Botcinins E and F and Botcinolide from Botrytis c inerea and Structural Revision of Botcinolides

• Published in: Journal of natural products (Washington, D.C.) D.C.), 2006-04, Vol.69 (4), p.722-725
• Main Authors: Tani, H, Koshino, H, Sakuno, E, Cutler, H. G, Nakajima, H
• Format: Article
• Language: English
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np060071x

Botcinins E and F were isolated together with the known botcinolide. The structures of botcinins E and F were determined to be 3-O-deacetylbotcinin A (5) and 3-O-deacetyl-2-epi-botcinin A (6), respectively, by spectroscopic methods and chemical conversion. The structure of botcinolide was revised on the basis of spectroscopic data and chemical conversion. Botcinolide was originally reported as a nine-membered lactone (7), but the revised structure is the seco acid of botcinin E (13). Thus botcinolide is renamed botcinic acid, and homobotcinolide is renamed botcineric acid. Reinvestigation of the spectroscopic data reported for all botcinolide analogues indicates that 4-O-methylbotcinolide and 3-O-acetyl-2-epibotcinolide are the same as a methyl ester of botcinic acid (13a) and botcinin A (1), respectively, and that 2-epibotcinolide may be the same as botcinin E (5). Compounds 5, 6, and 13 showed weak antifungal activity against Magnaporthe grisea, a pathogen of rice blast disease.