title: Prolyl endopeptidase inhibitors from green tea.
abstract: Three prolyl endopeptidase (PEP) inhibitors were isolated from the methanolic extract of green tea leaves. They were identified as (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (+)-gallocatechin gallate with the IC50 values of 1.42 x 10(-4) mM, 1.02 x 10(-2) mM, and 1.09 x 10(-4) mM, respectively. They were non-competitive with a substrate in Dixon plots and did not show any significant effects against other serine proteases such as elastase, trypsin, and chymotrypsin, suggesting that they were relatively specific inhibitors against PEP. The isolated compounds are expected to be useful for preventing and curing of Alzheimer's disease.
authors.affiliation: Dept. of Agricultural Chemistry, College of Agriculture, Kyungpook National University, Taegu, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
authors.forename: S I
authors.initials: SI
authors.lastname: Kim
authors.forename: K S
authors.initials: KS
authors.lastname: Song
mesh_terms: D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives / Q000302:isolation & purification / Q000494:pharmacology; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D000085822:Prolyl Oligopeptidases; D011480:Protease Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000378:metabolism*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010936:Plant Extracts; D011480:Protease Inhibitors; C417940:gallocatechin gallate; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate; D012697:Serine Endopeptidases; D000085822:Prolyl Oligopeptidases