Isocoumarin from Paepalanthus bromelioides

Abstract The new isocoumarin, 9,10-dihydroxy-5, 7-dimethoxy-1H-naphtho(2,3 c )pyran-1-one, was isolated from the capitula of Paepalanthus bromelioides . The structure was established by means of the spectral data of the natural product and its derivatives. The natural isocoumarin isolated has strong antibiotic activity.