Preparation and cytotoxic evaluation of new steroidal oximes and aza-homosteroids from diosgenin and cholesterol

•Straightforward access to steroidal oximes at B-ring with a variety of side chains.•Synthesis of novel A/B-homolactams were obtained from cholesterol or diosgenin.•Selective cytotoxicity against MCF-7 cells was achieved (low micromolar range). Using cholesterol and diosgenin as starting materials, we have designed a straightforward methodology to prepare in a reduced number of steps a novel series of steroidal oximes and their aza-homolactam analogs with four types of side chains: cholestane, spirostane, 22-oxocholestane and 22,26-epoxycholestene. The products were evaluated for their cytotoxic activity against the MCF-7 breast cancer cell line. Moreover, the selectivity of the most active compounds was determined against peripheral blood lymphocytes. Compounds 5, 8 and 13 were found to be the most active derivatives, exhibiting IC50 values in the low micromolar range (7.9–9.5 µM) and excellent selectivities (IC50 > 100 µM) against the non-tumor cell line.