Viburspiran, an antifungal member of the octadride class of maleic anhydride natural products

摘要

Viburspiran (8), a structurally new member of the maleic anhydride natural products, was isolated, along with seven known compounds 9-15, from the fungal endophyte Cryptosporiopsis sp. The structure of the new compound was elucidated by spectroscopic methods and confirmed by single-crystal X-ray analysis. The absolute configuration was established by TDDFT CD calculations by using the solid-state structure for input geometry. Viburspiran (8) is the first representative of a new class of eight-membered maleic anhydride natural products, named octadrides and exhibited antifungal activity against Botrytis cinerea and Microbotryum violaceum. Viburspiran (8), the first representative of a new class of eight-membered maleicanhydride natural products, named octadrides, was isolated from the fungal endophyte Cryptosporiopsis sp. The structure was confirmed by single-crystal X-ray analysis and the absolute configuration established by TDDFT CD calculations. Viburspiran (8) exhibited antifungal activity against Botrytis cinerea and Microbotryum violaceum.