Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D263/00—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings
  • C07D263/02—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings
  • C07D263/08—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
  • C07D263/16—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D263/18—Oxygen atoms
  • C07D263/20—Oxygen atoms attached in position 2
  • C07D263/22—Oxygen atoms attached in position 2 with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to other ring carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C229/00—Compounds containing amino and carboxyl groups bound to the same carbon skeleton
  • C07C229/02—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton
  • C07C229/34—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton containing six-membered aromatic rings

Definitions

• the present invention relates to 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid and bioprecursors thereof.
• This invention further relates to processes and intermediates for their preparation, to their use in methods of therapy and to pharmaceutical compositions containing them.
• the compounds of the present invention are ⁇ 3 -adrenoceptor agonists and are of value in disease conditions mediated through such adrenoceptors.
• Administration of the compounds of this invention to warm-blooded animals provides a thermogenic effect, that is thermogenesis is stimulated and administration of the compounds is of use, for example, in the treatment of obesity and related conditions such as mature onset diabetes associated with obesity.
• the compounds of this invention improve glucose tolerance in warm-blooded animals and are of use in combatting disease conditions wherein such activity is beneficial for example they have hypoglycaemic activity.
• the compounds of this invention may also be used in the treatment of non-insulin dependent diabetes mellitus (NIDDM) and in conditions wherein insulin resistance is of importance such as hypertension, hyperlipidaemia and decreased fibrinolysis (Reaven's syndrome or Syndrome X).
• NIDDM non-insulin dependent diabetes mellitus
• Reaven's syndrome or Syndrome X Reaven's syndrome or Syndrome X
• R a is hydrogen or fluoro
• R b and R c are independently selected from hydrogen and C 1-3 alkyl
• Z is hydroxymethyl or a group of the formula -COR d in which R is hydroxy, C 1 ,alkoxy or amino.
• R a is hydrogen or fluoro and R e and R f are independently hydrogen or a variety of groups leading to secondary and tertiary amides. It is believed that compounds of the formula (A) wherein R is alkoxy or amino, and the compounds of the formula (B), are primarily bioprecursors that are effective via the corresponding oxyacetic acid; that is the compound of the formula (A) wherein R is hydroxy.
• thermogenic effect for example lack of cardiac side-effects
• selectivity of thermogenic effect is an important requirement for a useful therapeutic agent in the treatment of, for example, obesity and related conditions.
• This compound of the present invention is a carboxylic acid and shows significant advantage over the above referred to secondary amide and free carboxylic acid. In particular, it has been shown to have full efficacy at ⁇ 3 -adrenoceptors, whereas the compound which had been administered to man was found to have low efficacy. In addition, it has been shown to have surprisingly good solubility and absorption characteristics.
• R 1 is hydrogen or methyl
• R 2 is hydrogen or methyl
• R 3 is hydrogen, fluorine, chlorine, bromine, trifluoromethyl or C 1-6 alkyl
• n is 1 or 2
• X is C 1-6 straight or branched alkylene
• R is C 1-6 alkoxy, hydroxy, or amino optionally substituted with one or more lower alkyl groups
• A is hydrogen, fluorine, chlorine or bromine.
• thermogenic behaviour at doses which cause relatively few side-effects as referred to hereinabove. It has a particularly good profile of activity as evidenced for example by potency in the GDP binding test, lipolytic activity, selectivity for ⁇ -adrenoceptors and effects on plasma glucose, insulin and fatty acid levels.
• 4-[2-(2-Hydroxy-2-phenylethylamino)ethyl]phenylacetic acid is amphoteric and may be used in the zwitterionic form, or as a pharmaceutically acceptable acid addition salt, or as a salt with a base affording a pharmaceutically acceptable cation.
• pharmaceutically acceptable acid-addition salts include, for example, salts with inorganic acids such as hydrohalides
• salts with bases affording a pharmaceutically acceptable cation include, for example, alkali metal and alkaline earth metal salts, such as sodium, potassium, calcium and magnesium salts, and ammonium salts and salts with suitable organic bases such as triethanolamine.
