Biotransformation of quercetin by Gliocladium deliquescens NRRL 1086  

作　　者：XU Jia-Qi FAN Ni YU Bo-Yang WANG Qian-Qian ZHANG Jian 

机构地区：[1]Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Research,China Pharmaceutical University,Nanjing 210009,China [2]Institute of Biotechnology for TCM Research,School of Traditional Chinese Medicine,China Pharmaceutical University,Nanjing 211198,China

出　　处：《Chinese Journal of Natural Medicines》2017年第8期615-624,共10页中国天然药物（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.21302052)

摘　　要：With an attempt to synthesize high-value isoquercitrin(quercetin-3-O-β-D-glucopyranoside), we carried out the biotransformation of quercetin(1) by Gliocladium deliquescens NRRL 1086. Along with the aimed product quercetin 3-O-β-D-glycoside(2), three additional metabolites, 2-protocatechuoyl-phlorogucinol carboxylic acid(3), 2,4,6-trihydroxybenzoic acid(4), and protocatechuic acid(5), were also isolated. The time-course experiments revealed that there were two metabolic routes, regio-selectivity glycosylation and quercetin 2,3-dioxygenation, co-existing in the culture. Both glycosylation and oxidative cleavage rapidly took place after quercetin feeding; about 98% quercetin were consumed within the initial 8 h and the oxdized product(2-protocatechuoyl-phlorogucinol carboxylic acid) was hydrolyzed into two phenolic compounds(2,4,6-trihydroxybenzoic acid and protocatechuic acid). We also investigated the impact of glucose content and metal ions on the two reactions and found that high concentrations of glucose significantly inhibited the oxidative cleavage and improved the yield of isoquercitrin and that Ca^(2+), Fe^(2+), Mn^(2+), Mg^(2+), and Zn^(2+) inhibited glycosylation. To test the promiscuity of this culture, we selected other four flavonols as substrates; the results demonstrated its high regio-selectivity glycosylation ability towards flavonols at C-3 hydroxyl. In conclusion, our findings indicated that the versatile microbe of G. deliquescens NRRL 1086 maitained abundant enzymes, deserving further research.With an attempt to synthesize high-value isoquercitrin （quercetin-3-O-fl-D-glucopyranoside）, we carried out the bio- transformation of quercetin （1） by Gliocladium deliquescens NRRL 1086. Along with the aimed product quercetin 3-O-β-D- glycoside （2）, three additional metabolites, 2-protocatechuoyl-phlorogucinol carboxylic acid （3）, 2,4,6-trihydroxybenzoic acid （4）, and protocatechuic acid （5）, were also isolated. The time-course experiments revealed that there were two metabolic routes, regio-selectivity glycosylation and quercetin 2,3-dioxygenation, co-existing in the culture. Both glycosylation and oxidative cleavage rapidly took place after quercetin feeding; about 98% quercetin were consumed within the initial 8 h and the oxdized product （2-protocatechuoyl-phlorogncinol carboxylic acid） was hydrolyzed into two phenolic compounds （2,4,6-trihydroxybenzoic acid and protocatechuic acid）. We also investigated the impact of glucose content and metal ions on the two reactions and found that high concentrations of glucose significantly inhibited the oxidative cleavage and improved the yield of isoquercitrin and that Ca2＋, Fe2＋, Mn2＋, Mg2＋, and Zn2＋ inhibited glycosylation. To test the promiscuity of this culture, we selected other four flavonols as substrates; the results demonstrated its high regio-selectivity glycosylation ability towards flavonols at C-3 hydroxyl. In conclusion, our findings indicated that the versatile microbe of G deliquescens NRRL 1086 maitained abundant enzymes, deserving further research.

关 键 词：Gliocladium deliquescens NRRL 1086 QUERCETIN BIOTRANSFORMATION GLYCOSYLATION Quercetin-2 3-dioxygenase 

分 类 号：R284[医药卫生—中药学]