Botcinins E and F and Botcinolide from Botrytis cinerea and Structural Revision of Botcinolides

Abstract

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.

Natural occurrence, biological activities and synthesis of eight-, nine-, and eleven-membered ring lactones

“…80 A homologue of botcinolide, called homobotcinolide (121a), was isolated by these authors in 1996. 81 The isolation of other botcinolide derivatives was also reported by Collado et al 82,83 Tani et al 84 reinvestigated the spectroscopic data reported for botcinolide and some derivatives, and revised their structures (Figure 1). They found that botcinolide, originally reported as the ninemembered lactone 120a, is in fact the seco acid of botnicin E, as well as the structure of 2-epibotcinolide (122a) was revised as being the same as that of botcinin E (122b).…”

Two new botcinin derivatives encountered in the studies of secondary metabolites from the marine-derived fungus Botryotinia sp. SF-5275

“…The structures of previously known 1, 1a and 2 (Figure 1) were elucidated by analysis of NMR and MS data, together with comparison of their spectral data with those in the literature. [8][9][10] In the course of biological and chemical studies of these compounds, the instability of botcinin A (1) in methanol solution was …”

“…The structures of previously known 1, 1a and 2 ( Figure 1) were elucidated by analysis of NMR and MS data, together with comparison of their spectral data with those in the literature. [8][9][10] In the course of biological and chemical studies of these compounds, the instability of botcinin A (1) in methanol solution was recognized, and the transformation of compound 1 was monitored in methanol over several days at room temperature by HPLC analysis (Supplementary Information). In this analysis, compound 1 was shown to be slowly converted to previously known 3-O-acetylbotcinic acid methyl ester (1a) and botcinin D (1b), which were identified upon isolation and subsequent structural analysis.…”

“…12,13 Botcinins are unusual bicyclic lactones containing a g-hydroxy-a,bunsaturated carboxylic acid, unit with an aliphatic alkyl chain, and were originally isolated from Botrytis cinerea as antifungal agents. 8,9,14 These compounds have been targets of asymmetric total synthesis, 15,16 and the structure revision of boticinolides, previously reported as nine-membered lactones, to botcinin-type structures has been proposed. 9 In the study described here, PTP1B inhibitory effects of botcinins and related compounds were identified for the first time, and the chemical instability of botcinins A and B in methanol solution was recognized, leading to the identification of two new botcinin derivatives.…”

Micro-organismos de interesse farmacêutico e agrícola: estudo químico e biossintético

“…Na infecção acometida por este fungo necrotrófico, a planta hospedeira é bombardeada por numerosas enzimas extracelulares e metabólitos secundários, importantes para o fungo durante o processo de infecção, induzindo a clorose e/ou rompimento da parede celular (COLMENARES et al, 2002;ELAD et al, 2004;CHOQUER et al, 2007 (FEHLHABER et al, 1974;BREITMAIER, 1979;COLMENARES et al, 2002;TANI et al, 2005TANI et al, , 2006REINO et al, 2006;MORAGA et al, 2011). Durante doze dias foi realizado o acompanhamento da produção de sesquiterpenos da classe dos aristoloquenos nos extratos obtidos da biomassa micelial e do líquido fermentado.…”