JPH03376B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to novel pharmacologically active compounds, methods for producing these compounds, and pharmaceutical compositions containing these compounds. A class of compounds known as monoamine oxidase inhibitors (MAO inhibitors) have been used in psychiatry for more than 20 years to treat depression [Gutsman and Gilman, The Pharmacological Basis of Therapeutics, Vol. 6, Macmillan Publishing Company, Inc., New York, 1980, 427.
~See pages 430]. MAO inhibitors currently used in the United States to treat depression are tranylcypromine (PARNATE, SKF), phenelzine (NARDIL, Park-Davis), and isocarboxazide (MARPLAN, Roche). yet another
MAO inhibitor pargyline (EUTRON Abbott)
is available for the treatment of hypertension [Physical Economics Corporation, Oradell, New Jersey, 1980, pp. 1327-1328 (phenelzine), pp. 1466-1468 (isocarboxazid), 1628
-pages 1630 (tranylcypromine), and 521-522
(See page (Pargyrin)). MAO inhibitors can also be used to treat other psychiatric disorders such as phobic anxiety conditions. MAO inhibitors act by increasing the concentration of one or more biologically active monoamines in the central nervous system to alleviate psychiatric conditions such as depression. Monoamine oxidase enzymes (MAOs) play an important role in the metabolic regulation of monoamines as they catalyze the biodegradation of monoamines through oxidative deamination. MAO
By inhibiting monoamines, the decomposition of monoamines is prevented, resulting in increased utilization of monoamines for physiological functions. Among the bioactive monoamines that are known substrates of MAO are (a) catecholamines (e.g. dopamine, epinephrine, and norepinephrine);
and (b) so-called "neurotransmitter" monoamines such as indoleamines (e.g. tryptamine and 5-hydroxytryptamine), (b) so-called "trace" amines (e.g. o
-tyramine, phenethylamine, tele-N-methylhistamine) and (c) tyramine. [Problem to be Solved by the Invention] The usefulness of MAO inhibitors in the treatment of depression is limited by the fact that the administration of these agents can potentiate the pharmacological effects of certain food substrates or drugs, leading to dangerous and sometimes fatal effects. It was a limited opportunity for connection. For example, a person receiving MAO inhibitors may find that MAO inhibitors block the metabolic breakdown of tyramine in the gastrointestinal tract and liver;
Foods with high tyramine content (such as cheese) must be avoided as they result in high circulating tyramine levels, consequent release of catecholamines in the periphery, and ultimately severe hypertension.
The effect of tyramine on blood pressure elevation caused by cheese intake
Synergism with MAO inhibitors and the resulting hypertensive episodes are commonly known as the "cheese reaction" or "cheese effect." Moreover, the customary
Those undergoing MAO therapy may use directly acting sympathomimetics (or precursors thereof) that are themselves substrates for MAO (e.g., dopamine, epinephrine, norepinephrine, or L-dopa) and indirectly used sympathomimetics (or precursors thereof) that are themselves substrates for MAO. drugs (e.g. amphetamine or vasoconstrictors sold in pharmacies,
Cannot be given hay fever or weight-control preparations). Potentiating the pressor effects of indirectly acting sympathomimetics is particularly profound.
This is because such drugs primarily act peripherally by releasing catecholamines at nerve endings, and the concentration of released catecholamines increases with MAO.
This is because the metabolic breakdown of catecholamines, if blocked, would be dangerously elevated.
Additionally, certain MAO inhibitors should not be used in combination with other MAO inhibitors or with antihypertensives, dibenzapine, antidepressants, meperidine, CNS depressants, and anticholinergics. Biochemical and pharmacological studies have shown that the MAO enzyme is “MAO type A” (MAO-A) and “MAO type B”.
It shows that it exists in two forms known as (MAO-B). These forms differ in their distribution in the organs of the body, in their substrate specificity, and in their sensitivity to inhibitors. in general
MAO-A selectively oxidizes the so-called "neurotransmitter" monoamines (epinephrine, norepinephrine, and 5-hydroxytryptamine), while MAO-B
is the “trace” monoamine (o-tryptamine,
phenethylamine, and ter-N-methylhistamine). Both MAO-A and MAO-B oxidize tyramine, tryptamine, and dopamine. However, in humans, dopamine is the preferred MAO-B.
It has been shown to be a substrate for. These forms also differ in their sensitivity to inhibitors and may therefore be preferentially inhibited depending on the chemical structure of the inhibitor and/or the relative concentrations of inhibitor and enzyme. Currently sold in the United States to treat depression
MAO inhibitors (tranylcypromine, phenelzine, and isocarboxazid) are not preferential in their action on MAO. However, various compounds are known in the art as preferential inhibitors of MAO, the most important being clorgyline, pargyline, and L-deprenyl, all of which have been shown to be clinically effective antidepressants. It has been reported. MAO-A is preferentially inhibited by clorgyline, whereas MAO-B is preferentially inhibited by pargyline and L-deprenyl.
The "selectivity" of MAO inhibitors arises from the fact that the inhibitor has greater affinity for one form of the enzyme. Therefore, the selectivity of MAO inhibitors in vivo for MAO-A or MAO-B is dose dependent, and selectivity is lost as the dose increases. Clorgyline, pargyline, and L-deprenyl are selective inhibitors at low doses, but not at high doses. MAO-A and MAO-B
There is a large body of literature on and its selective inhibition [e.g. Gutsman and Gilman, ibid., 204-
205 pages; Neff et al., Life Science 14, 2061
(1974); Murphy, Biochemical Pharmacology, 27, 1889 (1978); Knorr, Chapter 10,
pp. 151-171 and Sandler, Chapter 11, pp. 173-181, in Enzyme Inhibitors as Medicine, edited by M. Sandler, Macmillan Press Limited, London 1980;
Ritzper et al., Psychopharmacology 62, 123.
(1979); Mann et al., Life Science 26, 877
(1980); and monoamine oxidase: structure and alteration.
Various articles in Fundamentals, edited by T. Singer et al., Academic Press, New York.
(see 1979). Among selective inhibitors of MAO, L-deprenyl is of interest because no "cheese effect" is observed at low doses where preferential inhibition of MAO-B occurs.
"See Knorr Teins, pages 111-113, May 1979."
This observation indicates that the intestinal mucosa mainly contains MAO-A;
This is not unexpected as it allows the oxidation and removal of ingested tyramine uninhibited. The selectivity of L-deprenyl over MAO-B suggests its ability to potentiate L-dopa for the treatment of Parkinson's disease without producing peripheral side effects such as hypertension due to the synergism of vasopressor catecholamines. [Lee et al. Lancet, pp. 791-795, October 15, 1977 and Birkmeyer Lancet, pp. 439-443, February 26, 1977]
Day〕. [Means to solve the problem] Consists of compounds. [In the formula, R ₁ is

