应用C30-HPLC-DAD技术,建立一种同时分离全反式叶黄素、全反式β-隐黄质及其异构体的检测方法。采用APCI-MS和光谱技术对分离出化合物进行定性分析。最佳色谱条件：1.5%乙酸铵水-甲基叔丁基醚（MTBE）-甲醇（5：25：70,V/V/V）为流动相A...应用C30-HPLC-DAD技术,建立一种同时分离全反式叶黄素、全反式β-隐黄质及其异构体的检测方法。采用APCI-MS和光谱技术对分离出化合物进行定性分析。最佳色谱条件：1.5%乙酸铵水-甲基叔丁基醚（MTBE）-甲醇（5：25：70,V/V/V）为流动相A,1.5%乙酸铵水-甲基叔丁基醚（MTBE）-甲醇（5：85：10,V/V/V）为流动相B,线性梯度洗脱;流速：0.6 m L/min;洗脱时间：24min;进样量：20μL;柱温：25℃。混合物中的全反式叶黄素及其15-顺式、13/13’-顺式、9-顺式、9’-顺式异构体,全反式β-隐黄质及其15-顺式、13-和13’-顺式、9-顺式、9’-顺式异构体均得到较好分离。全反式叶黄素、全反式β-隐黄质分别在2~150 ng和5~250 ng范围内峰面积与进样量呈良好线性关系。该方法能够快速、准确地同时分离全反式叶黄素、全反式β-隐黄质及它们的异构体,可用于果蔬中全反式叶黄素和全反式β-隐黄质及其异构体混合物的定性定量分析。展开更多
为了建立分离度好、分离效率高的叶黄素顺、反异构体检测方法。通过对检测波长、流动相、流动相比例和流速等色谱条件的摸索和优化,确定最佳色谱条件,并采用光谱、高效液相色谱、质谱等方法对叶黄素顺、反异构体进行定性定量分析。结果...为了建立分离度好、分离效率高的叶黄素顺、反异构体检测方法。通过对检测波长、流动相、流动相比例和流速等色谱条件的摸索和优化,确定最佳色谱条件,并采用光谱、高效液相色谱、质谱等方法对叶黄素顺、反异构体进行定性定量分析。结果表明：该方法流动相为二氯甲烷-乙腈-甲醇（20∶30∶50,V/V）,流速为1.0 m L/min,叶黄素热异构化样品中各物质在12 min内达到有效分离,无拖尾现象,峰形较好;在叶黄素热异构化样品中鉴定出15-顺式、13/13′-顺式和9/9′-顺式叶黄素顺式异构体及全反式叶黄素,全反式叶黄素在4-260 ng范围内峰面积与进样量呈良好线形性关系,回收率在95%以上,精密度和稳定性相对标准偏差均小于2%。该方法分离度好、准确性高、重现性好。展开更多
A series of new dihydropyridines, butanamide, dihydropyridazines and thiourea derivatives have been prepared through the reactions of 3-aminopyridine （1） and N-（pyridin-3-yl）-3-（pyridin-3-ylimino）butanamide 3 wi...A series of new dihydropyridines, butanamide, dihydropyridazines and thiourea derivatives have been prepared through the reactions of 3-aminopyridine （1） and N-（pyridin-3-yl）-3-（pyridin-3-ylimino）butanamide 3 with some electrophilic reagents, aryl diazonium salts and isothiocyanates. Elementary analysis, MS, IR, and 1H NMR spectra confirmed the identity of the products.展开更多
Tocopherol sources in diets are often a combination of all-rac-a-tocopheryl acetate(synthetic a-tocopherol)from vitamin supplements and natural tocopherols and 2R-(4’R,8’R)-5,7,8-trimethyltocotrienol(a-tocotrienols)...Tocopherol sources in diets are often a combination of all-rac-a-tocopheryl acetate(synthetic a-tocopherol)from vitamin supplements and natural tocopherols and 2R-(4’R,8’R)-5,7,8-trimethyltocotrienol(a-tocotrienols)from the feed sources.Synthetic a-tocopherol consists of 8 different stereoisomers including 2R-(4’R,8’R)-5,7,8-trimethyltocol(RRR-a-tocopherol),2R-(4’S,8’R)-5,7,8-trimethyltocol(RSR-a-tocopherol),2R-(4’R,8’S)-5,7,8-trimethyltocol(RRS-a-tocopherol),2R-(4’S,8’S)-5,7,8-trimethyltocol(RSS-a-tocopherol),2S-(4’S,8’S)-5,7,8-trimethyltocol(SSS-a-tocopherol),2S-(4’R,8’S)-5,7,8-trimethyltocol(SRS-a-tocopherol),2S-(4’S,8’R)-5,7,8-trimethyltocol(SSR-a-tocopherol),and2S-(4’R,8’R)-5,7,8-trimethyltocol(SRR-a-tocopherol).The pre-absorption metabolism of tocopherols and tocotrienols in ruminants differs from monogastric animals due to the extensive microbial fermentation in the anaerobic rumen.The current study investigated the impact of toasting and decortication of oats on metabolism in the digestive tract(synthesis,digestion),and intestinal digestibility of tocopherols in dairy cows by using 4 ruminal and intestinal cannulated Danish Holstein cows in a 4×4 Latin square design for 4 periods.Cows were fed a total mixed ration ad libitum containing different forms of oats:whole oat,decorticated oat,toasted oat,and decorticated toasted oat,all rolled before mixed ration.Overall means across 4 treatments were statistically analyzed,testing whether overall means were different from zero.Decortication or toasting did not affect the balance or digestibility of a-tocopherols in rumen.Average across treatments showed the ruminal degradation of synthetic a-tocopherol(279 mg/d,P=0.02;P-value shows that average across treatments is different from zero),synthetic 2R-a-tocopherol(133 mg/d,P<0.01;summation of RRS-,RSR-and RSS-a-tocopherol),and 2S-a-tocopherol(190 mg/d;P<0.01,summation of SSS-,SRS-,SSR,and SRR-a-tocopherol),while RRR-a-tocopherol was formed in the rumen(221 mg/d,P=0.10).The aver展开更多
