Study On The Biotransformation Of Motherwort From Hydroquinone To Arbutin

Arbutin possesses the effects of whitening,antibechic,anti-inflammatory,inhibition of insulin degradation and other beneficial effects.In recent years,the demand for arbutin in the cosmetics and pharmaceutical markets has been increasing year by year.This research chose Hydroponic Leonurus japonicus and cell suspension culture systems,to understand theHydroquinone biotransformation of arbutin.The results obtained from the experiments research are the following:1?The hydroponic Leonurus japonicus and cell suspension culture systems are both capable of biotransformation hydroquinone into arbutin;the product of the biotransformation using HPLC and mass spectrometry,is identified as?-arbutin.2?Arbutin extraction process has been optimized to:take fresh plant tissue and place under80?hot reflux for 1 h,methanol concentration was 70%,solid-liquid ratio 1:10.3?The optimal conditions for the Hydroponic Leonurus japonicus conversion of arbutin is:using water as the medium,5mmol/L hydroquinone,2.5mmol/L sucrose,24 h conversion time;suggested strategy of foliar spraying for once or hydroponic solution for multiple times in small amount of water;the highest transformation rate was 4.05%.4?The inducted of callus and early subcultured formula was MS+2,4-D _{0.5 mg/L}+6-BA _2mg/L;long term selected formula MS+2,4-D _{0.1 mg/L}+6-BA _{1 mg/L};the seedling hypocotyl was the best explants for callus induction;the process of subcultured obtained three colors:white,green,and purple callus;green callus has the best ability to generated arbutin;its best subcultured time or suspend time was about 13 d after inoculation;after built the Leonurus japonicus cell suspension culture systems,6⁸d after inoculation is suitable for subculture or transformation;the Leonurus japonicus cells has the characteristic of anti-hypoxia and fast-breeder,maximum biomass could reach 900 g/L.5?The best conditions of suspension cell produced of arbutin was 6 mmol/L hydroquinone,36 h converted,the biotransformation rate was the highest;the kinetic studies showed that prolonged conversion time,or increased concentration of hydroquinone led to cell lysised,and the intracellular arbutin all released into the extracellular;the highest biotransformation rate was30.59%.6?The above experimental results showed:The hydroponic Leonurus japonicus and cell suspension culture systems all have the ability to biotransform hydroquinone into arbutin.Using cell suspension culture system to transform,although conversion rate is high,but the aseptic operation cost and technology requirements are very high as well;therefore,the use of plants as a biotransformation system has the advantages of low cost,easy operation and easy popularization.The use of plants as the main body of transformation has enriched the existing biological transformation systems,which increases in theoretical value and applicable future.It is worth mentioning that foliar spray applied is better than the hydroponic solution?absorbed by root?,the biotransformation rate is greatly improved,convenient application,and can be used during field cultivation.It can also be used as a reference for the regulation of secondary metabolites in the cultivation of medicinal plants.