[Formula], and R ₃ is hydrogen or lower alkoxy. Suitable non-toxic pharmaceutically acceptable salts of compounds of formula are known in the art and include acid addition salts formed by protonation of the alpha-amino group and neutralization of the carboxylic acid group. Contains salts formed. Like any amino acid, the compound can exist in zwitterionic form. Examples of acid addition salts are those formed from the following acids: Hydrochloric acid, hydrobromic acid, sulfonic acid, sulfuric acid, phosphoric acid, nitric acid, maleic acid, fumaric acid, benzoic acid, ascorbic acid, pamoic acid, succinic acid, methanesulfonic acid,
Acetic acid, propionic acid, tartaric acid, citric acid, lactic acid,
Malic acid, mandelic acid, cinnamic acid, palmitic acid, itaconic acid, and benzenesulfonic acid. Examples of salts formed by neutralization of carboxylic acids are metal salts (eg sodium, potassium, lithium, calcium, or magnesium) and ammonium or substituted ammonium salts. Potassium and sodium salts are preferred. A preferred class of compounds are those of formula (i) where R ₁ is 3-hydroxyphenyl. Preferred specific examples of the compounds of the present invention are 2-amino-4-fluoro-3-(3'-hydroxyphenyl)-3-butenoic acid, 2-amino-4-fluoro-3-(3'hydroxy-4' -methylphenyl)-3-butenoic acid. The compounds of the formula are in vivo precursors (or prodrugs) of certain substances that are irreversible inhibitors of MAO and are useful in psychiatry for the treatment of depression. The compound of formula is not an irreversible inhibitor of MAO in vitro. In order to create irreversible inhibition of MAO in vivo and exert their antidepressant effects, compounds of the formula must be converted to the active metabolite, which is 2-phenylallylamine, as shown below by the formula or, respectively. must be done. (R ₁ is

