title: A new epicatechin gallate and calpain inhibitory activity from Orostachys japonicus.
abstract: Calpains are calcium-dependent proteases that cleave a variety of intracellular substrates. The overactivation of mu-calpain is associated with a wide range of disease conditions. To search for calpain inhibitors from natural products, the phytochemical constituents of the ethyl acetate fraction of the whole plant of Orostachys japonicus (Crassulaceae) were studied. The various chromatographic separation of this fraction led to the isolation of a new tannin, (-)-epicatechin 5-gallate (1) along with 9 known compounds. Their structures were elucidated by spectroscopic and chemical analyses. Among them, (-)-epicatechin 5-gallate (1) and kaempferol (9) exhibited moderate inhibitory activity against mu-calpain with IC(50) values of 18.0+/-2.9 and 15.4+/-2.0 microg/ml, respectively.
authors.affiliation: Bioanalysis and Biotransformation Research Center, Life Sciences Research Division, Korea Institute of Science & Technology, PO Box 131, Cheongryang, Seoul 130-650, Republic of Korea.
authors.forename: Hyoung Ja
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Kim
authors.forename: Da-Ae
authors.initials: DA
authors.lastname: Park
authors.forename: Changbae
authors.initials: C
authors.lastname: Jin
authors.forename: Seon Pyo
authors.initials: SP
authors.lastname: Hong
authors.forename: Yong Sup
authors.initials: YS
authors.lastname: Lee
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002154:Calpain / Q000037:antagonists & inhibitors*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D029627:Crassulaceae / Q000737:chemistry; D004912:Erythrocytes; D006801:Humans; D015394:Molecular Structure; D010936:Plant Extracts / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D011480:Protease Inhibitors; C539601:epicatechin 5-gallate; D002392:Catechin; D002154:Calpain