title: Synthesis and antitumor activity of 20(S)-camptothecin derivatives: A-ring modified and 7,10-disubstituted camptothecins.
abstract: 20(S)-Camptothecin derivatives having nitro, amino, chloro, bromo, hydroxyl and methoxyl groups in the A-ring were synthesized. B-Ring hydrogenated camptothecin (2a) was converted into 10-hydroxycamptothecin (6e) by treatment with lead tetraacetate in trifluoroacetic acid. 10-Substituted derivatives (6) were obtained by a photoreaction of N-oxides (9). The cytotoxicity of the A-ring modified camptothecins was evaluated against KB cells in vitro and leukemia L1210 in mice. 7-Ethyl-10-hydroxycamptothecin (6i) was identified as a potential derivative for further modification.
authors.affiliation: Yakult Central Institute for Microbiological Research, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Sawada
authors.forename: S
authors.initials: S
authors.lastname: Matsuoka
authors.forename: K
authors.initials: K
authors.lastname: Nokata
authors.forename: H
authors.initials: H
authors.lastname: Nagata
authors.forename: T
authors.initials: T
authors.lastname: Furuta
authors.forename: T
authors.initials: T
authors.lastname: Yokokura
authors.forename: T
authors.initials: T
authors.lastname: Miyasaka
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D006801:Humans; D007624:KB Cells / Q000187:drug effects; D007939:Leukemia L1210 / Q000188:drug therapy; D051379:Mice; D008815:Mice, Inbred Strains
chemical_list: D000970:Antineoplastic Agents; D002166:Camptothecin