[Formula] and R ₃ is hydrogen or lower alkoxy). Bioconversion of compounds of formula to active metabolites of formula occurs through a decarboxylation reaction catalyzed by an enzyme known as aromatic L-amino acid decarboxylase (AADC).
AADC contains various biologically important amino acids such as dopa, tyrosine, phenylalanine, tryptophan and 5-hydroxytryptophan.
is known to be decarboxylated to produce the corresponding monoamines. Antidepressant compounds that are in vivo and in vitro MAO inhibitors of formula No. 268555, filed on June 1, 1981, are disclosed in Patent Application No. 268555. Bay's pending US application entitled "Allylamine MAO Inhibitor" is described and claimed. AADC is known to exist in both brain and extrabrain tissues. Thus, decarboxylation of compounds of formula can be carried out both in brain and extrabrain tissues, with consequent inhibition of MAO. By administering a compound of the formula in combination with a compound that can preferentially block AADC outside the brain, the decarboxylation reaction that produces the active metabolite occurs primarily in the brain; of
MAO is inhibited. Therefore, administering a compound of the formula in combination with a peripheral AADC inhibitor for the treatment of depression may result in a substantial "cheese effect" and the conventional
This provides the advantage of avoiding other peripheral complications commonly associated with MAO inhibitor therapy. outside the brain
In combination with an AADC inhibitor, compounds of the formula provide site directed inhibition of MAO, with inhibition primarily limited to the brain with high AADC activity. A suitable compound for use in combination with a compound of formula
AADC inhibitors will be apparent to those skilled in the art. Both competitive and irreversible inhibitors may be used. At the dosage used, the AADC inhibitor must be capable of inhibiting AADC outside the brain without substantially inhibiting AADC in the brain. Examples of AADC inhibitors for use in combination with compounds of formula are carbidopa and benzerazide, which inhibit the peripheral decarboxylation of exogenous L-dopa administered for the treatment of parkinsonism. [See Chapter 21, especially pages 482-483, The Pharmacological Basis of Therapeutics, edited by Gudman and Gilman, Macmillan Publishing Company, Inc., New York, 6th edition, 1980]. Other examples of suitable AADC inhibitors are 2-amino-2-(monofluoromethyl or difluoromethyl)-3-(monohydroxyphenyl or dihydroxyphenyl)propionic acid and similar compounds, which were published in 1980. November 26,
Application No. 6/210500, P. Bay and M.
It is described and claimed in a pending US application under the Jungian designation "α-halomethylamino acid." The above 2-halomethylated 2-amino-3-(substituted phenyl)-propionic acid is also covered by Belgian Patent No. 868881.
and 882105. Preferred compounds are 2-amino-2-(monofluoromethyl or difluoromethyl)-3-(3',4'-dihydroxyphenyl)propionic acid and its 2', 3'- or 2',
It is a 5'-dihydroxyphenyl isomer. Methyl 3-phenyl-2 of 2-amino-3-phenyl-3-butenoic acid and 2-amino-3-(3'-hydroxyphenyl)-3-butenoic acid, respectively.
-butenoate and methyl 3-(3'-tetrahydropyraniloxyphenyl)-2-butenoate were described by R. Chari in ``Synthesis of β, γ-unsaturated amino acids as potentially irreversible. Ph.D. thesis entitled ``Enzyme Inhibitors'', published in University of Detroit, 1979 (print available from University Microfilm International, Ann Arboa, Michigan). Compounds of the formula can be prepared by methods known per se as described below. In the above reaction formula, R _c is the formula

