Synthesis of Novel Spin‐Labeled Derivatives of Podophyllotoxin as Potential Antineoplastic Agents

Abstract

Five novel nitroxyl spin‐labeled ester derivatives of podophyllotoxin have been prepared by reacting the corresponding N‐(1‐oxyl‐2,2,6,6‐tetramethyl‐4‐piperidinyloxycarbonyl) amino acids with the hydroxy group of podophyllotoxin in the presence of dimethylaminopyridine and N,N‐dicyclohexylcarbodiimide and evaluated as potential antitumor agents. All of the target compounds showed more significant cytotoxicity against P‐388 murine leukemia and A‐549 human lung carcinoma in vitro than etoposide.