Ellagitannins and Related Compounds from Penthorum chinense

Four new ellagitannin metabolites, penthorumnins A–D (1–3 and 5), were isolated from the dried stem of Penthorum chinense. The structures were determined using spectroscopic and chemical analysis as well as using computations that revealed the following: (1) the acyl group of penthorumnin A (1) has a unique cyclopentane carboxylic acid structure that is derived from a hexahydroxydiphenoyl (HHDP) group; (2) penthorumnin B (2) has a...