• Bioprecursors of the compound of the formula (I) are those pharmaceutically acceptable compounds that are degraded in the animal body to produce the parent acid. Such compounds can be identified by administering, for example orally to a test animal, the compound under test and subsequently examining the test animal's body fluids.
• bioprecursors include the ester, amide, secondary amide and tertiary amide derivatives of the carboxylic acid function.
• bioprecursors may be formed at the -CH(OH)- hydroxy function for example -CH(OCOR)- compounds wherein R is C, fi alkyl in particular methyl.
• Particularly suitable bioprecursors are the
• Bioprecursors of 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid may have a thermogenic effect in their own right and this is another aspect of the present invention.
• 4-[2-(2-hydroxy-2-phenylethylamino)ethyl] phenylacetic acid and bioprecursors thereof contain an asymmetric carbon atom and can exist as optically active enantiomers or as an optically inactive racemate.
• the present invention encompasses any enantiomer or racemate which when administered in a therapeutic amount provides a thermogenic effect in warm-blooded animals, it being well known in the chemical art how to prepare individual enantiomers, for example by resolution of the racemate or by stereospecific synthesis, and how to determine the thermogenic properties, for example, using the standard tests described hereinafter. It is preferred that the compounds of the present invention are provided in the (R) absolute configuration at the -CH(OH)- group (under the
• a compound of the present invention or a pharmaceutically acceptable salt thereof for the therapeutic treatment of warm-blooded mammals including humans, in particular for treating obesity, it is normally formulated in accordance with standard pharmaceutical practice as a pharmaceutical composition.
• the present invention provides a pharmaceutical composition which comprises 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid, or a bioprecursor thereof or a pharmaceutically acceptable, salt thereof and a pharmaceutically acceptable carrier.
• compositions of this invention may be administered in standard manner for example by oral or parenteral administration.
• they may be formulated by means known to the art into the form of, for example, tablets, capsules, pills, powders, aqueous or oily solutions or suspensions, emulsions, and sterile injectable aqueous or oily solutions or suspensions.
• compositions for oral administration are preferred.
• compositions may be obtained using standard excipients and procedures well known in the art.
• a unit dose form such as a tablet or capsule will usually contain, for example 0.1-500 mg of active ingredient, more suitably 10-250mg, and preferably 50-100mg of the compound of this invention.
• compositions may also contain other active ingredients known for use in the disease conditions to be treated, for example appetite suppressants, vitamins, antihypertensives and hypoglycaemic agents such as sulphonylureas, biguanides and thiazolidinediones. It is understood that such compositions cover co-formulation, concurrent and sequential therapy of the two or more active ingredients.
• active ingredients known for use in the disease conditions to be treated, for example appetite suppressants, vitamins, antihypertensives and hypoglycaemic agents such as sulphonylureas, biguanides and thiazolidinediones. It is understood that such compositions cover co-formulation, concurrent and sequential therapy of the two or more active ingredients.
• 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid or a bioprecursor thereof may be formulated for oral administration in a sustained (or delayed) release composition, for example a matrix tablet formulation comprising insoluble or swellable polymeric filler, or a coated spheroid
• the compounds of the present invention lower triglyceride levels and cholesterol levels and raise high density lipoprotein (HDL) levels and are therefore of use in combatting medical conditions wherein such lowering (and raising) is thought to be beneficial.
• HDL high density lipoprotein
• hypertriglyceridaemia hypercholesterolaemia and conditions of low HDL levels in addition to the treatment of atherosclerotic disease such as of coronary, cerebrovascular and peripheral arteries, cardiovascular disease and related conditions.
• the present invention provides a method of lowering triglyceride and/or cholesterol levels and/or increasing HDL levels which comprises administering, to an animal in need thereof, a therapeutically effective amount of 4-[2-(2-hydroxy-2-phenylethylamino)ethyl] phenylacetic acid or a bioprecursor thereof or pharmaceutically acceptable salt thereof.
