Chaetoatrosin A, a novel chitin synthase II inhibitor produced by Chaetomium atrobrunneum F449

Chaetoatrosin A, a novel chitin synthase II inhibitor, was isolated from th e culture broth of fungus F449, which was identified as Chaetomium atrobrun neum F449. Chaetoatrosin A was purified by solvent partition, silica gel, O DS, preparative TLC, and Sephadex LH-20 column chromatographies, consecutiv ely. The structure of chaetoatrosin A was assigned as 1,8-dihydroxy-3(2-hyd roxypropionyl)-6-methoxynaphthalene on the basis of various spectroscopic a nalyses including UV, IR, mass spectral, and NMR. Its molecular weight and formula were found to be 262 and C14H14O5, respectively. Chaetoatrosin A in hibited chitin synthase II by 50% at the concentration of 104 mu g/ml in an enzyme assay system. This compound showed antifungal activities against Rh izoctonia solani, Pyricularia oryzae, Botrytis cinerea, Cryptococcus neofor mans and Trichophyton mentagrophytes.