4-Fluorobenzyl) guanidine hemisulf ate (GDC 141)

Using the general procedure, l-(4~ fluorobenzyl) guanidine hemisulfate (175mg, 28%) was obtained as a white solid.

MPt 179-181 ⁰C. IR (KBr, cm^"1) 3340 (br) , 3251 (br) , 3160 (br) , 2890 (w) , 1669 (S) , 1157 (s) . δ_H (D₂O) 7.40 (t, 2 x CH, 2H, J=5.4Hz) , 7.25 (t, 2 x CH, 2H, J=5.4Hz) , 4.43 (s, NCH₂, 2H) . δ_c(D₂O:CD₃OD) 161.8 (CHF) , 158.3 (C=NH) , 133.7, 131.1, 117.4, 45.3 (NCH₂) .

CHN Anal. CaIc. for Ci₆H₂₂N₆O₄SF₂ requires C, 44.44; H, 5.09; N, 19.44; S, 7.41. Found C, 44.28; H, 5.14; N, 19.00; S, 7.55.

1- (4-Trifluoromethylbenzyl)guanidine hemisulfate (GDC 146)

Using the general procedure, l-(4- tr±fluoromethyl)benzylguanidine hemisulfate (242mg, 32%) was obtained as a white solid.

MPt 190-194 ⁰C.

IR (KBr, cm^"1) 3503 (w) , 3340 (br) , 3252 (br) , 3152 (br) ,

2891 (w) , 1675 (m) , 1122 (s) . δ_H (D₂O) 7.76 (d, 2 x CH, 2H, J=8.lHz), 7.53 (d, 2 x CH,

2H, J=8.0Hz), 4.67 (s, NCH₂, 2H) . δ_c(D₂O:CD₃OD) 159.8 (C=NH), 143.3, 130.2, 128.4, 46.8

(NCH₂) .

CHN Anal. CaIc. for Ci₈H₂₂N₆O₄SF₆ requires C, 40.60; H, 4.13; N, 15.78; S, 6.01. Found C, 40.69; H, 4.02; N, 15.70; S, 6.20.

1- (naphthalene-2-ylmethyl) guanidine hemisulfate (GDC 132)

Using the general procedure, 1- (naphthalene-2- ylmethyl) guanidine hemisulfate (392mg, 22%) was obtained as a white solid. MPt 160-162 ⁰C. IR (KBr, can^"1) 3326 (br) , 3131 (br) , 3070 (w) , 2900 (w) , 1536 (s) , 1660 (m) .

SH (D₂O) 7.84-7.76 (m, 3 x CH, 3H), 7.45-7.39 (m, 4 x CH, 4H), 4.80 (s, NCH₂, 2H), 3.47 (q, CH₂, 2H, J=7.0Hz), 1.33 (t, CH₃, 3H, J=7.0Hz) . δ_c(D₂O:CD₃OD) 159.2 (C=NH) , 135.9, 133.2, 132.9, 130.7, 128.6, 128.0, 127.4, 126.9, 124.8, 44.9 (NCH₂) . CHN Anal. CaIc. for C₂₄H₂₈N₆O₄S requires C, 58.06; H, 5.64; N, 16.93. Found C, 67.88; H, 6.43; N, 19.39.

1- (4-Bromobenzyl) guanidine hemisulfate (GDC 169)

Using the general procedure, 1- (4- bromobenzyl) guanidine hemisulfate (800 mg, 5.7%) was obtained as a white solid.

MPt 236-237 ⁰C

IR (KBr, can^"1) 3340 (br) , 3251 (br) , 3160 (br) 1660 (S) ,

1152 (S) .

SH (D₂O) 7.62-7.26 (m, 4 x CH, 4H) , 4.42 (s, NCH₂, 2H) . δ_c(CD₃OD) 157.6 (C=NH) , 136.0, 132.1, 124.2, 121.8, 44.5

(NCH₂) .

CHN Anal. CaIc. for C₁₆H₂₂N₆O₄SBr₂ requires C, 34.67; H,

3.97; N, 15.16; Br, 28.85; S, 5.78. Found C, 35.52; H,

3.91; N, 14.70; Br, 29.26; S, 5.19. 1- (2-Bromobenzyl)guanidine hemisulfate (GDC 165)

Using the general procedure, 1- (2- bromobenzyl) guanidine hemisulfate (200mg, 22%) was obtained as a white solid. MPt 255-257 ⁰C.

