Synthesis and evaluation of some steroidal oximes as cytotoxic agents: Structure/activity studies (II)

Hydroximinosteroids isolated from marine sponges display a variety of biological functions including cytotoxicity and anti-virus. In this study, we synthesized a series of hydroximinosteroid derivatives with a different functional group on the ring A or B and various side chains at position 17, and analyzed the cytotoxicity of these compounds against sk-Hep-1, H-292, PC-3 and Hey-1B cancer cells. Our results revealed that although a cholesterol-type side chain at position 17 is required for the biological activity of the compounds as we previously confirmed, elimination of the 4,5-double bond augmented the cytotoxic activity for the steroidal oximes. In addition, the presence of a hydroxy on 3- or 6-position of the steroidal nucleus resulted in a remarkable increase of cytotoxic activity. Our findings present more evidence showing the relationship between the chemical structure and biological function.