• the present invention provides a method of treating atherosclerosis which comprises administering, to an animal in need thereof, a
• compositions are formulated and administered in the same general manner as detailed above for producing a thermogenic effect. They may also contain other active ingredients known for use in the treatment of atherosclerosis and related conditions, for example fibrates such as clofibrate, bezafibrate and gemfibrozil; inhibitors of cholesterol biosynthesis such as HMG-CoA reductase inhibitors for example lovastatin,
• simvastatin and pravastatin inhibitors of cholesterol absorption for example beta-sitosterol and (acyl CoA: cholesterol acyltransferase) inhibitors for example melinamide; anion exchange resins for example cholestyramine, colestipol or a dialkylaminoalkyl derivative of a cross-linked dextran; nicotinyl alcohol, nicotinic acid or a salt thereof; vitamin E; and thyromimetics.
• the compounds of the present invention stimulate the "atypical" ⁇ -adrenoceptors in the gastrointestinal tract and therefore inhibit gastrointestinal motility. They may be of use in combatting medical conditions wherein stimulation of "atypical" ⁇ -adrenoceptors in the gastrointestinal tract is thought to be beneficial, such as in combatting medical conditions wherein inhibition of gastrointestinal motility is thought to be of value. Thus they may be of use for example in the treatment of inflammatory bowel disease (IBD) (such as Crohn's disease and ulcerative colitis), irritable bowel syndrome (IBS), non-specific diarrhoea and dumping syndrome.
• IBD inflammatory bowel disease
• IBS irritable bowel syndrome
• the present invention provides a method of stimulating the "atypical" ⁇ -adrenoceptors in the gastrointestinal tract which comprises administering, to an animal in need thereof, a therapeutically effective amount of a compound of the present
• the present invention provides methods of inhibiting gastrointestinal motility, treating IBD, treating IBS, treating non-specific diarrhoea and treating gastric emptying in dumping syndrome which comprise administering to an animal in need thereof, a therapeutically effective amount of a compound of the present invention.
• the present invention provides a process for preparing 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid or a bioprecursor thereof or a pharmaceutically acceptable salt thereof which process comprises: a) reacting a compound (II) or (III) with a compound of the formula (IV) :
• R is protected carboxy group as hereinabove defined; f) converting 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid into a bioprecursor, or vice versa, or converting a bioprecursor of 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid into another bioprecursor of 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid; g) reducing a compound of the formula (X):
• R 5 is as hereinbefore defined; i) reducing a compound of the formula (XII): wherein R 5 is as hereinbefore defined; and wherein any functional group is optionally protected and thereafter if necessary;
• Protecting groups may in general be chosen from any of the groups described in the literature or known to the skilled chemist as appropriate for the protection of the group in question, and may be introduced by conventional methods.
• Protecting groups may be removed by any convenient method as described in the literature or known to the skilled chemist as appropriate for the removal of the protecting group in question, such methods being chosen so as to effect removal of the protecting group with minimum disturbance of groups elsewhere in the molecule.
• a particular protecting group is a hydrogenolysable group present on the nitrogen atom of -CH(OH)CH 2 NCH 2 CH 2 -.
• the protecting group is benzyl or a substituted benzyl group.
• Such a protecting group may be removed in conventional manner using methods of catalytic hydrogenation, for example palladium on carbon catalysts in an atmosphere of hydrogen. Suitable conditions include ambient and elevated temperatures and pressures in a solvent such as a C 2-6 alkanol for example ethanol or propan-2-ol.
• Compounds corresponding to formula (I) protected with a hydrogenolysable group on the nitrogen atom may be prepared by methods analogous to those described above for formula (I).
• the protected carboxy group R 5 may represent the desired bioprecursor group in which case there is no need to perform a deprotection reaction.
