[formula: see text] A novel pentacyclic polyhydroxylated sterol, xestobergsterol A (1a), has been synthesized in 24 steps and in good overall yield from stigmasterol 17. The key steps of the synthesis are the Breslow remote functionalization of the polyoxygenated steroid derived from 25 and the base-catalyzed epimerization-aldol condensation of the dione derived from 27.

THE study of the antirachitic activity induced in various sterols by irradiation, which led to the discovery of ergosterol as the most potent source of vitamin D [Rosenheim and Webster, 1926; 1927, 1], has subsequently brought to light an interesting relationship between chemical structure and potential biological activity. The most characteristic general features of the sterol structure are th...

Butea monosperma popularly known as Flame of the Forest, Dhak, Palash or ‘Bastard teak’ which has immense potential and appears to have a broad spectrum of activity on several ailments. Previous phytochemical examination of this plant indicated the presence of various constituents some of these are Cajanin and isoformononetin; Stigmasterol; Butin; two known flavonoids, isobutrin (3, 4, 2', 4'-t...

Gracilariopsis Persica (Rhodophyta) is one of the most abundant algae, introduced newly from the Indian Ocean. In this study, the main sterols of the algae have been isolated and identified. Separation and purification of the compounds was carried out on silica gel and sephadex LH20 column chromatography (CC) and high performance liquid chromatography (HPLC) to obtain five pure compounds 1-5. S...

Setaria megaphylla (Steud) Dur & Schinz (Poaceae), a grass used ethnomedically by herbalists in Nigeria for the treatment of diabetes was evaluated antidiabetic, hypolipidemic and pancreas protective potentials rats. Solvents fractions (hexane, dichloromethane (DCM), ethyl acetate (EA) methanol ) were investigated alloxan-induced diabetic Glibenclamide as positive control. The fasting blood glu...

Mycoplasma gallisepticum was adapted to grow with delta 5-sterols modified in the aliphatic side chain, and stopped-flow kinetic measurements of filipin association were made to estimate the sterol distribution between the two leaflets of the membrane. Cholesterol derivatives with unsaturated side chains (desmosterol, cis- and trans-22-dehydrocholesterol, and cholesta-5,22E,24-trien-3 beta-ol) ...

Ostreolysin, a cytolytic protein from the edible oyster mushroom (Pleurotus ostreatus), recognizes and binds specifically to membrane domains enriched in cholesterol and sphingomyelin (or saturated phosphatidylcholine). These events, leading to permeabilization of the membrane, suggest that a cholesterol-rich liquid-ordered membrane phase, which is characteristic of lipid rafts, could be its po...

Normal and reversed phase chromatographic purification of the chloroform soluble fraction of the methanolic extract of Tribulus longipetalus led to the isolation of a new tyramine amide, longipetalamide (1), two new benzocoumarins, longipetalasin A (8-n-propyl-threo-1S,2S-dihydroxy-5-methoxy-5a,9abenzocoumarin; 2) and B (8-n-propyl-threo-1S,2S-dihydroxy-5,10-dimethoxy-5a,9a-benzocoumarin; 3...

The aim of the present work is the evaluation of anti cancer effect of Carica papaya aerial parts extracts and also the investigation of the phytoconstituents from the extracts of the plant. Petroleum ether (40-60C), Chloroform, ethyl acetate and methanol 80% extracts of C. papaya aerial parts were tested for their anti cancer activity on three cancer cells TK10 (renal), UACC62 (melanoma) and M...