Antitumor Activity of the R- and S-Enantiomers of RS-2-[[Hydroxy[[2-[(octadecyloxy)methyl]tetrahydrofuran-2-yl]methoxy]phosphinyl]oxy]-N,N,N-trimethylethylaminium Hydroxide Inner Salt

The R- and S-enantiomers of 2-[[hydroxy[[2-[(octadecyloxy)methyl]tetrahydrofuran-2-yl]methoxy]phosphinyl]oxy]-N,N,N-trimethylethylaminium hydroxide salt (SRI 62-834) have been evaluated in several assays to determine potential antitumor activity. The S-enantiomer showed slightly greater cytotoxic activity than the R- or RS-forms against several murine tumor cell lines. In the mouse Meth A fibrosarcoma model, the S-enantiomer was ca. 4 times more effective than the R-isomer in controlling the size of tumor growth and increasing the number of survivors.