Gallotannins and related polyphenols from Pistacia weinmannifolia

Two new gallotannins, pistafolins A (1) and B (2), were isolated from the l eaf extract of Pistacia weinmannifolia. Their structures were determined by spectral methods. Four known gallotannins (3-6), seven known flavonoid gly cosides (7-13), along with 1-O-beta -D-(6'-O-galloyl)-glucopyranosyl-ethoxy -5-hydroxybenzene (14), gallic acid (15), methyl gallate (16), (+)-catechin (17), and (+)-gallocatechin (18), were also isolated. Some of these compou nds were tested for their cytotoxicity toward K562 cells, and two small mol ecular phenolic compounds, 15 and 18, showed significant inhibitory effects with IC50 Values less than 5 mug/ml.