[Formula] or

[Formula] or a group defined by R _a in the formula, R _b is (C ₁ -C ₄ ) alkyl, B ₁ is a protecting group for a primary amino group, and X is fluorine, chlorine or bromine, with the proviso that the protecting group (B) defined in R _c or R _a cannot be tetrahydropyranyl. In step A, alkyl 4-halo- of formula XI
The 2-butenoate compound is brominated in a manner known per se, preferably in carbon tetrachloride at 0 DEG C., to give the alkyl 2,3-dibromo-4-halobutenoate compound of formula XII. In step B, the compound of formula XII is dehydrohalogenated to give an alkyl 4-halo- 2-bromo-2
-butenoate compound, which is isomerized in a manner known per se, preferably by treatment with lithium diisopropylamide in THF at -78° C., to the corresponding 3-butenoate compound of formula (step C). In step D, the 3-butenoate compound of formula is treated with ammonia, preferably in dimethyl sulfoxide (DMSO) at ambient temperature to provide an alkyl-4-halo-2-amino-3-butenoate compound of formula, which in step E in a manner known per se to produce the N-protected derivative of formula. The conversion of the N-protected derivative of the formula into the final product of the formula (step F) can be accomplished in a three-step process. This involves (a) removal of the ester alkyl group (R _b ) by alkaline hydrolysis at ambient temperature (preferably with lithium hydroxide in dioxane/water), (b) neutralization of the salt thus formed (approximately PH 4.0, preferably with dilute hydrochloric acid) to give the corresponding free acid; (c) with acid (preferably dilute hydrochloric acid or ethereal hydrogen chloride) under mild conditions (temperatures between 0 and 25°C) for up to 16 hours treatment to remove aromatic OH protecting groups (B) and α-amino groups (B ₁ ). When R _b is the formula tertiary butyl, step (a) and
(b) can be excluded. A further modified procedure can be used if it is desired to prepare compounds of the formula in which the OH group is present in the 3-position of the phenyl ring and the OH or alkoxy is not in the 2- or 4-positions of the phenyl ring. This procedure is similar to that described above for the preparation of compounds of formula, except that the starting materials are
The aromatic OH protecting group (B) defined by R _a is (C ₁ −C ₄ )
Compounds of formula XI which can also be straight chain alkyl groups. This production is carried out in a manner similar to that described in steps A, B, C, D and E above. However, the N-protected derivative produced in step E is
It can be converted in one step to the compound of formula by treatment with 47% hydrobromic acid. Such treatment is aromatic-
Ester alkyl group (R _b ) excluding OH protecting group (B)
, and the α-amino protecting group (B ₁ ) is removed. Alternatively, the N-protected derivative can be treated with dilute hydrochloric acid or saturated ethereal hydrogen chloride to remove the alpha-amino protecting group and then treated with 47% hydrogen bromide. A preferred N-protecting group in step E is tertiary-butoxycarbonyl (Boc), which can be introduced into compounds of formula by methods known per se, such as reaction with di-tert-butyl dicarbonate. Compounds of formula can be prepared in a manner similar to that described for the preparation of compounds of formula using compounds of formula as starting materials. where R _b , R _c and have the meanings defined above for formula XI. The starting material for formula, XI or

