GB809913A - A new acid derived from an alkaloid named "deserpidine," its esters and salts thereof, and process for their manufacture - Google Patents

Abstract

The invention comprises deserpidic acid, deserpidic esters, O-acylated deserpidic esters (except deserpidine itself (see Specification 809,912)) and salts of these. Deserpidic acid is obtained by alkaline hydrolysis of deserpidine, mild conditions or the presence of a trans-esterifying alcohol leading to alkyl deserpates. The free hydroxyl group may subsequently be esterified with aliphatic, aromatic, araliphatic or heterocyclic carboxylic acids, or with sulphonic acids, preferably in the form of their functional derivatives such as halides or anhydrides. Deserpidic acid may be esterified at the carboxyl group by treatment with a diazoalkane or an alcohol in the presence of a strong acid. In the examples: (1) deserpidine is hydrolysed to methyl deserpidate and to deserpidic acid, the last two being interconverted; (2) deserpidic acid is converted into its methyl, ethyl and butyl esters; (3) methyl deserpidate is esterified with acetic, 3:4 - dimethoxybenzoic, 3:4:5 - trimethoxybenzoic (giving deserpidine), piperonylic, 3:4:5-trimethoxycinnamic, 2-naphthoic, 2-furoic, nicotinic, quinoline-6-carboxylic and toluene-p-sulphonic acids; (4) ethyl deserpidate is esterified with 3:4:5-trimethoxybenzoic acid; and (5) butyl deserpidate is esterified with acetic acid. Other esterifying acids mentioned are benzoic, p-methoxybenzoic, 3:4:5-triethoxybenzoic, O-carbalkoxy-syringaic, phenylacetic, mandelic, tropic, cinnamic, p-methoxycinnamic, thienoic and picolinic. Salts may be formed with inorganic or organic acids, e.g. hydrochloric, nitric, sulphuric, phosphoric, isothionic, acetic, citric, tartaric and toluenesulphonic.ALSO:Pharmaceutical compositions contain as active ingredient an ester of deserpidic acid in which both the hydroxyl and carboxyl groups are esterified (other than deserpidine itself for which see Specification 809,912), or a salt thereof. The compositions may be in solid or liquid dosage form for oral or parenteral administration, e.g. as tablets, powder, capsules, pills, solutions, emulsions or suspensions. They act as sedatives or hypotensive agents. The compositions may contain preservative, stabilizing wetting or emulsifying agents, salts for controlling osmotic pressure, buffers or other therapeutically active substances, e.g. 1-hydrazinophthalazine or reserpine. Specified ingredients are gelatine, lactose, starch, magnesium stearate, talc, vegetable oils, benzyl alcohol, ascorbic acid, gums, propylene glycol, polyalkylene glycols, petroleum jelly, cholesterol, tragacanth and alcohol. Preferred compounds are those in which the carboxyl group is esterified with a lower alkanol and the hydroxy group is esterified with a lower alkanol and the hydroxy group is esterified with an aromatic, araliphatic or heterocyclic acid, e.g. 3 : 4 : 5-trimethoxybenzoic, 3 : 4-dimethoxybenzoic, 4-methoxybenzoic, 2-furoic, nicotinic, 3 : 4 : 5-trimethoxy-cinnamic or 0-carbethoxy-syringaic; aliphatic acids such as acetic are, however, also suitable. Typical compounds are mentioned, as well as a number of inorganic and organic acids for salt formation.