• an acid addition salt of an amine for example of structures (IV) or (VII)
• the reaction may be carried out advantageously in the presence of an acid binding agent such as an inorganic salt, for example, sodium carbonate or potassium carbonate, or a metal alcoholate, for example, sodium methoxide, sodium ethoxide or potassium tert-butoxide, or a suitable organic amine, preferably a tertiary amine, for example, triethylamine.
• an acid binding agent such as an inorganic salt, for example, sodium carbonate or potassium carbonate, or a metal alcoholate, for example, sodium methoxide, sodium ethoxide or potassium tert-butoxide, or a suitable organic amine, preferably a tertiary amine, for example, triethylamine.
• reaction between a compound of the formulae (II) or (III) and a compound of the formula (IV) may be performed in a suitable solvent for example an alcohol such as methanol, ethanol or
• L may be, for example, halogen such as chloro or bromo or an arylsulphonyloxy group such as toluenesulphonyloxy or an alkanesulphonyloxy group such as
• the compound of the formula (V) may be hydrolysed to 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid or a bioprecursor thereof under conditions known in the beta adrenergic blocker art; for example via alkaline hydrolysis in a suitable solvent for example an alkanol at an elevated temperature.
• the compounds of the formula (V) may be prepared by the reaction of a compound of the formula (VIII) with a compound of the formula (XIII):
• the compounds of the formula (V) may be prepared by the reaction of a compound (II) with a compound of the formula (XIV):
• R 5 is as hereinbefore defined and R 7 O- is a leaving group, for example R 7 O- is C 1-4 alkoxy.
• examples of hydrolysable groups R include C 1-6 alkoxy and -NR a R b groups so that -COR
• Such groups represents a C 1-6 alkyl ester or an amide function.
• Such groups may be hydrolysed (acidic, basic, enzymatic) to a group -CO 2 H under
• hydrolysable moiety also represent examples of interconversions of a bioprecursor of 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acetic acid into 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid.
• Suitable acid conditions are for example a strong mineral acid such as hydrochloric, sulphuric or phosphoric acid, conveniently at a temperature in the range, for example, 20° to I10°C and in a polar solvent, such as water, a C 1-4 alkanol (for example methanol or ethanol) or acetic acid.
• the corresponding mineral acid salt of 4-[2-(2-hydroxy-2-phenylethylamino)ethyl] phenylacetic acid may be conveniently isolated.
• base conditions may be used, for example lithium, sodium or potassium hydroxide, conveniently in a suitable solvent or diluent such as an aqueous C 1-4 alkanol at a temperature in the range, for example, 10° to 110°C; or an alkali halide for example lithium chloride in a polar solvent such as dimethylsulphoxide.
• the decomposition may be carried out, for example, by thermolysis at a temperature in the range, for example, 100 to 220°C, alone or in the presence of a suitable diluent such as diphenyl ether.
• the compounds of the formula (VI) may be prepared by methods analogous to those described hereinabove for 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid or a bioprecursor thereof, with optional protection of the amino function for example with a benzyl group.
• 4-[2-(2-Hydroxy-2-phenylethylamino)ethyl]phenylacetic acid and amide bioprecursors thereof may be converted to ester precursors thereof.
• Suitable conditions are, for example, under reflux in the corresponding alkanol under acidic conditions, for example, with the addition of concentrated sulphuric acid as a catalyst.
• the reduction of the compounds (X), (XI) and (XII) may be carried out by conventional chemical or catalytic methods, such as chemical reduction using sodium borohydride or by catalytic
• catalysts such as palladium on charcoal, or platinum.
• Reduction by sodium borohydride is conveniently carried out in alcohol such as methanol and the reaction is generally carried out at from 0 - 20°C.
• Catalytic reduction is conveniently carried out in a conventional hydrogenation solvent such as an alcohol, for example ethanol.
• the hydrogenation is generally carried out under hydrogen gas at about 1 to about 10 atmospheres pressure and at ambient or elevated temperature.