【formula】

[Formula] or

It can be prepared in a known manner by the Uittsche reaction by treating the ketone of the formula with a suitable trialkylphosphonoacetate in dimethoxyethane (DME) at 0° C. in the presence of sodium hydride. Ketones of the formula, or, are known compounds or can be prepared from known compounds by methods known in the art or by obvious variations thereof. For example, a compound of formula can be halogenated by known methods to produce a compound of formula X or a suitably substituted benzene compound can be acylated using a Friedel-Crafts reaction. As will be appreciated by those skilled in the art, compounds of the formula have aromatic OH and alpha _NH2 groups, one or both of which can be acylated in a manner known per se. It is known in the art that N-acyl or O-acyl groups derived from alkanoic acids or natural amino acids can be removed to generate free _-NH2 or OH groups in vivo. Acyl derivatives can therefore also be used for the purposes of the present invention, provided that the acyl group is removed in vivo to yield the desired amino acid. It is also recognized that certain other derivatives may be converted in vivo to generate free aromatic hydroxy or alpha-amino groups. Examples of such derivatives are 2-
It is amino-4-fluoro-3-(3',4'-methylenedioxyphenyl)-3-butenoic acid. It is also clear that certain derivatives of carboxylic acid functional groups other than esters and salts can be used for purposes of the present invention. Examples are primary amines, secondary or tertiary alkyl amines and the alpha or terminal end of natural amino acids.
It is an amide formed by the NH ₂ group. This is because amide bonds are known to be cleaved in vivo. Since the compounds of the formula have asymmetric carbon atoms, enantiomers are possible, and the compounds of the invention may be in the form of biologically active enantiomers or racemates. Compounds of formula may be obtained in enantiomeric pure form by resolution of the desired racemic product or by resolution of racemic starting materials or intermediates at any convenient stage of the synthesis. Split implementation methods are well known in chemistry. When a dosage range is given herein, it is also applicable to the racemate. Further, the compound of the formula has the substituent represented by F
The group represented by R ₁ can exist in either cis or trans form. It is understood that the compounds of the invention may exist in pure cis or trans form or as mixtures thereof. When used to treat depression, the effective dosage of a compound of formula will vary depending on the particular compound used, the severity and quality of the depression, and the individual patient being treated. Effective results are generally achieved with compounds of formula at dosage levels of about 0.5 to about 50 mg per day, either orally or parenterally. Treatment should be initiated at a relatively low dosage, with the dosage being increased thereafter until the desired effect is achieved. When an AADC inhibitor is administered with a compound of the formula formula for the treatment of depression, an effective dose of the AADC inhibitor will reduce the AADC of the compound outside the brain without substantially blocking AADC-catalyzed decarboxylation in the brain. It must be possible to substantially block catalytic decarboxylation. Effective dosages will vary, however, depending on the particular compound used and the dose of antidepressant Prodrug administered. Generally, effective results with carbidopa and benizeladide are achieved orally or parenterally at dosage levels of about 50 to 500 mg per day, preferably about 50 to 250 mg per day. The above 2-halomethylated 2-amino-3-(substituted phenyl)
With propionic acid, effective results are approximately
Dosage levels of 0.1 mg to 1000 mg are achieved orally or parenterally. The AADC inhibitor may be administered at substantially the same time as or prior to the administration of the compound of formula. When administered previously, AADC inhibitors may be used prior to treatment depending on the route of administration and the severity of the condition being treated.
It can be given in time. When used in combination with an AADC inhibitor, the compound of formula and the AADC inhibitor are administered separately with each included in a formulation in which the compound or AADC inhibitor is the single active agent. or they can be administered together in a formulation containing both the compound and the AADC inhibitor as active agents. When both drugs are included in a single formulation, the relative amounts of each drug can vary depending on the particular compound used. The compounds of the invention can be administered in a variety of ways to achieve the desired effect. The compounds can be administered alone or in combination with pharmaceutically acceptable carriers or diluents, the proportions and quality of which will depend on the solubility and chemical nature of the chosen compound, the chosen route of administration and standard pharmaceutical practice. It is determined. The compound may be in solid dosage form, such as capsules, tablets, powders or liquid dosage forms;
For example, it can be administered orally in the form of a solution or suspension. The compounds can also be injected parenterally in the form of sterile solutions or suspensions. Solid oral forms may contain conventional excipients such as lactose, sucrose, magnesium stearate,
May include resins and similar materials. Liquid oral forms may contain various flavoring, coloring, preservative, stabilizing, solubilizing, or suspending agents. Parenteral preparations are sterile aqueous or non-aqueous solutions or suspensions that may contain various preservatives, stabilizing agents, buffering agents, solubilizing agents, or suspending agents. If desired, additives such as salt or glucose are added to make the solution isotonic. The amount of active compound administered will vary and can be any effective amount. A unit dosage of these compounds can include, for example, from about 1 mg to 100 mg of the compound;
For example, it may be administered once or more times daily as required. The term unit dosage form is used herein to mean a single or multiple dosage form containing quantities of a certain active ingredient in admixture or otherwise combined with a diluent or carrier. and the above amounts are those in which one or more predetermined units are normally required for a single therapeutic administration. In the case of multiple dose forms such as liquids or scored tablets, the predetermined unit above shall be 5 ml (teaspoon) of liquid in the multiple dose form or half of the scored tablet form. Or it could be a small part like 1/4. In terms of composition, the present invention has the formula [In the formula, R ₁ is

