7-Chloro-4,6-dimethoxy-1(3H)-isobenzofuranone and basidalin: antibiotic secondary metabolites from Leucoagaricus...

Two antibiotic metabolites were isolated from cultures of Leucoagaricus carneifolia. Their structures were elucidated by spectroscopic methods. The first compound, 7-chloro-4,6-dimethoxy-1(3H)-isobenzofuranone [corrected] (1) had to our knowledge not been described from natural sources whereas the second, basidalin (2), is a known metabolite of L. naucina (H. Iinuma et al., 1983). 1 exhibits antibiotic activities with minimal inhibitory concentrations of 20 micrograms/ml against Botrytis cinerea, the most sensitive microorganism.