title: Prolyl endopeptidase inhibitors from caryophylli flos.
abstract: Three prolyl endopeptidase inhibitors were isolated and identified as luteolin, quercetin and beta-sitosterol-3-O-beta-D-glucopyranoside with IC50 of 0.17, 0.19 and 27.5 ppm, respectively. The inhibition of two flavonoids were non-competitive with substrate. Twenty authentic flavonoids were tested in order to investigate structure-activity relationship. No significant relationship was found in them, however, catechol moiety of B-ring and 7-OH group in flavonoid skeleton were seemed to be responsible for the stronger activity.
authors.affiliation: Department of Agricultural Chemistry, College of Agriculture, Kyungpook National University, Taegu, Korea.
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
authors.forename: J H
authors.initials: JH
authors.lastname: Kwak
authors.forename: K B
authors.initials: KB
authors.lastname: Lee
authors.forename: K S
authors.initials: KS
authors.lastname: Song
mesh_terms: D006868:Hydrolysis; D007723:Korea; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010946:Plants, Medicinal / Q000737:chemistry*; D000085822:Prolyl Oligopeptidases; D011480:Protease Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D011480:Protease Inhibitors; D012697:Serine Endopeptidases; D000085822:Prolyl Oligopeptidases