[Pharmacological effect]

2-amino-3-(3'-hydroxyphenyl)-
3-butenoic acid (hereinafter referred to as AHBA), 2-amino-4-fluoro-3-(3'-hydroxyphenyl)
-3-butenoic acid (hereinafter referred to as AFHBA) and 2-
Amino-4-fluoro-3-(3'-hydroxy-
4-methoxyphenyl)-3-butenoic acid (hereinafter
AFMBA) is tested as follows. A. In vitro test AHBA or AFHBA is incubated with partially purified pig kidney AADC at 37° for various times up to 2 hours. HPLC analysis showed that in 2 hours each compound (DL-mixture) underwent 50% decarboxylation and the corresponding allylamine [2-(3'-
hydroxy) phenylallylamine or 2-
(3'-hydroxy)phenyl-3-fluoroallylamine]. 10μM α−
Monofluoromethyl-dopa (MFMD)
When the experiment was repeated in the presence of (AADC inhibitor),
No decarboxylation was observed. Decarboxylation products are MAO in vitro
is a time-dependent irreversible inhibitor of 2-
IC ₅₀ of (3′-hydroxy)phenylallylamine
is up to 10 ^-5 , 2-(3'-hydroxy)phenyl-
The IC ₅₀ of 3-fluoroallylamine is up to 10 ^-9 .
AHBA and AFHBA are inactive or very weak inhibitors of MAO. B. Ex vivo test: AHBA (250 mg/Kg, intraperitoneal) in rats
MFMD administered alone or together with AHBA (250 mg/Kg, intraperitoneal) 30 minutes before AHBA
(1 mg/Kg, intraperitoneal). The rats were sacrificed after 4 hours, and the brain and heart were removed.
Measure MAO activity (tyramine as substrate). Administered alone, AHBA has effects in the brain and heart.
resulted in 30% inhibition of MAO. AHBA in combination with MFMD resulted in 65% inhibition of MAO in the brain. To determine regioselective effects, MAO activity in the rat brain was determined using the neuron substrate 5-HF and the non-neuron substrate phenylethylamine (PEA). AHBA administration in combination with MFMD resulted in neuron MAO (5-
HT substrate) and non-neuronal MAO (PEA substrate) by 15%. MFMD administered to rats alone or with AFHBA (0.5 mg/Kg, ip) 30 minutes before AFHBA
(2.0 mg/Kg, intraperitoneal) in combination. Animals were sacrificed 18 hours later and brain, heart and liver were removed.
MAO activity (5-HT and phenethylamine as substrates) was measured. In the brain, AFHBA administered alone inhibited neuron MAO by 72% and non-neuron MAO by 37%. MFMD preprocessing is
It did not essentially reduce neuronal MAO inhibition (68%) but reduced non-neuronal MAO inhibition by 28%. In the heart, AFHBA is a neuron
While inhibiting MAO by 52% and non-neuronal MAO by 44%, MFMD pretreatment reduced neuronal MAO inhibition to 18% and non-neuronal MAO inhibition to 4%. In the liver, MAO inhibition by AFHBA alone was 29% (neuron) and 38% (non-neuron), whereas MFMD pretreatment completely abolished MAO inhibition. Repeating the above experiment with AFHBA using carbidopa (50 mg/Kg, intraperitoneal),
AADC inhibitors against MAO inhibition in the heart
It provided the same protective effect as MFMD (2.0 mg/Kg, intraperitoneal). To demonstrate AFHBA activity by oral administration, rats were force-fed with various doses of the compound and sacrificed 18 hours later. MAO activity in the brain was measured using 5-HT and phenethylamine (PEA) as substrates. The following results were obtained. MAO inhibition (%) Dose (mg/Kg) Neuron Non-neuron 0.5 63 41 1.0 71 64 2.5 95 83 Rats were injected with AFMBA (100 mg/Kg, intraperitoneally) and sacrificed 18 hours later. 5-HT and
PEA was used to determine MAO activity in the brain, heart and liver. The following results were obtained. MAO inhibition (%) Neuron Non-neuron brain 16 40 Heart 18 46 Liver 2 11 AHBA (334
mg/Kg, ip) alone or in combination with carbidopa (100 mg/Kg, ip) given 30 minutes before administration of AHBA ethyl ester. Animals were sacrificed 4 hours later. 5-HT and
Brain MAO activity was determined using PEA as a substrate. The following results were obtained.

