Chemical investigation of L. fischeri afforded two new eremophilenolides. which were identified as 6 beta-methoxy-8 beta-hpdroxy-eremophil-7(11)-en-12,8 alpha-olide 1; 6-oxo-8 beta-hydroxy-eremophil-7(11)-en- 12.8 alp...Chemical investigation of L. fischeri afforded two new eremophilenolides. which were identified as 6 beta-methoxy-8 beta-hpdroxy-eremophil-7(11)-en-12,8 alpha-olide 1; 6-oxo-8 beta-hydroxy-eremophil-7(11)-en- 12.8 alpha-olide 2.展开更多
A novel eremophilane dimer,named fischelactone(1),was isolated from the roots of Ligularia fischeri.Complete structural elucidation of this compound was performed by HRESIMS,IR,1D NMR and 2D NMR(;H-;H COSY,HMBC,HMQ...A novel eremophilane dimer,named fischelactone(1),was isolated from the roots of Ligularia fischeri.Complete structural elucidation of this compound was performed by HRESIMS,IR,1D NMR and 2D NMR(;H-;H COSY,HMBC,HMQC and NOESY) data.展开更多
文摘为获得酶学性质优良的α-半乳糖苷酶,研究根据Gen Bank数据库提供的嗜热微生物Neosartorya fischeri的α-半乳糖苷酶的氨基酸序列,经密码子优化合成该酶的编码基因。将合成的基因转化大肠杆菌BL21进行原核表达,获得重组α-半乳糖苷酶,并对酶学性质进行研究。结果显示:以棉籽糖为底物时,酶的最适反应温度为55℃,最适p H 6.0,有较好的热稳定性和酸碱稳定性。Fe2+(铁)、Mn2+(锰)和Ca2+(钙)离子可使酶活性大幅提高,而Cu2+(铜)离子则可强烈抑制酶的活性,Pb2+(铅)、Ba2+(钡)、Al3+(铝)、EDTA(乙二胺四乙酸)和SDS(十二烷基硫酸钠)对酶活也有一定的抑制作用。在模拟胃肠环境时发现该酶有良好的稳定性,肠液对该酶甚至有轻微的激活作用。
文摘Chemical investigation of L. fischeri afforded two new eremophilenolides. which were identified as 6 beta-methoxy-8 beta-hpdroxy-eremophil-7(11)-en-12,8 alpha-olide 1; 6-oxo-8 beta-hydroxy-eremophil-7(11)-en- 12.8 alpha-olide 2.
基金financially supported by State Key Laboratory of Applied Organic Chemistry,Lanzhou University, China and Natural Science Foundation of Shandong Province,China(No.Y2008D23).
文摘A novel eremophilane dimer,named fischelactone(1),was isolated from the roots of Ligularia fischeri.Complete structural elucidation of this compound was performed by HRESIMS,IR,1D NMR and 2D NMR(;H-;H COSY,HMBC,HMQC and NOESY) data.