A new biflavonoid and an isobiflavonoid from Rhus tripartitum.

A new biflavonoid masazinoflavanone (1) and the isobiflavonoid calodenone (2) have been isolated and characterized from the methanolic aerial part extract of the plant Rhus tripartitum. Their structures have been deduced from extensive spectral analysis (NMR and MS). Interpretation of the nuclear overhauser effects (NOESY) permitted us to establish relative stereochemistry of these natural products.