• reaction between a compound of the formula (XV) and a compound of the formula (IV) may be performed in a suitable solvent such as an alcohol or an ether, for example methanol or diethyl ether, at a temperature in the range, for example, -10 to 110°C and most conveniently at ambient temperature.
• a suitable solvent such as an alcohol or an ether, for example methanol or diethyl ether, at a temperature in the range, for example, -10 to 110°C and most conveniently at ambient temperature.
• L ' ' may be, for example, halogen such as chloro or bromo.
• the resulting compounds of the formula (X) may be converted into 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid or bioprecursors thereof in situ.
• the compounds of the formula (XV) may be prepared by methods known in the art.
• the reaction between a compound (XVI) with a compound of the formula (IV) may be performed in a suitable solvent such as an alcohol, for example, ethanol at a temperature range, for example, 0-80°C and most conveniently at ambient temperature.
• a suitable solvent such as an alcohol, for example, ethanol at a temperature range, for example, 0-80°C and most conveniently at ambient temperature.
• the resulting compounds of the formula (XI) may be converted into 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid or bioprecursors thereof in situ.
• reaction between a compound of the formula (XVII) and a compound (VII) may be performed in a suitable solvent such as an alcohol, for example, ethanol, at a temperature in the range, for example, 0 - 80°C and most conveniently at ambient temperature.
• a suitable solvent such as an alcohol, for example, ethanol
• the resulting compounds of the formula (XII) may be converted into
• R 5 is as hereinbefore defined and R 8 and R 9 are independently hydrogen or C 1-4 alkyl.
• Suitable conditions for hydrolysis are, for example, a strong mineral acid such as hydrochloric or sulphuric; conveniently at a temperature range, for example, 20 - 110°C, in a suitable solvent such as tetrahydrofuran, dichloromethane or diethyl ether.
• Bioprecursor esters of the hydroxy group may be prepared in conventional manner for example by reacting the hydroxy group with an activated derivative of an acid under conditions known in the beta adrenergic blocker art.
• salts may be prepared by reacting 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid or a bioprecursor thereof with the appropriate acid or base in conventional manner.
• a hydrogen halide salt it may conveniently be obtained by hydrogenation of the free base together with a stoichiometric amount of the corresponding benzyl halide.
• thermogenic effects of 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetic acid and bioprecursors thereof may be demonstrated using one or more of the following standard tests:
• thermogenic effects of compounds of the formula (I) and bioprecursors thereof may be demonstrated using one or more of the following standard tests:-
• Rats are cold adapted at 4°C for 5 days to increase their capacity for thermogenesis. They are then transferred to a warm environment of 25°C for 2 days. On the following day, a test compound is administered sub-cutaneously or orally. Animals are sacrificed one hour later and the interscapular, brown adipose tissue (BAT) pad is removed. BAT mitochondria are prepared by differential centrifugation and GDP binding is determined (Holloway et al., British J. Pharmacol. (1991), 104 97-104) as a measure of thermogenic activation.
• Each test includes a control which is dosed with the solution/suspension vehicle only and a positive control which is dosed with isoprenaline (as its sulphate) at 1mgkg -1 .
• Test compounds are routinely dosed at 0.1, 0.3, 1.0, 3.0, and 10 mgkg and results expressed in terms of the effect on GDP binding produced by the positive control. From these results, a dose (ED 50 ) necessary to produce 50% of the isoprenaline effect is calculated by curve fitting.
• Rats are adapted to a thermoneutral environment (29°C) for 2 weeks in order to decrease their capacity for BAT mediated non-shivering thermogenesis. During the final 5 days the animals are trained to use an apparatus for measuring heart rate non-invasively via foot-pad electrodes connected to an ECG integrator giving a continuous read-out of heart rate. A test compound is administered
• heart rate is determined 15-30 minutes after dosing.
