title: Tyrosinase inhibitory activities of the compounds isolated from Neolitsea aciculata (Blume) Koidz.
abstract: This study was designed to investigate the mushroom tyrosinase inhibitory activity for the constituents isolated from Neolitsea aciculata. The stems of N. aciculata was extracted with aqueous ethanol and subjected to chromatographic separation, which led to the isolation of 11 compounds: methyl linoleate (1), catechin (2), epicatechin (3), afzelin-7-O-glucopyranoside (4), 2',3'-di-(p-coumaroyl)afzelin (5), 2'-p-coumaroylafzelin (6), feruloyl tyramine (7), β-sitosterol (8), daucosterol (9), oleic acid (10), and trilaurin (11). Their structures were elucidated on the basis of spectroscopic studies as well as by comparison with the data available in the literature. Among these isolates, compounds 5 and 6 were identified as potent mushroom tyrosinase inhibitors with IC₅₀ values of 0.067 and 0.080 mM, respectively. The inhibition kinetics, analysed by Lineweaver-Burk plots, indicated that compounds 5 and 6 are competitive tyrosinase inhibitors when using l-tyrosine as a substrate. Notably, compounds 1-11 were isolated for the first time from this plant. These results provide evidence that this plant might be a potential source of anti-melanogenesis agents.
authors.affiliation: Department of Chemistry and Center for Cosmetic Sciences, Jeju National University, Jeju, Korea.
authors.forename: Sang Suk
authors.initials: SS
authors.lastname: Kim
authors.forename: Chang-Gu
authors.initials: CG
authors.lastname: Hyun
authors.forename: Young Hun
authors.initials: YH
authors.lastname: Choi
authors.forename: Nam Ho
authors.initials: NH
authors.lastname: Lee
mesh_terms: D000363:Agaricales / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D019770:Lauraceae / Q000737:chemistry*; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D014442:Monophenol Monooxygenase