Isolation of a novel catechin from Bergenia rhizomes that has pronounced lipase-inhibiting and antioxidative properties.

An aqueous ethanol extract of Bergenia crassifolia rhizomes strongly inhibited human pancreatic lipase activity and increased scavenging of DPPH free radicals in vitro. Chromatographic separation of this extract led to isolation of the hydrolysable tannins (+)-catechin 3,5-di-O-gallate (1) and (+)-catechin 3-O-gallate (2). This is the first report of the isolation of compound 1 from plant material. This compound strongly inhibited human pancreatic lipase (with an IC(50) value of 0.42 μg/ml) and exhibited a remarkable free radical-scavenging ability (with an SC(50) value of 1.04 μg/ml). The chemical structures of 1 and 2 were elucidated using MS, NMR and chemical approaches.