• the procedure is then repeated in subsequent tests using increasing multiples of the ED 50 determined in test (a) until the heart rate (HR) reaches or exceeds 500 beats per minute, or until the dose reaches 100 times the ED 50 determined in test (a).
• the dose necessary to produce a heart rate of 500 beats per minute (D 500 dose) is estimated.
• the ratio of D 500 to ED 50 in test (a) can be defined as the selectivity index (SI) and provides a measure of the selectivity of the compound for BAT as opposed to the cardiovascular system. Compounds are considered to have significant selectivity which have an
• Rats are kept at 23°C for at least two days, then fasted overnight. On the following day, the basal metabolic rate of the animals is determined using a close-circuit oxygen consumption apparatus of the type described by Alakel et al., 1984, J. Appl.
• test compound Physiol. Respirat. Environ. Exercise Physiol., 1984, 57 (5) 1591-1593.
• the rats are then dosed (orally) with test compound at about 1 mgkg -1 as a solution or suspension in 0.025% w/v Polysorbate 80 (0.5ml/100g) .
• Metabolic rate is then determined for at least one hour after dosing. Compounds are considered active in this test if they cause a
• the potential slimming effects of the compound of Example 5 have been assessed in obese (fa/fa) Zucker rats.
• Obese Zucker rats continue to store fat and increase body weight for most of their life span, and most develop complications or die before a stable body weight is achieved. Therefore the effects of the compound of Example 5 on obese Zucker rats were assessed in animals which were still gaining weight at a low rate.
• Obese (fa/fa) male, Zucker rats were caged singly and allowed free access to powdered rat diet and water for a period of one week. Over this period the average intake of food was determined and medicated diets were prepared so as to provide intakes of the compound of Example 5 equivalent to 2.0 and 20 mg/kg/24 hours. Rats were allocated to treatments with control or the compound of Example 5 medicated diet so that the mean body weight of each group was similar at the start of the experiment. Intake of food was measured on alternate days, and body weight determined weekly. After eight weeks of treatment the rats were killed and the interscapular fat pad excised for analysis of mitochondrial protein and GDP binding.
• Mitochondria were prepared by differential centrifugation (Holloway et al., British J. Pharmacol. (1991), 104, 97-104), Mitochondrial protein was determined by the method of Lowry et al., ((1951) J. Biol. Chem. 193, 265-275) and suspensions adjusted to 2 mg/ml. Specific GDP binding was determined from the total GDP binding determined as described in Holloway et al (British J. Pharmacol (1991), 104, 97-104), after subtraction of the nonspecific GDP binding determined by the same method but in the presence of excess (200 ⁇ M) unlabelled GDP.
• thermogenesis was significantly increased at both doses tested.
• Example 5 did not lead to a reduction in plasma triglycerides. This is likely to be because the doses of compounds administered were insufficient to significantly affect this parameter. 24 hour fasted rat test
• mice Male rats (125 - 150)g were allowed a one week acclimatisation period prior to a 24 hour fast. After fasting, compound of example 5. (0.5, 5.0 or 50 mg/Kg p.o.) dissolved in an aqueous solution of 0.025% polysorbate, was administered by gavage at 0.5 ml/100g body weight. Control rats were dosed with polysorbate solution alone. 60 minutes later, rats were anaesthetised and a cardiac blood sample taken.
• Plasma glucose, insulin and free fatty acid levels were determined using standard methods.
• the compound of Example 5 provides a significant reduction in plasma glucose concentration and a dose dependent increase in plasma insulin and NEFA concentration, one hour after dosing. The experiments were repeated on groups of rats that had been fasted for only 5 hours prior to dosing. Significant increases in plasma insulin and NEFA levels and reductions in plasma glucose were observed.
• mice Male rats (125 - 150 g) were allowed an acclimatisation period of one week, prior to an overnight fast (18 hours). After fasting, a group of six rats was anaesthetised and a cardiac blood sample taken. Other rats were then dosed with the compound of example 5. (5.0 mg/Kg p.o.) dissolved in an aqueous solution of 0.025% polysorbate, control rats were dosed with polysorbate solution alone, at 0.5 ml/100g body weight. 60 minutes later, six rats from each of the two groups (control and example 5. at 5.0 mg/Kg) were anaesthetised and a cardiac blood sample taken.
