Tannins and Related Compounds from Quisqualis Indica

Abstract Continuous exploration of the chemical constituents of Combretaceous plants has led to the discovery of two novel ellagitannins, quisqualin A (1) and quisqualin B (2), from the fruits of Quisqualis indica. A total of twenty‐one other tannins were also isolated from either the fruits or leaves of Q. indica. including [I] eleven ellagitannins: 2,3‐(S)‐HHDP‐D‐glucose (3), 2,3‐(S)‐HHDP‐4‐O‐galloyl‐D‐glucose (4), 2,3‐(S)‐HHDP‐6‐O‐galloyl‐D‐glucose (5), 2,3‐(S)‐HHDPA6‐di‐O‐galloyl‐D‐glucose (6). pedunculagin (7), punicalagin (8), eugeniin (9), 1‐desgalloyleugeniin (10), casuariin (11), 5‐desgalloylstachyurin (12), castalagin (13); [II] five gallotannins‐. 6‐O‐galloyl‐D‐glucose (14), 1,6‐di‐O‐galloyl‐β‐D‐glucose (15), 2,3‐di‐O‐galloyl‐D‐glucose (16), 3,4‐di‐O‐galloyl‐D‐glucose (17), 4,6‐di‐O‐galloyl‐D‐glucose (18); [III] four phenol‐carboxylic acids: gallic acid (19), ellagic acid (20), flavogallonic acid (21), brevifolin carboxylic acid (22) and [IV] one other hydrolyzable tannin: punicalin (23).