原人参二醇类皂苷(PPD)在酶反应中转化动态及其产物稀有皂苷的制备

目的为了生物转化低成本制备人参稀有皂苷,利用Aspergillus g.848菌的粗酶与市售的原人参二醇类皂苷(PPD)混合皂苷反应,制备人参稀有皂苷C-K、C-Mc、F_2单体和4种异构体的Rh2组皂苷。方法酶与PPD皂苷反应,生成稀有皂苷;用HPLC法测定PPD皂苷原料和产物皂苷的组成,用硅胶柱法分离产物中的单体皂苷,用NMR法确认产物单体皂苷结构;用UPLC-MS法确认产物Rh2组。结果原料PPD中含有人参皂苷Rb_1、Rd、Rb_2、Rc和4种异构体的人参皂苷Rg3组;酶反应时,若生产以F_2为主的皂苷时,最佳反应时间为1.5~2.0h;若生产以C-K为主的皂苷时,反应时间为24.0~30.0h;若生产以Rh2组为主的皂苷时,反应6.0~12.0h时,Rg_3组产量低而Rh_2组产量高。以C-K为主的皂苷生产中,从30 g的PPD皂苷酶反应得到20 g产物,经硅胶柱分离,得到8.16 g的C-K、1.01 g的C-Mc、0.45 g的F_2单体和0.19 g的Rh_2组皂苷,并以NMR和UPLC-MS法核对了其结构。结论 PPD皂苷经酶转化成功地制备了高活性C-K、C-Mc、F_2和Rh_2组皂苷。

Protopanaxadiol ginsenosides dynamics in enzymatic reaction and preparation of rare ginsenosides

Objective To cheaply prepare the rare ginsenosides by biotransformation, ginsenosides C-K, C-Mc, F₂, and Rh₂ from commercially available Protopanaxadiol (PPD) ginsenoside mixture were prepared using a crude enzyme of Aspergillus g.848 strain. Methods The rare ginsenosides were obtained from PPD ginsenosides by enzyme reaction; The composition of PPD raw materials and ginsenoside products was measured by HPLC. The monomer ginsenosides and Rh₂ group of enzyme reaction product were separated by a silica gel column; The produced monomer ginsenosides were identified by NMR; Rh₂ group was identified by UPLC-MS. Results The raw material of PPD ginsenosides was consisted of ginsenoside Rb₁, Rd, Rb₂, Rc, and Rg₃ groups with four kinds of isomers. During the reaction of enzyme, the best reaction time for the ginsenoside F₂ production was 1.5 h to 2 h; The best reaction time for the ginsenoside C-K production was 24 h to 30 h; If producing the Rh₂ group, when reacted to 6 h to 12 h, the content of Rg₃ group was low, and Rh₂ group was high. In the production of C-K, 20 g of crude products were obtained from 30 g of PPD ginsenosides by enzyme reaction, and 8.16 g of C-K, 1.01 g of C-MC, 0.45 g of F₂, and 0.19 g of Rh₂ group were separated using silica gel column. The rare ginsenosides were identified by NMR, and the Rh₂ group was identified using UPLC-MS method. Conclusion The high activity of monomer ginsenoside C-K, C-Mc, F₂, and Rh₂ group are successfully prepared from the PPD ginsenosides by enzymatic conversion.