Study On The Synthesis And Bioactivity Of Thiosemicarbazones

Tyrosinase (EC. 1. 14. 18. 1), a copper-containing redoxidase enzyme, is widely distributed in microorganisms, animals, plants and hunman beings. It is responsible for transforming of L-tyrosine to DOPAquinine, which can produce melanin in a series steps. The abnormal formation of melanin may bring out serious diseases in human beings and browning in fruits and vegetables, so, it's of great interest to inhibit the activity of tyrosinase.In this study, seven compounds containing sulfur were designed and synthesized. The inhibitory effects and mechanism of these synthetical compounds had been elucidated. Then, some tyrosinase inhibitors were screened out through studying their inhibitory capacities on prepared cell-free tyrosinase from B16 melanoma cell line. the B16 cell viability, tyrosinase activity, melanin content and mRNA levels of tyrosinase, TRP-1, TRP-2 were assayed in presence of different concentrations of thiosemicarbazones. The contents and results listed as follows:Choose ethanol and water as solvent, acetic acid as catalyst, 7 thiosemicarzones compounds were successfully synthesized, and their chemical structures were elucidated by ESI-MS and NMR.The inhibitory mechanisms of the all 7 synthetical compounds on mushroom tyrosinase diphenolase were studied, and results showed that all of them were potential tyrosinase inhibitors. Furthermore, the inhibitory mechanism of these compounds was studied. And corresponding inhibition constants were mearsured.The inhibitory effect of all 7 synthetical compounds on mushroom tyrosinase monophenolase were studied, results showed that all of them except 3,4-dihydroxy-benzaldehydesemithiocarzone can decrease the tyrosinase monophenylase activity.The inhibitory effect of semithiocarboznes on prepared cell-free tyrosinase from B16 melanoma cell line. and from Carbage Butterfly were investigated, results showed that these compounds can inhibit the tyrosinase activity in different extent.In the end, the inhibition of melaningenesis by compound A₃ and A₇ were investigated, which provide a foundation of these compounds' usage as skin-whitening agents.