Crassiflorone, a new naphthoquinone from Diospyros crassiflora (Hien)

A new naphthoquinone, 11-hydroxy-1,9-dimethyl-6H-naphtho[2′,3′:4,5]furo[3,2-c]chromene-6,7,12-trione, named crassiflorone, was isolated from the stem bark of Diospyros crassiflora together with the known compounds plumbagin, cyclocanaliculatin, gerberinol, lupeol, lupenone and betulinic acid. The structures of the compounds were established on the basis of 1D and 2D NMR spectroscopic data, as well as co-TLC with authentic samples. Some of the above compounds exhibited significant antimicrobial activity against bacteria and yeasts.