New flavanones from the leaves of Cryptocarya chinensis and their antituberculosis activity.

Four new flavanones, cryptoflavanones AD (14, resp.), together with eight known compounds, were isolated from the leaves of Cryptocarya chinensis. The structures of these new compounds were determined by spectral analyses. Among the isolated compounds, pinocembrin (5) and cryptocaryone (6) exhibited antituberculosis activity against Mycobacterium tuberculosis H37Rv strain in vitro with MIC values of 3.5 and 25.0 mu g/ml, respectively.