IR (KBr, can^"1) 3490 (m) , 3343 (br) , 3251 (br) , 3143 (br) , 288 (w) , 1671 (s) , 1107 (s) .

S_H (D₂O) 8.03 (d, CH, IH, J=9.4Hz), 7.69 (m, 2 x CH, 2H), 7.43 (m, CH, IH), 4.80 (s, NCH₂, 2H) . δ_c (D₂O: CD₃OD) 159.8 (C=NH), 137.2, 134.7, 131.3, 130.4, 129.9,124.5 (CHBr), 47.0 (NCH₂) .

CHN Anal. CaIc. for Ci₅H₂₂N₆O₄SBr₂ requires C, 34.65; H, 3.61; N, 15.16; S, 11.55. Found C, 34.60; H, 3.91; N, 14.95; S, 5.95.

Benzylguanidine sulphate (GDC 62)

Using the general procedure, benzylguanidine sulphate (2.4g, 58%) was obtained as a white solid. MPt 208-209 ⁰C.

IR (KBr, cm^"1) 3450 (s) , 3327 (br) , 3151 (br) , 1624 (s) , 1128 (s) .

SH (D₂O) 7.26 (m, 5 x CH, 5H), 4.23 (s, NCH₂, 2H) . δ_c(D₂O:CD₃OD) 158.0 (C=NH), 137.2,130.0, 129.0, 128.0, 45.5

(NCH₂) .

CHN Anal. CaIc. for Ci₅H₂₄N₆O₄S requires C, 48.48; H, 6.06; N, 21.20; S, 8.08. Found C, 48.63; H, 6.12; N, 21.11; S, 8.19. l-(2-Chlorobenzyl)guanidine hemisulphate (GDC 152)

Using the general procedure, 1- {2-chlorobenzyl) guanidine hemisulphate (300 mg, 42%) was obtained as a white solid.

MPt 252-253 ⁰C.

IR (KBr, cm^"1) 3228 (br) , 3141, 1670 (s) , 1624 (m) . δ_H (D₂O) 7.50-7.34 (m, 4 x CH, 4H) , 4.53 (s, NCH₂, 2H) . δ_c(CD₃OD) 157.8 (C=NH) , 134.3, 133.5, 132.9, 131.8, 130.0,

129.8, 127.9, 43.3 (NCH₂) .

CHN Anal. CaIc. for Ci₆H₂₂N₆O₄SCl₂ requires C, 41.56; H,

4.43; N, 17.65; Cl, 15.54; S, 6.75. Found C, 41.29; H,

4.73; N, 18.06; Cl, 15.27; S, 6.88.

Biological studies:

The structural formulae of the compounds used in the biological studies are shown above and in Table 1.

Table 1 :

In vivo study methods:

Adult male BALB/c mice were obtained from stock at the Biological Procedures Unit within the University of Strathclyde. A diet-induced obesity (DIO) mouse model was developed by feeding BALB/c mice on a synthetic high-fat (45 kcal%) diet (Research Diets, Inc., New Brunswick, NJ) post-weaning through to start of experimental procedures. Homozygous obese ob/ob mice were purchased from Harlan UK (Bicester, UK) . All animals were housed individually in an air-conditioned environment maintained at 2 1+2⁰C with a 12h light/12h dark cycle. Animals were allowed continuous access to tap water and unless indicated otherwise were fed ad libitum on standard pellet diet (SDS, Cambridge, UK) . Before the initiation of feeding studies, mice were habituated to being housed individually and had their food intake and bodyweight monitored daily at 09.30.

Feeding studies with galegine and analogs using normal mice:

These studies investigated the effect of the incorporation into the diet of galegine and synthetic galegine derivatives on daily food intake and bodyweight of lean normal mice over a 7-day test period. At the start of the experimental period (Day 0), mice were randomly divided into groups (n=3) and food removed and substituted with standard diet pellets containing 3.41 mmol compound/kg of feed. Daily food intake and bodyweight measurements were recorded for the duration of the 7-day test period and blood glucose and lactate determinations were made at the end of the study. The results are shown in Table 2.