• the remaining rats were dosed with D-glucose at lg/kg by gavage at 0.5 ml/100g body weight.
• Six rats from each of the two groups were then anaesthetised at 20 minutes, 60 minutes and 120 minutes after the administration of glucose, and a cardiac blood sample taken. Plasma glucose and insulin levels were determined using standard methods.
• example 5- at 5mg/Kg p.o. produced a significant improvement in oral glucose tolerance in the rat. This was associated with a large increase in plasma insulin concentration, one hour after administration of example 5, (prior to glucose).
• the response to an lg/kg oral glucose challenge was measured in rats which had been treated with example 5. at 5.0 mg/Kg, dissolved in 0.025% polysorbate, twice daily for 14 days. Control rats were dosed with polysorbate solution alone, for 14 days. On day 14 rats were fasted overnight, prior to an oral glucose tolerance test.
• mice After fasting, six rats from each treatment group, (control and example 5) were anaesthetised and a cardiac blood sample taken. The remaining rats were dosed either with example 5 or control vehicle as appropriate. 60 minutes later, six rats from each group (control or example 5), were anaesthetised and a cardiac blood sample taken. The remaining rats were dosed with D-glucose at lg/kg by gavage at
• mice 0.5ml/100g body weight.
• Six rats from each group (control or example 5) were anaesthetised at 20 minutes, 60 minutes, and 120 minutes after the glucose administration and a cardiac blood sample taken. Plasma glucose and insulin levels were measured using standard methods.
• Example 5 reduced the glycaemic response to a lg/kg oral glucose challenge.
• the improvement in glucose tolerance after 14 days administration of Example 5 was not associated with any significant increases in plasma insulin concentration, when compared to the control rats.
• C57BL/KsJ (db/db) female mice were divided into two groups and allowed free access to control diet or diet containing the compound of Example 5 as a dietary admix at a dose of 1, 10 and 100 mg/kg body weight/day.
• a group of control (+/+) mice was also included in the experiment.
• blood samples were taken from the hearts of the mice for determination of blood glucose levels.
• Blood and plasma glucose were estimated using the glucose oxidase peroxidase system.
• NEFA were estimated using a WAKO NEFA C kit and plasma insulin by radio immunoassay.
• Epididymal adipose tissue was excised from male rats and adipocytes prepared by digestion with collagenase. Cells were isolated by flotation and washed four times with Krebs Ringer
• KRB Bicarbonate buffer
• KRB/BSA bovine serum albumin
• Lipolytic activity of the compounds was assessed by determining the increase in free fatty acid concentrations caused by the compounds compared to controls.
• the maximal effects (efficacy) of the compounds were determined and expressed as percentage of the maximal effect of isoprenaline.
• Hearts were rapidly removed from guinea-pigs and placed into oxygenated Krebs solution.
• the right atrium was located and dissected from the the rest of the heart and mounted on a pair of platinum electrodes. Once fixed to the electrodes, the tissue was immersed into a 20 ml bath containing oxygenated Krebs solution to which had been added ICI 118551 (0.1 ⁇ M, to block ⁇ 2-adrenoceptors).
• the electrodes were then connected to a modular cardiotachometer which counted the number of spontaneous beats in 10 sec. epochs.
• a computer (IBM PS 2000 or equivalent) averaged the epochs in groups of 3 and displayed these on the computer screen at 1 minutes intervals.
• concentration responses to isoprenaline were performed. Following washout, the test compound was added to the bath and left in contact with the tissues for 60 min., during which time any change in rate was measured. After this time, the concentration responses to isoprenaline were repeated.
