Aim To investigate the structure of mogroside Ⅳa isolated from traditionalChinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] andsummarize the NMR characteristics of the structur...Aim To investigate the structure of mogroside Ⅳa isolated from traditionalChinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] andsummarize the NMR characteristics of the structure. Methods Common extraction, separation andpurification methods were used. Various NMR techniques including ~1H NMR, ^(13)C NMR, DEPT, ~1H-~1HCOSY, HSQC, HMBC, NOESY and molecular model simulated by computer were used to elucidate thestructure. Results ~1H and ^(13)C NMR signals of mogroside Ⅳa were assigned, and spectroscopicbasis was obtained for identification of such type of compounds. Conclusion 1D and 2D NMR techniquesincluding ~1H-~1H COSY, HSQC, HMBC, NOESY spectra are powerful tools for structure analysis. Thestructure determined by NMR methods is identical with energy minimized conformation simulated bycomputer.展开更多
为评价动植物源天然产物的二肽基肽酶-Ⅳ(dipeptidyl peptidase-Ⅳ,DPP-Ⅳ)抑制活性,以苦瓜皂苷(momordica saponins,MS)、乳清蛋白胃蛋白酶水解物(whey protein pepsin hydrolysates,WPPHs)、乳清蛋白胰蛋白酶水解物(whey protein tryp...为评价动植物源天然产物的二肽基肽酶-Ⅳ(dipeptidyl peptidase-Ⅳ,DPP-Ⅳ)抑制活性,以苦瓜皂苷(momordica saponins,MS)、乳清蛋白胃蛋白酶水解物(whey protein pepsin hydrolysates,WPPHs)、乳清蛋白胰蛋白酶水解物(whey protein trypsin hydrolysates,WPTHs)为原料,采用单因素试验和响应面分析优化水解条件,再将MS与WPPHs、WPTH进行复配,结合模拟体外消化,探究DPP-Ⅳ抑制活性。结果表明,MS、WPPHs及WPTHs具有DPP-Ⅳ抑制活性,最佳水解条件为:当酶添加量4%、pH2.7酶解2h时,WPPHs的DPP-Ⅳ抑制率最高为15.43%;当酶添加量4%、pH 7.6酶解4 h时,WPTHs的DPP-Ⅳ抑制率最高为14.62%。苦瓜皂苷与乳清蛋白水解物具有协同对二肽基肽酶-Ⅳ抑制活性作用,当MS与WPPHs、WPTHs的复配体积比均为1:1时,显著高于两者单独累加(p<0.05)。经胃消化后,WPPHs的DPP-Ⅳ抑制率降低2.02%,MS和WPTHs的DPP-Ⅳ抑制率升高0.99%、7.01%;经肠道消化后,WPPHs的DPP-Ⅳ抑制率升高2.23%,而MS和WPTHs的DPP-Ⅳ抑制率降低4.12%、2.70%。研究结果可为天然动植物源产物协同对二肽基肽酶-Ⅳ抑制活性提供了基础性数据,为降血糖功能性产品的开发提供新的方向。展开更多
文摘Aim To investigate the structure of mogroside Ⅳa isolated from traditionalChinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] andsummarize the NMR characteristics of the structure. Methods Common extraction, separation andpurification methods were used. Various NMR techniques including ~1H NMR, ^(13)C NMR, DEPT, ~1H-~1HCOSY, HSQC, HMBC, NOESY and molecular model simulated by computer were used to elucidate thestructure. Results ~1H and ^(13)C NMR signals of mogroside Ⅳa were assigned, and spectroscopicbasis was obtained for identification of such type of compounds. Conclusion 1D and 2D NMR techniquesincluding ~1H-~1H COSY, HSQC, HMBC, NOESY spectra are powerful tools for structure analysis. Thestructure determined by NMR methods is identical with energy minimized conformation simulated bycomputer.
