目的为推动雷美替胺药品质量标准的提高,制备了雷美替胺的2种杂质。方法将雷美替胺原料进行高温破坏,产生目标杂质,再通过制备色谱和萃取,分离纯化得到纯度较高的目标杂质。分别用MS、1H NMR、13 C NMR对杂质进行结构确证。结果结构确...目的为推动雷美替胺药品质量标准的提高,制备了雷美替胺的2种杂质。方法将雷美替胺原料进行高温破坏,产生目标杂质,再通过制备色谱和萃取,分离纯化得到纯度较高的目标杂质。分别用MS、1H NMR、13 C NMR对杂质进行结构确证。结果结构确证结果表明,分离纯化得到的2种杂质与(S)-N-[2-(6-氧代-1,6,7,8-四氢-2H-茚并[5,4-b]呋喃-8-基)-乙基]-丙酰胺(杂质Ⅰ)、(S)-N-[2-(7,8-二氢-6H-茚并[5,4-b]呋喃-8-基)-乙基]-丙酰胺(杂质Ⅱ)的结构相符。结论分离纯化得到的2种杂质,具有较高的纯度,可以作为雷美替胺质量研究的对照物。展开更多
目的:制备盐酸多西环素中国药典2015年版(Ch P 2015)标准检测的紧邻主峰后杂质,并鉴定其结构。方法:以盐酸多西环素成盐用母液为对象,采用室温条件下半制备液相色谱分离纯化杂质;色谱条件:采用Synergi C_(18)(50 mm×250 mm,10μm)...目的:制备盐酸多西环素中国药典2015年版(Ch P 2015)标准检测的紧邻主峰后杂质,并鉴定其结构。方法:以盐酸多西环素成盐用母液为对象,采用室温条件下半制备液相色谱分离纯化杂质;色谱条件:采用Synergi C_(18)(50 mm×250 mm,10μm)色谱柱,以0.1%三氟乙酸水溶液(A)-0.1%三氟乙酸乙腈溶液(B)为流动相,线性梯度洗脱(A-B):0.0 min(85∶15)→40.0 min(60∶40)→40.5 min(85∶15)?50.0 min(85∶15),流速为80 m L·min^(-1);254 nm检测收集目标组分,旋转蒸发去除有机溶剂,冷冻干燥制得目标杂质;采用盐酸多西环素Ch P 2015标准中有关物质检查的高效液相色谱法确证制得物质为目标杂质并采用归一化方法测定其纯度;采用光谱综合分析等手段确证其结构。结果:制得目标杂质纯度为98.7%,结构确证为2-乙酰-2-脱氨甲酰多西环素(即EP 8.0中的盐酸多西环素杂质F),在有关物质测定用供试品溶液中添加该杂质后,多西环素后相邻峰面积显著增加。结论:盐酸多西环素Ch P 2015标准检测的紧邻主峰后杂质经制备色谱分离并成功鉴定,该结论被Ch P 2015采用。展开更多
A lithium-assisted approach has been developed for the exfoliation of pristine graphite, which allows the large-scale preparation of few-layer graphene nanosheets. The process involves an unexpected physical insertion...A lithium-assisted approach has been developed for the exfoliation of pristine graphite, which allows the large-scale preparation of few-layer graphene nanosheets. The process involves an unexpected physical insertion and exfoliafion, and the graphene nanosheets prepared by this method reveal undisturbed sp2-hybridized structures. A possible two-step mechanism, which involves the negative charge being trapped around the edges of the graphite layers and a subsequent lithiation process, is proposed to explain the insertion of lithium inside the graphite interlayers. If necessary, the present exfoliation can be repeated and thinner （single or 2-3 layer） graphene can be achieved on a large scale. This simple process provides an efficient process for the exfoliation of pristine graphite, which might promote the future applications of graphene.展开更多
文摘目的为推动雷美替胺药品质量标准的提高,制备了雷美替胺的2种杂质。方法将雷美替胺原料进行高温破坏,产生目标杂质,再通过制备色谱和萃取,分离纯化得到纯度较高的目标杂质。分别用MS、1H NMR、13 C NMR对杂质进行结构确证。结果结构确证结果表明,分离纯化得到的2种杂质与(S)-N-[2-(6-氧代-1,6,7,8-四氢-2H-茚并[5,4-b]呋喃-8-基)-乙基]-丙酰胺(杂质Ⅰ)、(S)-N-[2-(7,8-二氢-6H-茚并[5,4-b]呋喃-8-基)-乙基]-丙酰胺(杂质Ⅱ)的结构相符。结论分离纯化得到的2种杂质,具有较高的纯度,可以作为雷美替胺质量研究的对照物。
文摘目的:制备盐酸多西环素中国药典2015年版(Ch P 2015)标准检测的紧邻主峰后杂质,并鉴定其结构。方法:以盐酸多西环素成盐用母液为对象,采用室温条件下半制备液相色谱分离纯化杂质;色谱条件:采用Synergi C_(18)(50 mm×250 mm,10μm)色谱柱,以0.1%三氟乙酸水溶液(A)-0.1%三氟乙酸乙腈溶液(B)为流动相,线性梯度洗脱(A-B):0.0 min(85∶15)→40.0 min(60∶40)→40.5 min(85∶15)?50.0 min(85∶15),流速为80 m L·min^(-1);254 nm检测收集目标组分,旋转蒸发去除有机溶剂,冷冻干燥制得目标杂质;采用盐酸多西环素Ch P 2015标准中有关物质检查的高效液相色谱法确证制得物质为目标杂质并采用归一化方法测定其纯度;采用光谱综合分析等手段确证其结构。结果:制得目标杂质纯度为98.7%,结构确证为2-乙酰-2-脱氨甲酰多西环素(即EP 8.0中的盐酸多西环素杂质F),在有关物质测定用供试品溶液中添加该杂质后,多西环素后相邻峰面积显著增加。结论:盐酸多西环素Ch P 2015标准检测的紧邻主峰后杂质经制备色谱分离并成功鉴定,该结论被Ch P 2015采用。
基金This work was supported by the National Natural Science Foundation of China （No. 51222104） and the Fundamental Research Funds for the Central Universities.
文摘A lithium-assisted approach has been developed for the exfoliation of pristine graphite, which allows the large-scale preparation of few-layer graphene nanosheets. The process involves an unexpected physical insertion and exfoliafion, and the graphene nanosheets prepared by this method reveal undisturbed sp2-hybridized structures. A possible two-step mechanism, which involves the negative charge being trapped around the edges of the graphite layers and a subsequent lithiation process, is proposed to explain the insertion of lithium inside the graphite interlayers. If necessary, the present exfoliation can be repeated and thinner （single or 2-3 layer） graphene can be achieved on a large scale. This simple process provides an efficient process for the exfoliation of pristine graphite, which might promote the future applications of graphene.
