title: [Studies on total syntheses of cytotoxic cyclic peptides of marine origin].
abstract: Cyclic peptides from marine organisms constitute a growing class of naturally occurring cytotoxic substances. A general synthetic method for thiazole amino acids, common components of these cyclic peptides 1-7, has been developed and total syntheses of 1-7 have been achieved. In the process, dolastatin 3 with the proposed structure has been disclosed to differ from the natural material and the real structure 2 has been confirmed by its total synthesis. Patellamides with the proposed structures has been revised to be 6 by their total syntheses. Absolute configuration of ascidiacyclamide has been determined to be 4 and the structure of ulithiacyclamide has been confirmed. Ulicyclamide has been efficiently prepared in combination with solid and liquid phase syntheses. Didemnins A and B, cyclic depsipeptides with potent antitumor activity, have been prepared by condensation of the key eastern and western fragments.
authors.affiliation: Faculty of Pharmaceutical Sciences, Nagoya City University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hamada
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents; D008387:Marine Toxins / Q000138:chemical synthesis* / Q000494:pharmacology; D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D008387:Marine Toxins; D010455:Peptides