title: Substituent effect of benzaldehydes on tyrosinase inhibition.
abstract: Benzaldehyde inhibited the oxidation of 4-t-butylcatechol catalyzed by mushroom tyrosinase with an IC50of 31.0 μM. The inhibition kinetics analyzed by Dixon plot indicated that it acts as a partial noncompetitive inhibitor. Further studies of several benzaldehydes, particularly those having a substitution at C-4, suggested that the partial inhibitory property diminished when using a bulk substituent. For example, 4-penthylbenzaldehyde showed a full and mixed type inhibition on diphenolase activity. Therefore, 4-substituted benzaldehyde on the aromatic ring primarily reflected the rate of product formation as it may act as a tight hydrophobic cover on the catalytic center of tyrosinase.
authors.affiliation: Department of Applied Biological Chemistry, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Tochigi 321-0943, Japan. Electronic address: nihei98@cc.utsunomiya-u.ac.jp.
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Nihei
authors.affiliation: Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3112, USA.
authors.forename: Isao
authors.initials: I
authors.lastname: Kubo
mesh_terms: D001547:Benzaldehydes / Q000737:chemistry / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects
chemical_list: D001547:Benzaldehydes; D004791:Enzyme Inhibitors; D014442:Monophenol Monooxygenase
keywords: Benzaldehydes; Dixon plot; Full inhibitor; Partial inhibitor; Tyrosinase