Synthesis and in vitro antiproliferative evaluation of some ring B abeo-sterols.

Using cholesterol, β-sitosterol, dehydroisoandrosterone and pregnenolone as starting materials, a series of 5(6→7)abeo-sterols with different substituted groups and various side chains were synthesized and the antiproliferative activity of these compounds against HeLa, SMMC 7404 and MGC 7901 cells was investigated. The results revealed that the presence of a cholesterol-type side chain was very important for their cytotoxicity, and in particular a thiosemicarbazone at the C-6 position significantly enhanced the antiproliferative activity of these compounds. Although the elimination of 5-hydroxyl has no an obvious effect on their cytotoxic function, removal of the hydroxyl at the C-3 position decreased markedly the antiproliferative activity of the compounds. Some compounds have similar cytotoxic capability as cisplatin does.