Despite the major advances of cancer chemotherapy during the past 40 years, host toxicities and drug resistance justify the need to continue the search for new antineoplastic agents. In the present work, we have studied the effect of six synthetic drugs on the in vitro growth of two murine mammary adenocarcinomas (M3 and MM3), as well as on normal embryonic cells. AI, MIC and MPI are purines coupled to a sulfonylated inositol, while DIC and DEI have nitrogen mustard as substituent. Methylsulfonylmucoinositol was the common substituent. Our results indicated that only drugs substituted with nitrogen mustards had an antiproliferative effect. DEI was more effective on tumor cells than on normal cells.