Source:http://linkedlifedata.com/resource/umls/id/C0282532
MSH: A class of drugs that differs from other alkylating agents used clinically in that they are monofunctional and thus unable to cross-link cellular macromolecules. Among their common properties are a requirement for metabolic activation to intermediates with antitumor efficacy and the presence in their chemical structures of N-methyl groups, that after metabolism, can covalently modify cellular DNA. The precise mechanisms by which each of these drugs acts to kill tumor cells are not completely understood. (From AMA, Drug Evaluations Annual, 1994, p2026),NCI: An antineoplastic agent that replaces hydrogen atom(s) in nucleophilic moieties with alky radical(s), hindering proper function. Alkylating agents exhibit cytotoxic effects through the alkylation of DNA, resulting in strand cross-linking, ultimately inhibiting DNA replication and cancer cell growth.