Morroniside consists of two anomeric isomers, α-morroniside and β-morroniside. These two anomeric compounds have been separated by reversed-phase high-performance liquid chromatography(HPLC) using a gradient mobile ...Morroniside consists of two anomeric isomers, α-morroniside and β-morroniside. These two anomeric compounds have been separated by reversed-phase high-performance liquid chromatography(HPLC) using a gradient mobile phase of acetonitrile-water at 7 ℃, and verified to be anomers of morroniside by ESI-TOF-MS. The higher peak in the chromatogram was appointed to α-morroniside according to NMR data reported in previous literature. The molar ratio of α-morroniside to β-morroniside was found to be 2.855∶1 at 25 ℃. Temperature appeared to be an important factor, which affects the separation result, and a better separation was achieved at a lower temperature. The relative peak height of β-morroniside in the total ion current chromatogram measured with positive ion ESI-TOF mass spectrometer was only a half of that in UV chromatogram. This indicates that β-morroniside is less sensitive to positive ion electrospray ionization than the α-isomer.展开更多
利用DNA重组技术在柞蚕蛹中表达重组人促红细胞生成素(Recombinant human erythropoietin,rhEPO),经过亲和层析纯化后,用SDS-PAGE分离纯化各组分,并通过电喷雾电离串联质谱技术(ESI-MS/MS)检测其糖基化修饰.结果显示,在柞蚕蛹中表达的rh...利用DNA重组技术在柞蚕蛹中表达重组人促红细胞生成素(Recombinant human erythropoietin,rhEPO),经过亲和层析纯化后,用SDS-PAGE分离纯化各组分,并通过电喷雾电离串联质谱技术(ESI-MS/MS)检测其糖基化修饰.结果显示,在柞蚕蛹中表达的rhEPO比活性约为1190 U/μg,其糖基化修饰位点与人体表达的EPO一致,有3个N-糖基化位点和1个O-糖基化位点.凝集素杂交实验结合质谱结果表明,柞蚕蛹表达的rhEPO的糖链中缺乏唾液酸修饰,而缺少唾液酸修饰的EPO通过鼻腔给药后在多种神经系统疾病的治疗中发挥着重要的作用.所得结果为进一步研究外源蛋白在柞蚕蛹-柞蚕核型多角体病毒(Anthraea pernyi nucleopolyhedrorirus,ApNPV)宿主载体表达系统表达后的糖基化与生物活性提供了依据.展开更多
文摘Morroniside consists of two anomeric isomers, α-morroniside and β-morroniside. These two anomeric compounds have been separated by reversed-phase high-performance liquid chromatography(HPLC) using a gradient mobile phase of acetonitrile-water at 7 ℃, and verified to be anomers of morroniside by ESI-TOF-MS. The higher peak in the chromatogram was appointed to α-morroniside according to NMR data reported in previous literature. The molar ratio of α-morroniside to β-morroniside was found to be 2.855∶1 at 25 ℃. Temperature appeared to be an important factor, which affects the separation result, and a better separation was achieved at a lower temperature. The relative peak height of β-morroniside in the total ion current chromatogram measured with positive ion ESI-TOF mass spectrometer was only a half of that in UV chromatogram. This indicates that β-morroniside is less sensitive to positive ion electrospray ionization than the α-isomer.
