Five new metabolites, palmarumycin M1 (1a) and M2 (3), papyracillic acid C (6) and the microsphaeropsins A (7) and B (8) were isolated from the fungus Microsphaeropsis sp. together with the known decaspirone (2) and the papyracillic acids A and B (4 and 5). Their structures were determined by means of spectroscopic data including HREIMS, 1H NMR, 13C NMR, 2D NMR (HMQC, HMBC, NOESY) and X-ray single crystal analysis. The absolute configuration of palmarumycin M1 (1a) was determined by single-crystal X-ray analysis of the bis(4-bromobenzoate) 1c and the relationship between 1a, 2 and 3 established by chemical transformation of 1a into 2 and of 3 into 2. The relative configuration of papyracillic acids A–C (4–6) was revised and their absolute configuration determined by comparison of TDDFT-calculated and experimental solid-state CD spectra.
Metabolic Products of the endophytic Fungus Microsphaeropsis sp. from Larix decidua
PESCITELLI, GENNARO;
2007-01-01
Abstract
Five new metabolites, palmarumycin M1 (1a) and M2 (3), papyracillic acid C (6) and the microsphaeropsins A (7) and B (8) were isolated from the fungus Microsphaeropsis sp. together with the known decaspirone (2) and the papyracillic acids A and B (4 and 5). Their structures were determined by means of spectroscopic data including HREIMS, 1H NMR, 13C NMR, 2D NMR (HMQC, HMBC, NOESY) and X-ray single crystal analysis. The absolute configuration of palmarumycin M1 (1a) was determined by single-crystal X-ray analysis of the bis(4-bromobenzoate) 1c and the relationship between 1a, 2 and 3 established by chemical transformation of 1a into 2 and of 3 into 2. The relative configuration of papyracillic acids A–C (4–6) was revised and their absolute configuration determined by comparison of TDDFT-calculated and experimental solid-state CD spectra.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
