Tannins and Related Compounds from Quisqualis indica

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)-HHDP-4,6-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 phenolcarboxylic acids: gallic acid (19), ellagic acid (20), flavogallonic acid (21), brevifolin carboxylic acid (22) and [IV] one other hydrolyzable tannin: punicalin (23).