Biological activities of synthetic triterpenoid and steroid beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranosides

Heterocyclizations of pregnenolone: novel synthesis of thiosemicarbazone, thiophene, thiazole, thieno[2,3-b]pyridine derivatives and their cytotoxicity evaluations

Pregnenolone (1) was used as a template to develop new anticancer compounds. Ring D modification of 1 through its reaction with 4-phenyl-3-thiosemicarbazide gave the thiosemicarbazone derivative 3. The latter compound underwent heterocyclization reactions to give the thiazolyl hydrazonoandrostane and pyrazolyl semicarbazidoandrostane derivatives 5a-d, and 9a-d, respectively. On the other hand compound 1 reacted with either malononitrile or ethyl cyanoacetate to give the Knoevenagel condensated products 11a and 11b, respectively. Compounds 11a,b afforded the thiophenyl pregnane derivatives 12a and 12b, respectively, their reactivity toward some chemical reagents was studied. The cytotoxicity of the newly synthesized heterocyclic steroids against three human tumor cell lines namely breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS cancer (SF-268) were studied. Some of tested compounds were found to exhibit much higher inhibitory effects toward the three tumor cell lines than the reference drug, doxorubicin.

Exploration of the correlation between the structure, hemolytic activity, and cytotoxicity of steroid saponins

The hemolytic activity of a collection of 63 steroid saponins was determined. The correlations between these structures and their hemolytic and cytotoxic activities are discussed. It has been demonstrated that the hemolytic activity of steroid saponins is highly dependent on their structures, that is, the sugar length, the sugar linkage, the substitutes on the sugar, as well as the aglycone. It has also been disclosed that the hemolytic activity and cytotoxicity of steroid saponins are not correlated. These results suggest that steroid saponins execute hemolysis and cytotoxic activity in different mechanisms, and encourage to develop steroid saponins into potent antitumor agents devoid of the detrimental effect of hemolysis.