N.G. Bisset

Tabernaemontana L. (Apocynaceae): A review of its taxonomy, phytochemistry, ethnobotany and pharmacology☆

The taxonomy, phytochemistry, ethnobotany, and pharmacology of the genus Tabernaemontana L. (Apocynaceae) is reviewed. The genus is currently being revised taxonomically; most of the segregate genera are being reunited with it and the number of species that will ultimately be recognized will probably be about 100. All the names encountered in the chemical and ethnobotanical literature have been evaluated as far as possible, and a list is presented of the recognized species and their synonyms. The biogenesis and classification of the indole alkaloids found in Tabernaemontana species is set out and some problems in the determination of their stereochemistry are discussed. To facilitate access to the information, three lists have been compiled: the alkaloids in alphabetical order; the alkaloids in order of increasing molecular weight; and the alkaloids grouped according to their biogenetic classification, together with the species and plant part(s) in which they are known to occur. Biogenetic and chemotaxonomic aspects are briefly considered. A table of the non-alkaloidal constituents is also included. The ethnobotany of individual Tabernaemontana species is outlined and an overall assessment made. Likewise, information on the pharmacology of crude extracts and individual alkaloids from Tabernaemontana species has been assembled and appraised.

Quaternisation and oxidation of strychnine and brucine during plant extraction

Abstract Use of CHCl 3 and CH 2 Cl 2 for the extraction of amines and alkaloids may easily lead to the formation of artifacts. CH 2 Cl 2 in particular reacts rapidly at laboratory temperature with strychnine and brucine forming quaternary salts. In connection with this, the TLC behaviour, NMR and MS properties of the chlorometho- and bromometho-halides and -picrates of strychnine and brucine are discussed. On standing, CHCl 3 solutions of strychnine yield not only a quaternary salt but also 16-hydroxystrychnine (pseudostrychnine) and strychnine N -oxide; brucine reacts similarly. When CH 2 Cl 2 and CHCl 3 are to be used for the extraction of amines or alkaloids, it is advisable to ascertain whether or not they leave the compounds chemically unchanged.

Angustine and related alkaloids from species of Mitragyna, nauclea, uncaria, and Strychnos

Abstract Angustine and related alkaloids have been identified in extracts from species of Mitragyna Korth., Nauclea L. Uncaria Schreb. (Rubiaceae), and from African and Asian species of Strychnos L. (Loganiaceae). The chemotaxonomic significance of the occurrence of these alkaloids is discussed.

Alkaloids and iridoids from Strychnos nux-vomica fruits

Abstract The alkaloid mixtures present in the fruit pericarp and fruit pulp of Strychnos nux-vomica L. are qualitatively very similar to that found in the seeds. In addition to alkaloids previously known to occur in this plant, small amounts of 4-hydroxystrychnine and the new base N-methyl- sec.-pseudo-β-colubrine have been isolated. Cantleyine, which is a non-indolic base and an artefact, has also been obtained. The iridoid mixture in the fruit pulp is predominantly loganin with small amounts of related compounds, including the biogenetically important secologanin.

Arrow poisons in south Asia. Part 1. Arrow poisons in ancient India.

Abstract The use of arrow poisons in ancient India is discussed. While it is possible that Mesolithic hunting communities may have applied poison to their arrows, passages in the R g Veda and Atharva Veda indicate its use in warfare. The meaning of the word āla, used in the R g Veda to denote the poison smeared on the arrowheads, is examined; but the available evidence, while almost certainly excluding a mineral (arsenical) source, does not allow a con- clusion to be drawn between an animal and/or plant origin. Certain hymns in the Atharva Veda point to aconite tubers as one source. Later Sanskrit (and Buddhist) literature shows that poisoned arrows continued to be used and that a second source of poison was (putrefying) snakes — a source confirmed by an account in the classical literature of Alexander the Greats campaign in western India. Detailed descriptions of the symptoms and methods of treatment of wounds caused by poisoned arrows are to be found in the Sanskrit medical literature

Alkaloids of Sri Lankan Strychnos nux-vomica

Abstract Twenty-two identified alkaloids have been isolated from the root bark and leaves of a Sri Lankan Strychnos species supplied as S. nux-vomica . T

Protostrychnine, a new alkaloid from Strychnos nux-vomica

Abstract The tertiary bases from a sample of Strychnos nux-vomica contain, as well as the expected strychnine and brucine, an unusually high proportion of 4-hydroxy and 4-hydroxy-3-methoxy compounds. The biosynthetic implications of the isolation of a new alkaloid, 12β,13α-dihydro-12α-hydroxyisostrychnine, named protostrychnine, are discussed.

Antirhine and antirhine metho-salt from the leaves of Strychnos camptoneura

Abstract The isolation of antirhine and antirhine metho-salt from the leaves of Strychnos camptoneura is described. The conformation of antirhine is discuss

Alkaloids from the leaves of Strychnos wallichiana

Abstract The leaves of Strychnos wallichiana Steud. ex. DC. from Bangladesh contain icajine and novacine as their major alkaloids. Smaller amounts of strychnine, brucine, pseudostrychnine, pseudobrucine, N -methyl- sec. -pseudo-β-colubrine, 14-hydroxyicajine, strychnine N -oxide, and brucine N -oxide are also present. The new bases 14 hydroxynovacine and icajine N -oxide have been isolated.

New alkaloids from Strychnos icaja

Abstract The alkaloids of Strychnos icaja (Loganiaceae) have been studied. An extract from Zaire leaf material yielded nine alkaloids, comprising novacine, the new base 21,22-α-epoxy-4,14-dihydroxy-3-methoxy- N -methyl- sec .-pseudostrychnine, and seven others of known structure previously obtained from the plant. Cameroun leaf material gave five alkaloids, of which one, 21,22-α-epoxy-3,4-dimethoxy- N -methyl- sec .-pseudostrychnine, is new. Fruits from Gabon afforded eight alkaloids; two of them are new and are formulated as 21,22-α-epoxy-4-methoxy- N -methyl- sec .-pseudostrychnine and the corresponding 14-hydroxy derivative.