title: Antityrosinase principles and constituents of the petals of Crocus sativus.
abstract: Three new monoterpenoids, crocusatin-J (1), -K (2), and -L (3), and a new naturally occurring acid, (3S),4-dihydroxybutyric acid (4), together with 31 known compounds were isolated and identified from the methanol extract of the petals of saffron (Crocus sativus). Their structures were established by spectroscopic methods. Among them, crocusatin-K (2), crocusatin-L (3), and 4-hydroxy-3,5,5-trimethylcyclohex-2-enone (8) showed significant antityrosinase activity, and protocatechuic acid (18), kaempferol (24), and kaempferol 7-O-beta-d-glucopyranoside (27) were more effective in scavenging alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radicals than alpha-tocopherol. In addition, the mechanism of tyrosinase inhibition by crocusatin-K (2) is also discussed.
authors.affiliation: Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan, Republic of China.
authors.forename: Chia-Ying
authors.initials: CY
authors.lastname: Li
authors.forename: E-Jian
authors.initials: EJ
authors.lastname: Lee
authors.forename: Tian-Shung
authors.initials: TS
authors.lastname: Wu
mesh_terms: D002681:China; D027622:Crocus / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D035264:Flowers / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006885:Hydroxybutyrates / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D044949:Kaempferols / Q000494:pharmacology; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D039821:Monoterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019906:Nuclear Magnetic Resonance, Biomolecular; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D006885:Hydroxybutyrates; D044949:Kaempferols; D039821:Monoterpenes; C484826:crocusatin J; C484827:crocusatin K; C484828:crocusatin L; C111420:4-hydroxybutyric acid; C006552:kaempferol; D014442:Monophenol Monooxygenase