Antitumor activity of a piperidine phospholipid

A piperidine phospholipid ((+/-)-2-[hydroxy] [1-octadecyloxycarbonylpiperidin-3-yl]methoxy-phosphinyl] oxy]-N,N,N, trimethylethaniminium hydroxide inner salt, SDZ 62-826) has been prepared that exhibited weak direct cytotoxicity and strong macrophage-induced cytotoxicity in vitro against a variety of murine and one human tumor cell lines. This compound was found to be as effective as ET-18-OCH3 and SRI 62-834, phospholipids with both strong direct and macrophage-induced cytotoxicity, in increasing survivors and reducing tumor volume when given either orally or intravenously in the mouse MethA fibrosarcoma model. These findings suggest that the macrophage-induced cytotoxicity exhibited by ET-18-OCH3 and other phospholipids may play an important role in this tumor model.