arbutin and thiosemicarbazide

A series of 4-functionalized phenyl-O-beta-D-glycosides were designed, synthesized and evaluated as a new class of mushroom tyrosinase inhibitors. The results demonstrated that compounds 6a-13a bearing a thiosemicarbazide moiety exhibited potent activities with IC50 values range from 0.31 to 52.8 microM. Particularly, compound 9a containing acetylated glucose moiety was found to be the most active molecule with an IC50 value of 0.31 microM. SARs analysis suggested that (1) the thiosemicarbazide moiety remarkably contributed to the increase of inhibitory effects on tyrosinase; (2) the configuration and bond type of sugar moiety also played a very important role in determining their inhibitory activities. The inhibition kinetics and inhibition mechanism study revealed that compound 9a was reversible and competitive type inhibitor, whereas compound 13a was reversible and competitive-uncompetitive mixed-II type inhibitor.

Topics: Agaricales; Drug Design; Glucosides; Glycosides; Kinetics; Monophenol Monooxygenase; Peptides; Semicarbazides; Structure-Activity Relationship

A series of 1-(1-arylethylidene)thiosemicarbazide compounds and their analogues were synthesized and characterized by 1H NMR, MS. Their tyrosinase inhibitory activities were investigated by an assay based on the catalyzing ability of tyrosinase for the oxidation of L-DOPA, comparing with 4-methoxycinnamic acid and arbutin. The results showed that (1) all the synthesized compounds could perform a significant inhibitory activity for tyrosinase; (2) for these compounds, the main active moiety interacting with the center of tyrosinase would be thiosemicarbazo group; (3) the inhibitory activity was close related with thiosemicarbazide moieties and the groups attached on the aromatic ring.

Topics: Binding Sites; Enzyme Activation; Molecular Structure; Peptides; Semicarbazides