Table 2: Effect of compounds in BALB/c mice Each compound administered in feed for 7 days.

*MA 175 was toxic at the higher dose, the experiment was terminated at day 5. MA 175 is 2-phenyl-2- methylpropylguanidine sulphate and has been described previously in J. Med. Chem. Kh 833 (1967) . ND = not determined.

Feeding studies with galegine and synthetic derivatives using ob/ob mice:

Male 10-week old ob/ob mice (n=6-8) had their feed removed and substituted at Day 0 with standard diet pellets containing 2.27 mmol test compound/kg feed. Daily food intake and bodyweight measurements were recorded for the duration of the study period (see table) . Blood glucose and lactate determinations were made at the end of the study period. The results are shown in Table 3. Table 3: Effect of compounds in ob/ob mice

Feeding studies with galegine and analogs using DIO mice:

These studies investigated the effect of the incorporation into the diet of galegine and synthetic galegine derivatives on daily food intake and bodyweight of mice which had developed an obese phenotype through feeding on a high fat diet for 42 days. At the start of the experimental period (Day 0) , mice were randomly divided into groups (n=β-8) and food removed and substituted with standard diet pellets containing 3.41 mmol test compound/kg feed. Daily food intake and bodyweight measurements were recorded for the duration of the 28-day study period and blood glucose and lactate determinations were made at the end of the study. The results are shown in Table 4. Table 4 : Effect of compounds in DIO mice

Claims

1. A compound according to formula (I), or a physiologically acceptable salt thereof, for weight reduction:

(D wherein, R¹, R², R³ and R⁴ may be the same or different and are independently selected from H or Ci-C₆ alkyl;

R⁵ and R⁶ are independently selected at each position H, Ci-C₆ alkyl or O-alkyl CF₃ or Hal or R⁵ and R⁶ are adjacent and? together form a five or six membered hydrocarbon or heterocylic ring, R⁷ is H or Ci-C₆ alkyl,

2. The compound according to claim 1 wherein where

R⁵ and R⁶ together form a ring, this is phenyl or

3. The compound according to claims 1 or 2 wherein R⁷ is H or methyl.

4. The compound according to claim 1 wherein R⁵ is Hal and n is 0.

5. The compound according to claim 4 wherein R¹, R², R³ and R⁴ are all H.

6. The compound according to claim 5 wherein R⁵ is chlorine or bromine.

7. The compound according to claim 1 wherein R⁵ is H and n is 1.

8. The compound according to claim 7 wherein R¹, R², and R³ are all H, and R⁴ is Ci-C₆ alkyl.

9. A compound according to formula (II), or physiologically acceptable salt thereof:

(ID

wherein,

R⁵ and R⁶ are independently selected at each position H, Ci-C₆ alkyl or O-alkyl CF₃ or Hal or R⁵ and R⁶ are adjacent and together form a five or six membered hydrocarbon or heterocylic ring,

R⁷ is H or Ci-C₆ alkyl,

Hal is selected from F, Cl, Br and I; and n is 0 or 1; and excluding the following compounds and salts thereof : i) R⁵ is H, n is 0, R¹ is H and R² is H, methyl or ethyl, ii) R⁵ is H, n is 1, R¹ and R² are H, R³ and R⁴ are methyl, iii) R⁵ is H, n is 1, R¹, R², R³ and R⁴ are all H, iv) R⁵ is Hal and is Cl, n is 1, R¹, R², R³ and R⁴ are all H, and iv) Hal is F, Cl or Br, n is 0 and R¹ and R² are H.

10. A pharmaceutical composition comprising a compound according to any of claims 1 - 9.

11. Use of a compound according to any of claims 1 - 9 for the preparation of a medicament for weight reduction.

12. The compounds represented by formula (Hi;

(Ill) wherein R⁵ is Hal which is Cl or Br.

13. The compound represented by formula (IV)

wherein, R⁴ is Ci-C₆ alkyl, preferably Ci-C₄ alkyl, most preferably methyl or ethyl, typically methyl.