title: Synthesis and antityrosinase mechanism of benzaldehyde thiosemicarbazones: novel tyrosinase inhibitors.
abstract: p-Hydroxybenzaldehyde thiosemicarbazone (HBT) and p-methoxybenzaldehyde thiosemicarbazone (MBT) were synthesized and established by (1)H NMR and mass spectra. Both compounds were evaluated for their inhibition activities on mushroom tyrosinase and free-cell tyrosinase and melanoma production from B(16) mouse melanoma cells. Results showed that both compounds exhibited significant inhibitory effects on the enzyme activities. HBT and MBT decreased the steady state of the monophenolase activity sharply, and the IC(50) values were estimated as 0.76 and 7.0 μM, respectively. MBT lengthened the lag time, but HBT could not. HBT and MBT inhibited diphenolase activity dose-dependently, and their IC(50) values were estimated as 3.80 and 2.62 μM, respectively. Kinetic analyses showed that inhibition type by both compounds was reversible and their mechanisms were mixed-type. Their inhibition constants were also determined and compared. The research may supply the basis for the development of new food preservatives and cosmetic additives.
authors.affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005, China.
authors.forename: Liang-Hua
authors.initials: LH
authors.lastname: Chen
authors.forename: Yong-Hua
authors.initials: YH
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.forename: Kang-Kang
authors.initials: KK
authors.lastname: Song
authors.forename: Xuan
authors.initials: X
authors.lastname: Liu
authors.forename: Yu-Long
authors.initials: YL
authors.lastname: Jia
authors.forename: Jiang-Xing
authors.initials: JX
authors.lastname: Zhuang
authors.forename: Qing-Xi
authors.initials: QX
authors.lastname: Chen
mesh_terms: D000818:Animals; D001547:Benzaldehydes / Q000138:chemical synthesis* / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000494:pharmacology; D008543:Melanins / Q000096:biosynthesis; D008546:Melanoma, Experimental; D051379:Mice; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D012663:Semicarbazides / Q000737:chemistry; D013882:Thiosemicarbazones / Q000138:chemical synthesis* / Q000494:pharmacology*
chemical_list: D001547:Benzaldehydes; D004791:Enzyme Inhibitors; D008543:Melanins; D012663:Semicarbazides; D013882:Thiosemicarbazones; C005151:thiosemicarbazide; C024896:4-anisaldehyde; D014442:Monophenol Monooxygenase; C011483:4-hydroxybenzaldehyde