Microwave-enhanced synthesis of 26-amino-22-oxocholestanes and their cytotoxic activity

[Display omitted] •26-amino-22-oxocholestanes were synthesized from diosgenin.•MW heating provided the best yields and reaction times.•4-aminourazole yielded the 26-iminourazole-22-oxocholestane.•Two 26-aminosteroids showed cytotoxic activity on SiHa and MCF-7 cancer cells. The synthesis of a series of 26-amino-22-oxocholestanes derived from diosgenin was accomplished via the substitution of an iodine atom at C-26 by primary and secondary amines. The reactions were conducted in refluxing acetonitrile and through microwave-assisted heating. The latter shows significant improvements in terms of reaction times going from hours to a few minutes or even seconds for completion. Only one of the selected amines, 4-aminourazole, did not yield the substitution product and the imine formation pathway was investigated instead, achieving the 26-iminourazole-22-oxocholestane. All the final products have been characterized and the cytotoxic activity of three of them has been evaluated in SiHa, MCF-7 and MDA tumor cell lines by the sulforhodamine B assay.