Inhibitory kinetics of DABT and DABPT as novel tyrosinase inhibitors.

4-Dimethylaminobenzaldehyde-thiosemicarbazone (DABT) and 4-dimethylaminobenzaldehyde-N-phenyl-thiosemicarbazone (DABPT) were synthesized and established by (1)H and (13)C NMR and mass spectrum. Both compounds were evaluated for their inhibition activities on mushroom tyrosinase and their anti-tyrosinase kinetics was investigated. The results showed that both compounds exhibited significant inhibitory effects on activity of monophenolase and diphenolase; DABT and DABPT decreased the steady-state rate with 1.

Inhibitory effects of naphthols on the activity of mushroom tyrosinase.

Tyrosinase (EC 1.14.18.

Inhibition kinetics of chlorobenzaldehyde thiosemicarbazones on mushroom tyrosinase.

2-Chlorobenzaldehyde thiosemicarbazone (2-Cl-BT) and 4-chlorobenzaldehyde thiosemicarbazone (4-Cl-BT) were synthesized, and their inhibitory kinetics on the activity of mushroom tyrosinase were investigated. Results showed that these compounds exhibited significant inhibitory potency on both monophenolase activity and diphenolase activity of tyrosinase. For the monophenolase activity, both compounds could decrease the steady-state activity of the enzyme sharply, without any influence on the lag period.

Inhibitory effects of hinokitiol on tyrosinase activity and melanin biosynthesis and its antimicrobial activities.

The inhibitory effects of hinokitiol, a constituent of the woody oils isolated from Cupressaceae heartwood, on mushroom tyrosinase and melanin formation in B16 melanoma cells as well as its antimicrobial activity were investigated. Our results showed that hinokitiol could strongly inhibit both monophenolase activity and diphenolase activity of the enzyme and the inhibition was reversible. The IC(50) values were estimated as 9.

Inactivation kinetics of polyphenol oxidase from pupae of blowfly (Sarcophaga bullata) in the dimethyl sulfoxide solution.

The effects of dimethyl sulfoxide (DMSO) on the activity of polyphenol oxidase (PPO, EC 1.14.18.

Antityrosinase and antimicrobial activities of trans-cinnamaldehyde thiosemicarbazone.

Tyrosinase (EC 1.14.18.