Chunganenol: an unusual antioxidative resveratrol hexamer from Vitis chunganensis.

Chunganenol (1), an unusual resveratrol hexamer, has been isolated from Vitis chunganensis. Its unprecedented structure has been assigned through detailed analyses of 2D NMR data and consideration of oligostilbene biosynthetic pathway, representing the first highly condensed stilbene oligomer from Vitaceous plants. It also featured a novel interunit lingkage where two stilbene units are connected by a methylene bridge. Moreover, 1 exhibited potent and selective quenching effects on singlet oxygen, and might play a role in the antioxidative defense system of the plant.