title: Inhibition of tyrosinase activity by polyphenol compounds from Flemingia philippinensis roots.
abstract: Flemingia philippinensis is used as a foodstuff or medicinal plant in the tropical regions of China. The methanol (95%) extract of the roots of this plant showed potent tyrosinase inhibition (80% inhibition at 30μg/ml). Activity-guided isolation yielded six polyphenols that inhibited both the monophenolase (IC50=1.01-18.4μM) and diphenolase (IC50=5.22-84.1μM) actions of tyrosinase. Compounds 1-6 emerged to be three new polyphenols and three known flavanones, flemichin D, lupinifolin and khonklonginol H. The new compounds (1-3) were identified as dihydrochalcones which we named fleminchalcones (A-C), respectively. The most potent inhibitor, dihydrochalcone (3) showed significant inhibitions against both the monophenolase (IC50=1.28μM) and diphenolase (IC50=5.22μM) activities of tyrosinase. Flavanone (4) possessing a resorcinol group also inhibited monophenolase (IC50=1.79μM) and diphenolase (IC50=7.48μM) significantly. In kinetic studies, all isolated compounds behaved as competitive inhibitors. Fleminchalcone A was found to have simple reversible slow-binding inhibition against monophenolase.
authors.affiliation: Division of Applied Life Science (BK21 plus program), IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Graduate Program in Biochemistry and Biophysics, Brandeis University, 415 South Street, Waltham, MA 02453, USA.
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Curtis-Long
authors.affiliation: Department of Functional Crop, National Institute of Crop Science, RDA, Miryang 627-803, Republic of Korea.
authors.forename: Byong Won
authors.initials: BW
authors.lastname: Lee
authors.affiliation: Division of Applied Life Science (BK21 plus program), IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Heung Joo
authors.initials: HJ
authors.lastname: Yuk
authors.affiliation: Division of Applied Life Science (BK21 plus program), IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Dae Wook
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Division of Applied Life Science (BK21 plus program), IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Xue Fei
authors.initials: XF
authors.lastname: Tan
authors.affiliation: Division of Applied Life Science (BK21 plus program), IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea. Electronic address: khpark@gnu.ac.kr.
authors.forename: Ki Hun
authors.initials: KH
authors.lastname: Park
mesh_terms: D001578:Benzopyrans / Q000302:isolation & purification / Q000494:pharmacology; D047188:Chalcones / Q000302:isolation & purification / Q000494:pharmacology; D002681:China; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D007887:Fabaceae / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D007700:Kinetics; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D010088:Oxidoreductases / Q000037:antagonists & inhibitors; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D059808:Polyphenols / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013729:Terpenes / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D001578:Benzopyrans; D047188:Chalcones; D004791:Enzyme Inhibitors; D047309:Flavones; D005419:Flavonoids; D059808:Polyphenols; D013729:Terpenes; C000592631:fleminchalcone C; C448459:lupinifolin; C070777:flemichin D; D010088:Oxidoreductases; C412191:monophenolase; D014442:Monophenol Monooxygenase
keywords: Dihydrochalcone; Fleminchalcone; Flemingia philippinensis; Tyrosinase