Alkaloids of the roots of Desmodium gangeticum

Abstract

Previously, the occurrence of several simple indolic bases in the aerial portions of Desmodium gangeticum D.C. (Leguminosae : Papilionaceae) was reported by us.lSince the roots of this species find use in the ayurvedic system of medicine,= we have now investigated their alkaloidal constituents. The present communication describes the isolation and identification of seven alkaloids representing three structural types, viz. carboxylated and decarboxylated tryptamines, and ,B-phenylethylamine. The bases identified are: N,N-dimethyltryptamine, its N,-oxide, hypaphorine, hordenine, candicine, N-methyltyramine, and P-phenylethylamine. I n addition, the presence of an apparently new P-phenylethylamine alkaloid was also detected. Preliminary findings indicated that the last-mentioned alkaloid is related to halostachine, a ,B-hydroxy-,B-phenylethylamine alkaloid occurring with tryptamines in the Chenopodiaceae.3VC7hile co-occurrence of P-phenylethylamines and simple indolic bases has been known in the genus Acacia4 (Leguminosae : Mimosae), the quaternary P-phenylethylamine base, candicine, appears to have been isolated only from the Argentine c a~t u s .~ Further, the previous results1 indicated that the elaboration of alkaloids by Desmoclium gangeticum had not been restricted to the "proto alkaloids" (alkamine~)~ only, since this species also contained two P-carboline alkaloids in its aerial portions.This alkaloid versatility of D. gangeticum obviously suggests it to be a phylogenetically complex species in the subfamily Papilionaceae, different from those6 producing either the carboxylated or decarboxylated tryptamines or the ,B-phenylethylamines.Some of the curative properties ascribed2 to the root extracts of D. ga.ngeticum seem to be due to the major alkaloid, hordenine, which is known to increase the flow of urine and is a remedy for diarrhoea and dysentery.7 Pharmacological evaluation of the species is currently being done in this laboratory.

Accumulation of an Aromatic Amine, β-Phenethylamine, in Root Nodules of Adzuki Bean Vigna angularis

“…These reactions, catalyzed by the aromatic amino acid decarboxylase (E.C.4.1.1.28), are commonly the first step in the biosynthesis of many important alkaloids (Berlin and Fecker, 2000;Facchini and DeLuca, 1995;Gu¨gler et al, 1988;Marques and Brodelius, 1988). b-Phenethylamine (b-PHA), the decarboxylated form of phenylalanine, has formerly been reported as the usual component of alkaloids in cactus (Keller et al, 1973;Mata and McLaughlin, 1980) and in perennial legume trees such as Alhagi pseudalhagi , Prosopis nigra (Moro et al, 1975), and many species of Desmodium (Ghosal and Banerjee, 1969;Ghosal et al, 1972;Ghosal and Mehta, 1974) and Acacia (Camp and Norvell, 1966;Fitzgerald, 1964). Tissue extracts of these plant species generally contain a variety of b-PHA derivatives (e.g., mescaline, N-methyl-b-PHA, and hordenine), often referred to as PHA alkaloids, which show sympatho-mimetic properties, psychic effects, and other versatile pharmacological actions on higher animals Kapadia and Fayez, 1970;Smith, 1977a).…”

Efficacy of Desmodium gangeticum extract and its fractions against experimental visceral leishmaniasis

“…Total alkaloids of this species showed smooth muscle stimulant, anticholinesterase, CNS stimulant and depressant responses (Ghosal and Bhattacharya, 1972). Chemical investigations have revealed that this plant contains alkaloids like tryptamines, phenethylamines, and their N-oxides (Ghosal and Banerjee, 1969); pterocarpanoids like gangetin, gangetinin, desmodin, and desmocarpin (Purushotaman et al, 1971(Purushotaman et al, , 1975Ingham and Dewick, 1984); phospholipids (Rastogi et al, 1971), sterols such as 24-ethylcholesta-5, 22-diene-3␤-ol; 24-ethylcholest-5-en-3␤-ol and 24-methylcholest-5-en-3␤-ol (Mukat and Varshney, 1986), flavone glycosides such as 4 ,5,7-trihydroxy-8-prenylflavone-4 -O-␣-l-rhamnopyranosyl-(1-6)-␤-d-glucopyranoside and 8-C-prenyl-5,7,5 -trimethoxy-3 ,4 -methylenedioxy flavone (Yadava and Reddy, 1998;Yadava and Tripathi, 1998).…”

THE ACTIVE PRINCIPLES OFALHAGI PSEUDALHAGI:β–PHENETHYLAMINE AND TETRAHYDROISOQUINOLINE BASES

“…light petrol. The identity , of the alkaloids was established by co-TLC with authentic markers (GHOSAL and BANERJEE, 1969;GHOSAL et al, 1972;, by their chemical transformation into known compounds, where possible, and from correspondence of melting point,optical rotation, UV, PMR, and MS of the alkaloids and their derivatives with those reported in the literature (KAPADIA and FAYEZ, 1970;SPAIR et al, 1970;. T h e petrol.…”

“…It showed TLC behavior, colour reactions, and UV absorption maxima characteristic of N-methyltyramine (GHOSAL and BANERJEE, 1969). T h e minor component, from the aforementioned preparative layer chromatography, was obtained as a brown gum (11 mg).…”