黄单胞菌生物催化合成α-熊果苷

Biocatalytic Synthesis of α-Arbutin by Xanthomonas BT-112

利用黄单胞菌(Xanthomonas)BT-112进行发酵,生物催化合成α-熊果苷.考察了反应温度、摇床转速和菌体对对苯二酚的最大耐受度、反应物浓度比、反应时间及糖的种类等因素对反应的影响.结果表明,用本方法合成的产物为单一的α-熊果苷.在温度35℃,摇床转速180 r/min,对苯二酚浓度48 mmol/L,蔗糖与对苯二酚的摩尔比2∶1,反应48 h的条件下,高达94.3%的对苯二酚转化为α-熊果苷.

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 ^13C NMR and ^1H NMR.