[Table] Vidopa
N ^* Denotes neurotic properties.
C. In Vivo Tests Rats were given MFMD (2 mg/Kg, intraperitoneal) alone or together with AFHBA (0.5 mg/Kg, intraperitoneal) 30 minutes before AFHBA.
mg/Kg, intraperitoneal) or carbidopa (50 mg/Kg,
Intraperitoneal). Rats were sacrificed 18 hours later, and dopamine, DOPAC, and 5-
HT and 5-HIAA concentrations were measured. The following results were obtained.

[Table] In another experiment, rats were given various doses of AFHBA.
was administered orally. Rats were sacrificed 18 hours later, and dopamine, DOPAC, 5-HT, and 5-HT were found in the brain.
HIAA concentration was measured. The following results were obtained.

[Acute toxicity test]

A Mouse 1 Oral and Intraperitoneal The LD ₅₀ of AFHBA was calculated in CD-1 mice. In the first part of the study, mice (5/
200-1600mg/Kg depending on feeding (sex/administration)
A single oral dose of AFHBA was given, but the drug substance was given dissolved in distilled water. 1000 mg/Kg to determine whether the lack of oral toxicity was secondary to poor gastrointestinal absorption, as only a few deaths were observed at these doses.
of AFHBA to 5 additional mice/sex. Thereafter, oral doses of 2000, 3000 and 5000 mg/Kg were given. After administration, all animals were
Observed for weeks. Notable clinical observations include:
These included decreased spontaneous activity at doses above 400 mg/Kg, aggressive behavior at 1200 and 1600 mg/Kg, and perineal soiling at 3000 mg/Kg. . The rate of weight gain appeared to be unaffected by drug doses below 1600 mg/Kg, and even at doses up to 5000 mg/Kg, with animals surviving similar to those of controls. The weight continued to increase at a similar rate. Judging from the above, in CD-1 mice
The acute toxicity of AFHBA is low. At oral doses below 1600 mg/Kg, no more than 2 out of 10 mice died after drug administration. When 1000 mg/Kg was administered intraperitoneally, only 4 out of 10 mice died, suggesting that the low degree of toxicity was not due to poor oral absorption. In rats (see below) the kidneys appear to be the primary site of drug-induced toxicity. Broadly speaking, the kidneys of most spontaneously dying mice have a plump, pale cortex and/or
Or have a dark medulla. Acute renal tubular necrosis was found cytologically in kidney sections above 400 mg/Kg orally or 1000 mg/Kg intraperitoneally. Acute renal failure secondary to acute tubular necrosis is likely to be the major factor in death in mice following single oral or intraperitoneal administration of AFHBA. Those that survived had no gross treatment-related abnormalities upon autopsy 14 days after administration. LD ₅₀ value is 3008 for males
mg/Kg (95% confidence limits of 256-5759 mg/Kg) and 4650 mg/Kg (95% confidence limits of 0-1199 mg/Kg) for females.
confidence limits) (see Table 1 below). B Rat 1 Oral Acute oral toxicity of AFHBA 200, 400, 500, 635
and using a dose of 800 mg/Kg, Sprague-
Evaluations were made in a Dowler rat. The drug substance was dissolved in distilled water and administered by gavage to 5 rats/sex/dose. The rats were then observed for a total of 14 days. Decreased activity, decreased food consumption and excreta output, and porphyrin staining of the nasal passages occurred at all dose levels. Staining of the perineum with dirt was also observed at doses above 500 mg/Kg. 800
Aggression was observed at mg/Kg. The onset of clinical symptoms occurred 1-2 days after administration and lasted for 2-4 days. Death occurred 3-6 days after drug administration. Survivors appeared normal by day 7. Males appeared to be more susceptible to the negative effects of drug administration on weight gain. 400mg/Kg
In , body weight gain decreased in males, while
Weight loss occurred at 500 mg/Kg. In females,
400mg/Kg has no effect on weight gain, while 500mg/Kg
mg/Kg resulted in a decrease in the rate of weight gain (there was no decrease in body weight). Doses of 635 mg/Kg and 800 mg/Kg were fatal in all cases, and the effect on body weight gain could not be evaluated. Autopsy studies revealed that the kidneys were the primary site of toxicity. At doses above 500 mg/Kg, most animals (both spontaneously dying and surviving animals) have signs of nephrotoxicity, including pale cortex and/or dark medulla; progressed to acute tubular necrosis at 800 mg/Kg. Kidney deterioration appeared to be a major factor contributing to death. Lung and liver congestion, urinary cavity distension, mucosal mucosal erosion/stomach ulceration were also observed, primarily at 635 and 800 mg/Kg. The LD ₅₀ for both males and females was calculated to be 525 mg/Kg, with 95% confidence limits of 330-720 mg/Kg (see Table 1 below). 2 Acute intravenous LD ₅₀ measurements for intravenous AFHBA were also made in Spraug-Deureira rats. Five rats/sex/dose were administered AFHBA (dissolved in distilled water). Single doses of 100, 200, 300, and 400 mg/Kg were injected into the tail vein and rats were
Monitored for days. Reduced spontaneous activity by 300
It occurred at doses greater than mg/Kg, started 24 hours after administration, and lasted for 4 days. Food consumption and excrement output also decreased at 300 and 400 mg/Kg. The rate of weight gain was reduced at doses above 200 mg/Kg in both males and females. No deaths occurred in rats given 100 mg/Kg intravenously. In all other groups, rats dying secondary to administration of these drugs died 3-5 days after administration. As with oral administration, cursory pathological studies have revealed that the kidneys are the primary site of toxicity.
In all spontaneously dying animals, the kidney cortex was pale while the medulla was dark colored.
Therefore, as with oral administration, renal deterioration appears to be the major factor contributing to mortality in these animals. In addition, some animals also showed slight distension of the bladder cavity and discoloration of the liver. LD ₅₀ value (and
95% confidence limits), 308 (161-454) for males
mg/Kg, and 241 (142-340) mg/Kg for females.
was calculated (see Table 1).

