Inhibitory Mechanism Of Cashaw Nut Shell Liquid On Mushroom Tyrosinase And Its Biological Effects

Cashew nut shell liquid(CNSL)is an abundant natural resource,which is extracted from cashew nut shell.It has been widely used in traditional chemical polymer materials.In this research,the inhibitory mechanism,antioxidant activity and antibacterial activity of the main components of CNSL on mushroom tyrosinase were studied in order to promote their application in medicine and agriculture.The extraction technology of CNSL was optimized,and its related properties were analyzed.Two kinds of major phenolic compounds(cardol and cardanol)were isolated from CNSL by high performance liquid chromatography(HPLC),while identificating their purity to ensure the reliability.We studied the mushroom tyrosinase monophenolase and diphenolase enzyme inhibition of cardol and cardanol.We found that cardol/cardanol could not affect the abilities of mushroom tyrosinase monophenolase,but the enzyme tyrosinase diphenolase effectively.We studied the inhibitory mechnism of cardol/cardanol and mushroom tyrosinase,by kinetic analysis,the intrinsic/ANS-binding fluoresecence-quenching,isothermal trace calorimetry(ITC)and copper ion interactions experiments.The results showed that the enzyme has conformational changes,and cardol/cardanol interacted with the amino acid residues of the tyrosinase active site not the copper ions.Two cardol or one cardanol might enter to one tyrosinase,and interacted,that cardol had stronger interaction than cardanol.We found that the scavenging types of L-Ascorbic acid and cardol/cardanol are different in DPPH free radical scavenging experiment.Cardol/cardanol binded reversibly and tended to balance slowly.We further used Fusarium oxysporum,Colletotrichum camelliae,Fusarium moniliforme and Colletotrichum acutatum as the test to study antibacterial activities using the growth rate experiments.The results showed the inhibitory effects of cardol and cardanol were significant,and about ten times of CNSL.Collectively,we found CNSL and its components had remarkable inhibition on mushroom tyrosinase diphenolase and antibacterial effects.We should make more studies on their development and utilization values.