利用电喷雾质谱研究单链寡聚核苷酸与人参皂苷的相互作用

Studies on the Interaction between Single-strand Oligonucleotide and Ginsenosides by Electrospray Ionization Mass Spectrometry

选择与SARS病毒相关的寡聚核苷酸片段作为靶分子,利用电喷雾质谱研究人参皂苷与靶分子形成的非共价复合物.探讨了实验条件对单链寡聚核苷酸靶分子与皂苷类化合物相互作用的影响;发现非共价作用强度的大小与人参皂苷苷元、糖链的结构有关,包括人参皂苷苷元的类型、羟基的数目、糖链的长短.发现人参皂苷与单链寡聚核苷酸靶分子相互作用的强度具有如下规律:三醇型苷元>二醇型苷元,三醇型皂苷>二醇型皂苷;在三醇型皂苷中,三糖>二糖>四糖,一糖>苷元,具有相同糖单位的二醇型皂苷的四糖苷中,分子量小的皂苷>分子量大的皂苷,同分异构体中,同为木糖末端的Rb2>Rc,即吡喃型>呋喃型.上述研究结果将有助于阐述人参皂苷的药理活性、构效关系.

Oligonucleotide from SARS virus was selected as a target molecule in the paper. The noncovalent complexes of ginsenosides with the target molecule were investigated by electrospray ionization mass spectrometry. The effects of experimental conditions were examined firstly on the formation of noncovalent complexes. Based on the optimized experimental conditions, the interaction of different ginsenosides with the target molecule was researched, finding that the interaction orders are relative with the structure of aglycons, the length and terminal sugar types of saccharide chains in the ginsenosides. There are certain rules for the interaction between the ginsenosides and DNA target molecule. For different type ginsenosides, the interaction intensity takes the orders 20-S-protopanaxatriol〉20-S-protopanaxadiol, and panaxatriol ginsenosides〉panaxadiol ginsenosides. For the ginsenosides with the same type aglycone, tri-saccharide chain〉 di-saccharide chain〉tetra-saccharide chain and single-saccharide chain〉panaxatriol. For the ginsenosides with the same tetra-saccharide chain, the ginsenosides with smaller molecule masses〉the ginsenosides with larger molecule masses. For some ginsenoside isomers with the same saccharide chain sequence, Rb2 with xylose（fur） terminal〉Rc with xylose（pyr） terminal, that is furanose form〉pyranose form. The above results are helpful for the elucidation of bio-activities and structure relationship of ginsenosides.