title: Cysteine derivatives with reactive groups as potential antitumor agents.
abstract: Cysteine derivatives having diazo ketone and chloro ketone functions have been prepared. In order to effect adequate protection for modifying the carboxyl group, cysteine was converted to a thiazolidine derivative I, which was then converted to the N-acetyl derivative VII. The active ester method or activation with DCC yielded the diazo ketone derivative VIII. Similar treatment of the parent compound I with DCC led to a self-condensation reaction giving a diketopiperazine VI. The diazo ketone derivative VIII has been used in preparing alpha-chloro ketone derivative X and a homologue of cysteine. Deblocking N-acetylated thiazolidine derivatives with various reagents did not proceed satisfactorily. Interaction of the N-acetylated blocked ester XII with trifluoroacetic acid opened the thiazolidine ring to give the N-acetylated blocked diester XIII and other products. The chloro ketone derivative X was found to have a moderate inhibitory activity against mouse mammary adenocarcinoma in cell culture. S-(1-Adamantyl)-L-cysteine was prepared and was found to be inactive.
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D003545:Cysteine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D003864:Depression, Chemical; D005260:Female; D066298:In Vitro Techniques; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism; D051379:Mice
chemical_list: D000970:Antineoplastic Agents; D003545:Cysteine