Lloydia最新文献

A total of 47 plant extracts representing 132 genera and 172 species of plants distributed over 59 families were collected from various parts of Nigeria. The plant extracts were screened for the presence of alkaloids, saponins, tannins, phlobatannins and anthraquinones. The number of positive tests obtained was 176 (32.18%) for alkaloids, 242 (44.24%) for saponins, and 435 (79.52) for tannins. A few were positive for phlobatannins and anthraquinones.

The roots of T. minus race B have yielded 9 alkaloids, thalirabine (1), thaliracebine (13), thalfine (19), thalfinine (20), thalrugosaminine (22), thalidasine (13), obaberine (24), thaliglucinone (25) and (S)-reticuline (26). The first two, possessing marked hypotensive activity, were assigned complete structures by physical and chemical methods. Thalfine (19) was given S-configuration at its one asymmetric center and was converted to thalfinine (20) and epithalfinine (21), thus the stereochemistry was established at one of the two optically active positions. The other alkaloids were identified by direct comparison with known samples. Antimicrobial testing showed thalirabine, thaliracebine, thalfine, and thalfinine to be active against Mycobacterium smegmatis.

An accidental case of mushroom poisoning led to the detection of psilocybin in Gymnopilus validipes (Cortinariaceae). This compound was subsequently isolated (0.12% yield) by anion exchange and cellulose chromatography. Eighteen additional species of Gymnopilus were screened by a method capable of detecting 0.0004% psilocybin in dried carpophores. Psilocybin was detected in G. aeruginosus, G. luteus, G. viridans and G. spectabilis. The latter species has been previously reported to be hallucinogenic. This is the first report of psilocybin from this genus.

The antimicrobial activities of a number of cytotoxic C-benzylated flavonoids from Uvaria chamae have been determined. The minimum inhibitory concentration values of these flavonoids and certain of their derivatives against Straphylococcus aureus, Bacillus subtilis, and Mycobacterium smegmatis compare favorably with those of streptomycin sulfate.

The antimicrobial activity seen in extracts of Hunnemmania fumariaefolia S. resides in the alkaloids. The activity seen in the non-polar fractions had been shown by chromatography, physicochemical measurements, and comparisons with authentic samples to be due to apparently artifactual formation of the pseudomethanolates and pseudoethanolates of the alkaloids sanguinarine and chelerythrine, which are abundant in the plant. The enhanced potency of the pseudoalcoholates of sanguinarine over the parent benzophenanthridine is discussed in comparison with the in vitro biopotencies of other analogs prepared for the purpose. It appears that the pseudoalcoholates may be useful prodrugs.

The desert-marigold Baileya multiradiata Harv. and Gray (Compositae) has been found to produce a series of sesquiterpenes that markedly inhibit growth of the murine lymphocytic leukemia P388 and the corresponding in vitro cell line. Separation guided by bioassay led to the isolation of baileyin (1), fastigilins B and C (3a and 2a), radiatin (3b), pleniradin (4a), and the new pseudoguaianolide multiradiatin (2b). The most significant antitumor activity was displayed by fastigilin C (2a) and radiation (3b).

Investigations into diseases in cattle grazing on grass pastures infected with clavicipitaceous fungi have resulted in the isolation and characterization of erythro and threo 1-(3-indolyl) propane-1,2,3-triol from cultures of Balansia epichloë (Weese). Gas chromatography-mass spectroscopy analyses of synthetic and natural epimers as their trimethylsilyl derivatives is described. Toxicity studies with fertile chicken eggs demonstrated that the threo epimer was the more active compound. The ratio of erythro to threo was calculated at 3:2 in the natural isolate.

Two supposedly Strychnos-based Semai Senoi dart poisons from Western Malaysia, ipoh akar and lampong, and their accompanying plant materials have been re-investigated botanically, chemically, and pharmacologically. The two poisons contained tertiary and quaternary alkaloids, including strychnine and bis-quaternary dimeric bases, and also cardiotonic glycosides. The dominant pharmacological activity of the highly toxic ipoh akar poison was convulsant. The weaker lampong poison had muscle-relaxant activity of the curarizing type. The alkaloids of the two poisons were almost certainly derived from Strychnosignatii Berg. (S. ovalifolia Wall. ex G. Don) and not from S. vanprukii Craib to which the accompanying plant materials probably belong, while the cardiotonic glycosides of the two poisons came from Antiaris toxicaria Lesch. The quaternary alkaloids of both S. ignatii and S. vanprukii have muscle relaxant activity.