化工学报2011，Vol.62Issue(11)：3136-3142,7.DOI:10.3969/i.issn.0438-1157.2011.11.023
水/离子液体[BMIM]PF6两相体系中全细胞催化生成单葡萄糖醛酸基甘草次酸
Biosynthesis of glycyrrhetic acid 3-O-mono-β-D-glucuronide by whole cell in ionic liquid/water biphasic system
摘要
Abstract
Glycyrrhizin (GL), the biologically active compounds of liquorice, can be hydrolysed to glycyrrhetic acid 3-O-mono-β-D-glucuronide (GAMG) by whole cells containing β-D-glucuronidase. GAMG is widely used in the pharmaceutical and food industries due to its stronger physiological functions, higher biological activity, more favorable sweetness, and lower caloric value as compared with GL. The recombinant Pichia pastoris (r-PGUS-P) designated in this work expressing β-D-glucuronidase, was used as a whole-cell biocatalyst catalyzing GL to GAMG in non-aqueous solvents systems. The results showed that r-PGUS-P gave the highest yield of GAMG in l-butyl-3-methylimidazolium hexafluorophosphate ( [BMIM] PF6 )/water (2 ∶ 8, vol) biphasic system. The optimal conditions of this reaction were determined as follows; optimum pH, substrate concentration, temperature and cell content were 5. 4, 6. 0 mmol · L-1, 45°C, and 8. 0 g · L-1, respectively. Under these optimized conditions, 69.6% yield of GAMG and 67. 2% of the chemical bond selectivity was achieved after 58 h reaction time, increase by 12. 4% and 12. 61%, respectively against aqueous phase. Simultaneously, the ionic liquid [BMIM]PF6 also remained at higher recovery percentage of about 93.47% during repeated use for 7 reaction cycles. Especially, product GAMG and byproduct glycyrrhetinic acid (GA) got separated in biphasic system automatically that brought convenience for the separation and purification of GAMG.关键词
离子液体/全细胞/甘草酸/β-D-葡萄糖醛酸苷酶/单葡萄糖醛酸基甘草次酸Key words
ionic liquid/whole-cell/glycyrrhizin/β-D-glucuronidase/glycyrrhetic acid 3-O-mono-β -D-glucuronide分类
生物科学引用本文复制引用
陈金燕,邹树平,何冬梅,杨晓刚,李春..水/离子液体[BMIM]PF6两相体系中全细胞催化生成单葡萄糖醛酸基甘草次酸[J].化工学报,2011,62(11):3136-3142,7.基金项目
国家自然科学基金项目(20976014) （20976014）
教育部博士点基金项目(20091101110036). （20091101110036）
