New flavans isolated from the leaves and stems of Cratylia mollis (Leguminosae)

Abstract Cratylia mollis Mart ex. Benth is a species belonging to the Leguminosae family that exists throughout South America, and it is one of the most abundant plants in northeastern Brazil, especially in the semiarid region. This plant is popularly known as “camaratu” and “camaratuba”, and the leaves and stems of this species are used as a substitute for cattle's alimentation during the dry season. The chemical investigation of the methanolic extract from leaves and stems of C. mollis led to the isolation of new flavans named 4,2′,3′-trihydroxy-4′-methoxy-6,7-(methylenedioxy) isoflavan, 7,2′-dihydroxy-6-methoxyflavan, 7,3′-dihydroxy-6,2′-dimethoxyflavan, 7-hydroxy-6-methoxyflavan, 2′-hydroxy-6,7-(methylenedioxy) flavan, 2 R *,3 S *-7,2′-dihydroxy-6-methoxy-flavan-3-ol, and 2 R *,3 S *-7,3-dihydroxy-6,2′-dimethoxyflavan-3-ol and an unusual flavan (11H-benzofuro[3,2-b][1] benzopyran-2-methoxy,3-hydroxy,5a,10a-dihydro) named (3 R *,2 R *)-3- O -2′-7-hydroxy-6-methoxyflavan. The structures of the new compounds were determined using spectroscopic methods.