New Phenylpropanoid-Substituted Flavan-3-ols from the Leaves of Castanopsis sclerophylla

In the course of a chemotaxonomical study of Chinese Castanopsis species, two previously unknown flavan-3-ols, named sclerophynins A and B, were isolated from the leaves of C. sclerophylla, together with five related known compounds. On the basis of spectroscopic analysis, the new compounds were characterized to be (4S,8R,9S)-4-(3,4-dihydroxyphenyl)-8-(3,4,5-trihydroxyphenyl)- 3,4,9,10-tetrahydro-5,9-dihydroxy-2H,8H-benzo[1,2-b:3,4-b']dipyran-2- one and (4S,7S,8R)-4,8-bis(3,4-dihydroxyphenyl)-3,4,6,7-tetrahydro-5-glucopyranosyloxy- 7-hydroxy-2H,8H-benzo[1,2-b:5,4-b']dipyran-2-one, respectively.
HETEROCYCLES, 83(10), pp.2321-2328; 2011