Benzisochromanquinones from Ventilago goughii

From the acetone extract of the root bark of Ventilago goughii four new benzisochromanquinones, ventiloquinones L, M, N and O have been isolated. The structures of ventiloquinone-L as cis-9-hydroxy-7-methoxy-1,3-dimethyl-3,4,5,10-tetrahydro-1 H-naphtho[2,3- c] pyran-5,10-quinone, M as cis-6,9-dihydroxy-7,8-methylenedioxy-1,3-dimethyl-3,4,5,10-tetrahydro-1 H-naphtho[2,3- c] pyran-5,10-quinone, and O as 5,7(or 8,10-trihydroxy-8(or 7)-methoxy-6,9-dihydro-1 H-naphtho[2,3- c] pyran-6,9-quinone have been established from their spectral data. Possible dimeric structures for ventiloquinone N are discussed.