Biocatalytic Synthesis of α-Arbutin by Xanthomonas BT-112

α-Arbutin has been recently found to be a useful cosmetic ingredient since it has a stronger inhibitory effect on tyrosinase than β-arbutin that is widely used in cosmetics.However,α-arbutin is not a natural product and difficult to be chemically synthesized.In this paper,a bacterium of Xanthomonas BT-112 was isolated and used for the anomer-selective synthesis of α-arbutin from hydroquinone and sucrose.The effects of reaction temperature,shaking speed,hydroquinone concentration,and reactant composition were investigated.When the suspension of Xanthomonas BT-112 was incubated at 35 ℃ with 48 mmol/L hydroquinone and 96 mmol/L sucrose,only one form of hydroquinone glucoside,α-arbutin,was obtained as a product.Under these conditions,the conversion based on the amount of hydroquinone supplied reached 94.3%.The product was identified by(()~(13)C) NMR and()~1H NMR.