A study on the chemical constituents of the leaves of the Ilex pubescens Hook et Arn var glaber Chang. III. Elucidation of the structure of glaberide I. A new lignan compound - Qin, W J; Jiao, Z Y; Fan, Z T; Chen, B Q; Lin, X Y; Yao, J X (Yao Xue Xue Bao, 1980)