【table】

[Front] Ragdoure
Female 525(330〓720)
stomach)
Rat(sp intravenous male 308(161〓454)
Ragdoure
Female 241(142〓340)
stomach)
LD ₅₀ values and 95% confidence limits are calculated using Berkson's least chi-square logistic function and are based on deaths occurring within 14 days after dosing. C Monkey 1 Oral Changes in the acute toxicity of AFHBA were obtained in monkeys (5). 2
male cynomolgus monkey (cynomolgus)
monkey) (Macaca fascicularis) was used in this study. Monkeys received rotating single oral doses of increasing amounts of AFHBA ranging from 10 to 160 mg/Kg (administered as a solution or suspension via nasogastric intubation). After each dose of drug, animals were observed for 2-6 days for adverse clinical signs and symptoms. further obtaining a blood sample prior to the first administration of the drug;
After each dose, remove again for 24 hours and platelet MAO
-B activity was measured. Monkeys tolerated AFHBA with minimal adverse effects. One animal developed diarrhea 22 hours after a single dose of 40 mg/Kg. Overt behavior and activity were unaffected by drug administration. Platelet MAO-B activity appeared to be inhibited at all doses tested.

Claims (1)

[Claims] 1 formula [In the formula, R ₃ is hydrogen or lower alkoxy. ]
or a non-toxic pharmaceutically acceptable salt thereof. 2 formulas [In the formula, R ₃ is hydrogen or lower alkoxy. ]
or a non-toxic pharmaceutically acceptable salt thereof;
in admixture or otherwise together with a pharmaceutically acceptable carrier or diluent;
Composition for treating depression.