Tyrosinase catalyzes two distinct sequential reactions in melanin biosynthesis: The hydroxylation of tyrosine to dihydroxyphenylalanine (DOPA) and the oxidation of DOPA to dopaquinone. Developing functional modulators of tyrosinase is important for therapeutic and cosmetic purposes. Given the abundance of thiourea moiety in known tyrosinase inhibitors, we studied other thiourea-containing drugs...

objective(s):involvement of tyrosinase in the synthesis of melanin and cell signaling pathway has made it an attractive target in the search for therapeutic inhibitors for treatment of different skin hyperpigmentation disorders and melanoma cancers. materials and methods: in the present study, we conducted a comprehensive kinetic analysis to understand the mechanisms of inhibition imposed by 2-...

The aim of this study was to investigate the effect of ethyl acetate fraction of Euryale ferox seed extracts (Efse-EA) on melanogenesis in immortalized mouse melanocyte cell line, melan-a. Efse-EA showed strong dose-dependent mushroom tyrosinase inhibitory activity. Treatment of melan-a cells with 30 μg/mL Efse-EA produced strong inhibition of cellular tyrosinase and melanin synthesis. Efse-EA ...

In this study, we repositioned thiopurine drugs used for the treatment of acute 12 leukaemia as new tyrosinase inhibitors. Tyrosinase catalyses two distinct and successive 13 oxidations in melanin biosynthesis: the conversions of tyrosine to dihydroxyphenylalanine (DOPA) 14 and DOPA to dopaquinone. Continuous efforts are underway to discover small molecule 15 inhibitors of tyrosinase for therap...

Ii(loleacetic acid is inactivated by mushroom tyrosinase or a tyrosinase present in dialyzed extracts of Osmunda leaves, but only when catechol or pyrogallol are also added. Tyrosine and DOPA do not promote IAA inactivation, although these phenols are oxidized by the enzvme. It appears probable that a reaction occurs between IAA and one of the intermediate compounds formed during the oxidation ...

In our efforts to find new whitening agent from natural resources, we focused on wood of Artocarpus heterophyllus which shows anti-melanogenesis activity. By activity-guided fractionation of A. heterophyllus wood extract, a new prenylated flavonoid, 3-prenyl luteolin (1) was isolated. The IC(50) of mushroom tyrosinase inhibitory activity of 1 was 76.3 microM. The results of the comparison with ...

Bioassay-guided investigation of the branches of Cleyera japonica led to the isolation of four phenolic constituents: 3,3’-di-O-methylellagic acid (1), 3,3’-di-O-methylellagic acid 4’-O-β-D-xylofuranoside (2), 3,5,7-trihydroxychromone 3-O-α-L-arabinofuranoside (3) and aviculin (4). Their structures were elucidated on the basis of spectral studies, as well as by comparison with literature data. ...