.beta.-Sitosterol carboxymethylthiosuccinate NSC110372 Pfizer Sitosterol Stigmast-5-en-3-ol, hydrogen 2(or 3)-[(carboxymethyl)thio]butanedioate, (3.beta.)- Succinic acid, [(carboxymethyl)thio]-, 1-stigmast-5-en-3.beta.-yl ester Succinic acid, [(carboxymethyl)thio]-, 4-stigmast-5-en-3.beta.-yl ester or