Studies On The Inhibitory Effects And Inhibitory Mechanisms Of Inhibitors On The Activity Of Mushroom Tyrosinase

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.Screening the mushroom tyrosinase inhibitors and studying their inhibitory mechanism have been conducted.In view of the relationship between inhibition activity and structure of tyrosinase inhibitors,at the same time,inhibiton effects of tyrosinase by the compounds in cosmetics also have been studied.The contents and results are as follows:The effects of 4-hydroxybenzoic acid methyl ester,4-hydroxybenzoic acid ethyl ester,4-hydroxybenzoic acid propyl ester,4-hydroxybenzoic acid butyl ester,salicylic acid methyl ester,salicylic acid ethyl ester,3,5-dinitrosalicylic acid,6-sulfosalicylic acid,o-phenylene diamine and p-phenylene diamin on tyrosinase were studied,most of them can inhibit the activity of tyrosinase more or less,but 6-sulfosalicylic acid and o-phenylene diamine can activate the tyrosinase activity.The inhibition effects of phthalic acid,isophthalic acid and terephthalic acid on mushroom tyrosinase also have been investigated,results showed that phthalic acid had no inhibition effect on tyrosinase activity,isophthalic acid had a weaker inhition effect than terephthalic acid,the inhibition mechanism of terephthalic acid is reversible,and its inhibition type is mixed.The inhibition effects of 2-phenylacetaldehyde,2-phenylacetic acid, 2-phenylethanol,furfural,furoic acid,2-furylcarbinol,1,4-butyrolactone,maleic anhydride,1-naphthol,2-naphthol,rhodofix,n-octanoic acid,sorbic acid,n-hexylic acid,crotonic acid and ethyl acetic acid on mushroom tyrosinase have been determined,these compounds all have inhibition effects on tyrosinase activity,and the inhibition mechanism were reversible,the inhibition constants have been determined, the inhibition effects on monophenolase have been studied as well,results indicate that almost all of the compounds have inhibition effects on monophenolase except 2-phenylacetaldehyde.Synthesis of furan acrylic acid,2-chlorocinnamic acid,2,4-dichlorocinnamic acid,3,5-dimethoxycinnamic acid,and studying the inhition effects of these compounds on the activity of both monophenolase and diphenolase,all of them can inhibit the activity of both monophenolase and diphenolase,and the inhibition mechanisms are reversible,the inhibition type are noncompetitive.Synthesis of acetylsalicylic acidand acetyl-4-hydroxybenzoic acid,and studying the inhition effects of these compounds on the activity of diphenolase,them can inhibit the activity of tyrosinase,and the inhibition mechanisms are reversible,the inhibition type of acetyl-4-hydroxybenzoic acid is mixed type.The inhibition effects of some compounds in cosmetics have been researched, humectants:2-ethanediol,propanediol,glycerol,mannitol,sorbierite,inositol;fruit acids:glycolate,lactate,malate,tartrate,citrate,the compounds of humectants nearly have no inhibition effects on the activity of tyrosinase,but fruit acids glycolate has strong inhibition effect,the other fruit acids have weak inhibition effects,the inhibition mechanism of glycolate is reversible,and its inhibition type is mixed.The synthesis and inhibitory mechanism of new potential tyrosinase inhibitors were done in the study,which provided a foundation to develop high effective inhibitors and application in cosmetics.