Taking orostanal (a compound from a Japanese marine sponge, Stelletta hiwasaensis) as a lead compound, some novel B-norcholesteryl benzimidazole and benzothiazole derivatives were synthesized. The antiproliferative activity of the compounds against human cervical carcinoma (HeLa), human lung carcinoma (A549), human liver carcinoma cells (HEPG2) and normal kidney epithelial cells (HEK293T) was assayed. The results revealed that the benzimidazole group was a better substituent than benzothiazole group for increasing the antiproliferative activity of compounds. 2-(3β′-Acetoxy-5β′-hydroxy-6′-B-norcholesteryl)benzimidazole (9b) with the structure of 6-benzimidazole displays the best antiproliferative activity to the cancer cells in all compounds, but is almost inactive to normal kidney epithelial cells (HEK293T). The assay of compound 9b to cancer cell apoptosis by flow cytometry showed that the compound was able to effectively induce cancer cell apoptosis. The research provided a theoretical reference for the exploration of new anti-cancer agents and may be useful for the design of novel chemotherapeutic drugs.
Ozonolysis of cholesterol and other Δ5-steroids in the presence of alcohols: a revised mechanism and hydroperoxide structure of the solvent-participated product, confirmed by X-ray analysis
作者:Zdzisław Paryzek、Urszula Rychlewska
DOI:10.1039/a702633a
日期:——
The structure of the product formed in the course of the reaction of cholesterol acetate and other Δ5-steroids with ozone in alcohol-containing solvents has been revised. The solvent-participated products are hydroperoxides, 5α-hydroperoxy-7α-alkoxy-5α-B-homo-6-oxasteroids 3 and not the previously claimed cyclic hemiperacetals, 5α-hydroxy-7a-alkoxy-B-dihomo-6,7-dioxacholestane derivatives 1. The final