Some synthetic efforts directed to the proposed structure of stereocalpin A are disclosed. The stereogenic centers in the aldol unit were installed using the method of Evans and the intermediates obtained through a re...Some synthetic efforts directed to the proposed structure of stereocalpin A are disclosed. The stereogenic centers in the aldol unit were installed using the method of Evans and the intermediates obtained through a reliable route helped to reveal that the spectroscopic data reported earlier in the literature for the same structures were either erroneous or irrelevant.展开更多
A range of qinghaosu （artemisinin） analogues were synthesized from modified dihydroqinghao acid/aldehyde using dark singlet oxygen to trigger off the key step of the trioxane formation. The newly accessed 1,2,4-trio...A range of qinghaosu （artemisinin） analogues were synthesized from modified dihydroqinghao acid/aldehyde using dark singlet oxygen to trigger off the key step of the trioxane formation. The newly accessed 1,2,4-trioxanes featured a side chain extended from the carbon corresponding to the lactone carbonyl group of qinghaosu through a stable carbon-carbon single bond instead of an acetal oxygen-carbon bond in most similar analogues in the literature Biotin and various amines were also connected to the qinghaosu core, respectively, through such a linear tether in efforts to develop hybrids and potentially useful probes in search of the in vivo targets.展开更多
In continuation/checking of a previous synthesis directed toward the literature structure of stereocalpin A it was found that the data for a substantial part of the intermediates reported before were incorrect. Some o...In continuation/checking of a previous synthesis directed toward the literature structure of stereocalpin A it was found that the data for a substantial part of the intermediates reported before were incorrect. Some of the transfor- mations were not successfully reproduced and the failures were shown to be consequences of the presence of the N-Me and the particular location of the ester linkage. The origins of the ＂extra/minor＂ signals in the NMR for most of the intermediates, which tend to be mistaken as signs for the presence of impurity/isomers, are also discussed.展开更多
目的:建立恩格列净片有关物质测定的HPLC法。方法:采用辛烷基硅烷键合硅胶为填充剂的色谱柱(ZORBAX Rx-C8,250 mm×4.6 mm,5μm),以p H 3.5的磷酸水溶液为流动相A,甲醇-乙腈(1∶1)为流动相B,梯度洗脱,流速1.0 m L·min^(-1),检...目的:建立恩格列净片有关物质测定的HPLC法。方法:采用辛烷基硅烷键合硅胶为填充剂的色谱柱(ZORBAX Rx-C8,250 mm×4.6 mm,5μm),以p H 3.5的磷酸水溶液为流动相A,甲醇-乙腈(1∶1)为流动相B,梯度洗脱,流速1.0 m L·min^(-1),检测波长224 nm,柱温为25℃,进样量20μL,对有关物质进行定性、定量分析。结果:在选定的色谱条件下,恩格列净与相邻杂质及各杂质之间的分离度均大于1.5;杂质IMPD(恩格列净还原产物)、杂质IMPC(恩格列净开环产物)、杂质EMGA(恩格列净中间体)、杂质IMPF(恩格列净缩合产物)、杂质IMPG(恩格列净脱葡萄糖醇产物)的定量限分别为28.30、53.07、73.60、65.00和395.57 ng,且在各自的线性范围内线性关系良好(r>0.999,n=5),平均回收率(n=9)分别为100.7%、102.9%、97.4%、102.1%和102.9%。对3批恩格列净片进行有关物质测定,结果总杂质量在0.05%～0.06%范围内。结论:经方法学验证,本法简便、灵敏,专属性好,可用于恩格列净片有关物质的测定。展开更多
基金Project supported by the National Basic Research Program of China （9i3 Program） （No. 2010CB833200）, the National Natural Science Foundation of China （Nos. 21032002, 20921091, 20672129, 20621062, 20772143） and the Chinese Academy of Sciences （＂Knowledge Innovation＂, No. KJCX2.YW.H08）.
文摘Some synthetic efforts directed to the proposed structure of stereocalpin A are disclosed. The stereogenic centers in the aldol unit were installed using the method of Evans and the intermediates obtained through a reliable route helped to reveal that the spectroscopic data reported earlier in the literature for the same structures were either erroneous or irrelevant.
基金This work was supported by the National Natural Science Foundation of China （21532002, 21672244, 21372248） and Chinese Academy of Sciences.
文摘A range of qinghaosu （artemisinin） analogues were synthesized from modified dihydroqinghao acid/aldehyde using dark singlet oxygen to trigger off the key step of the trioxane formation. The newly accessed 1,2,4-trioxanes featured a side chain extended from the carbon corresponding to the lactone carbonyl group of qinghaosu through a stable carbon-carbon single bond instead of an acetal oxygen-carbon bond in most similar analogues in the literature Biotin and various amines were also connected to the qinghaosu core, respectively, through such a linear tether in efforts to develop hybrids and potentially useful probes in search of the in vivo targets.
文摘In continuation/checking of a previous synthesis directed toward the literature structure of stereocalpin A it was found that the data for a substantial part of the intermediates reported before were incorrect. Some of the transfor- mations were not successfully reproduced and the failures were shown to be consequences of the presence of the N-Me and the particular location of the ester linkage. The origins of the ＂extra/minor＂ signals in the NMR for most of the intermediates, which tend to be mistaken as signs for the presence of impurity/isomers, are also discussed.
文摘目的:建立恩格列净片有关物质测定的HPLC法。方法:采用辛烷基硅烷键合硅胶为填充剂的色谱柱(ZORBAX Rx-C8,250 mm×4.6 mm,5μm),以p H 3.5的磷酸水溶液为流动相A,甲醇-乙腈(1∶1)为流动相B,梯度洗脱,流速1.0 m L·min^(-1),检测波长224 nm,柱温为25℃,进样量20μL,对有关物质进行定性、定量分析。结果:在选定的色谱条件下,恩格列净与相邻杂质及各杂质之间的分离度均大于1.5;杂质IMPD(恩格列净还原产物)、杂质IMPC(恩格列净开环产物)、杂质EMGA(恩格列净中间体)、杂质IMPF(恩格列净缩合产物)、杂质IMPG(恩格列净脱葡萄糖醇产物)的定量限分别为28.30、53.07、73.60、65.00和395.57 ng,且在各自的线性范围内线性关系良好(r>0.999,n=5),平均回收率(n=9)分别为100.7%、102.9%、97.4%、102.1%和102.9%。对3批恩格列净片进行有关物质测定,结果总杂质量在0.05%～0.06%范围内。结论:经方法学验证,本法简便、灵敏,专属性好,可用于恩格列净片有关物质的测定。