• Agonist activity of the test compound was compared to the maximal increase in rate produced by isoprenaline and expressed as a
• Antagonist activity of the test compound was determined by comparing the EC50 values of isoprenaline before and after exposure to the ICI compounds, thus:
• Antagonist activity (concentration ratio) 2.74 ⁇ 0.53 Guinea-pig trachea ( ⁇ 2 -adrenoceptors)
• Antagonist activity of the test compound was expressed as a percentage of the maximal relaxation produced by isoprenaline.
• Antagonist activity was expressed as for the atrium.
• Antagonist activity (concentration ratio) 1.07 ⁇ 0.21%
• Guinea-pigs were of either sex, weighing between 300-500 g.
• ICI 118551 and CGP 20712A are referred to inter alia by
• the precipitated solid was crystallised from a solution of methanol and methyl acetate to give methyl 4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenylacetate as the hydrochloride, m.p. 159-160°C.
• Methyl 4-(2-aminoethyl)phenylacetate hydrochloride may be made in the same way as the corresponding ethyl ester described in UK Patent Specification 1511095.
• the hydrochloride salt of the methyl ester was crystallised from a mixture of methanol and methyl acetate and had m.p. 200-202°C; microanalysis: found C, 57.6; H, 7.1; N, 6.0; Cl, 15.4%; required for C 11 H 15 NO 2 ; C, 57.5; H, 7.0; N, 6.1; Cl, 15.4%.
• Phosphorus tribromide (1.35 ml) was added over 5 minutes to a solution of 2.7 g of this liquid in dichloromethane (75 ml) maintained ⁇ 30°C and under an atmosphere of argon. The mixture was stirred for 4 hours before ice (25 g) was added and stirred continued for a further 30 minutes. The organic layer was separated, washed with saturated aqueous sodium bicarbonate (10 ml) and water (2 ml) and evaporated to a yellow oil/solid mixture. The mixture was subjected to chromatography on Kieselgel 60, Art 9385 (180 g) eluting with hexane/ethyl acetate (6:4).
• administration to warm-blooded animals comprises as active ingredient a compound of formula (I), or a pharmaceutically acceptable salt thereof, as defined hereinbefore (for example as described in one of the preceding Example), and may be produced by aqueous granulation or direct compression together with milled lactose containing a standard disintegrant and/or lubricant.
• the direct compression method may be used wherein the active ingredient is mixed with lactose in the ration of 1:10 parts by weight and/or
• microcrystalline cellose containing 0.5% by weight of a lubricant (such as magnesium stearate) and 5% by weight of a disintegrant (such as cross-linked sodium carboxymethyl cellulose or sodium starch glycolate).
• a lubricant such as magnesium stearate
• a disintegrant such as cross-linked sodium carboxymethyl cellulose or sodium starch glycolate.
• An example a tablet prepared by aqueous granulation is that containing active ingredient (50-100 mg), lactose (230 mg), maize starch (80 mg), gelatine (2.2 mg), magnesium stearate (4 mg) and croscarmellose sodium (7 mg).

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=10714625

Family Applications (1)

Country Status (8)

Families Citing this family (13)

Family Cites Families (2)

• 1992
  • 1992-04-27 GB GB929209076A patent/GB9209076D0/en active Pending
• 1993
  • 1993-04-07 GB GB939307238A patent/GB9307238D0/en active Pending
  • 1993-04-16 IL IL105427A patent/IL105427A0/xx unknown
  • 1993-04-19 ZA ZA932734A patent/ZA932734B/xx unknown
  • 1993-04-20 WO PCT/GB1993/000821 patent/WO1993022277A1/en not_active Application Discontinuation
  • 1993-04-20 AU AU39612/93A patent/AU3961293A/en not_active Abandoned
  • 1993-04-20 CA CA002111967A patent/CA2111967A1/en not_active Abandoned
  • 1993-04-20 EP EP93909068A patent/EP0591503A1/de not_active Withdrawn
  • 1993-04-20 JP JP5519032A patent/JPH08501770A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events