Camelliatannin D, a New Inhibitor of Bone Resorption, from Camellia japonica.

Camelliatannin D (1), a new complex tannin which inhibits Ca release from mouse calvaria, was isolated from the leaves and fruits of Camellia japonica L. (Theaceae). This tannin is the first example of complex tannin composed of a dimeric hydrolyzable tannin and a flavan-3-ol.