Bedaquiline is a new medicine for pulmonary multi-drug resistant tuberculosis （MDR-TB）, which is a pure enantiomer with two chiral centers. The current industrial preparation process requires the separation of activ...Bedaquiline is a new medicine for pulmonary multi-drug resistant tuberculosis （MDR-TB）, which is a pure enantiomer with two chiral centers. The current industrial preparation process requires the separation of active Bedaquiline from a mixture of four isomers. Obviously, direct dispose of the other three undesired stereoisomers will cause significant waste and increase the unnecessary cost of production. Here, we developed an efficient, facile and scalable process for recycling the inactive stereoisomers of Bedaquiline. All these inactive stereoisomers could be recycled by their conversion to two important intermediates in the Bedaquiline synthesis via a base-catalyzed Csp3-Csp3 bond cleavage of a benzyl alcohol intermediate. And the precise conditions and mechanism of the base-catalyzed cleavage reaction were discussed.展开更多
文摘应用C30-HPLC-DAD技术,建立一种同时分离全反式叶黄素、全反式β-隐黄质及其异构体的检测方法。采用APCI-MS和光谱技术对分离出化合物进行定性分析。最佳色谱条件：1.5%乙酸铵水-甲基叔丁基醚（MTBE）-甲醇（5：25：70,V/V/V）为流动相A,1.5%乙酸铵水-甲基叔丁基醚（MTBE）-甲醇（5：85：10,V/V/V）为流动相B,线性梯度洗脱;流速：0.6 m L/min;洗脱时间：24min;进样量：20μL;柱温：25℃。混合物中的全反式叶黄素及其15-顺式、13/13’-顺式、9-顺式、9’-顺式异构体,全反式β-隐黄质及其15-顺式、13-和13’-顺式、9-顺式、9’-顺式异构体均得到较好分离。全反式叶黄素、全反式β-隐黄质分别在2~150 ng和5~250 ng范围内峰面积与进样量呈良好线性关系。该方法能够快速、准确地同时分离全反式叶黄素、全反式β-隐黄质及它们的异构体,可用于果蔬中全反式叶黄素和全反式β-隐黄质及其异构体混合物的定性定量分析。
文摘为了建立分离度好、分离效率高的叶黄素顺、反异构体检测方法。通过对检测波长、流动相、流动相比例和流速等色谱条件的摸索和优化,确定最佳色谱条件,并采用光谱、高效液相色谱、质谱等方法对叶黄素顺、反异构体进行定性定量分析。结果表明：该方法流动相为二氯甲烷-乙腈-甲醇（20∶30∶50,V/V）,流速为1.0 m L/min,叶黄素热异构化样品中各物质在12 min内达到有效分离,无拖尾现象,峰形较好;在叶黄素热异构化样品中鉴定出15-顺式、13/13′-顺式和9/9′-顺式叶黄素顺式异构体及全反式叶黄素,全反式叶黄素在4-260 ng范围内峰面积与进样量呈良好线形性关系,回收率在95%以上,精密度和稳定性相对标准偏差均小于2%。该方法分离度好、准确性高、重现性好。
文摘A series of new dihydropyridines, butanamide, dihydropyridazines and thiourea derivatives have been prepared through the reactions of 3-aminopyridine （1） and N-（pyridin-3-yl）-3-（pyridin-3-ylimino）butanamide 3 with some electrophilic reagents, aryl diazonium salts and isothiocyanates. Elementary analysis, MS, IR, and 1H NMR spectra confirmed the identity of the products.
基金the Danish Milk Levy Fund (M■lkeafgiftsfonden, Aarhus, Denmark) for its financial support
文摘Tocopherol sources in diets are often a combination of all-rac-a-tocopheryl acetate(synthetic a-tocopherol)from vitamin supplements and natural tocopherols and 2R-(4’R,8’R)-5,7,8-trimethyltocotrienol(a-tocotrienols)from the feed sources.Synthetic a-tocopherol consists of 8 different stereoisomers including 2R-(4’R,8’R)-5,7,8-trimethyltocol(RRR-a-tocopherol),2R-(4’S,8’R)-5,7,8-trimethyltocol(RSR-a-tocopherol),2R-(4’R,8’S)-5,7,8-trimethyltocol(RRS-a-tocopherol),2R-(4’S,8’S)-5,7,8-trimethyltocol(RSS-a-tocopherol),2S-(4’S,8’S)-5,7,8-trimethyltocol(SSS-a-tocopherol),2S-(4’R,8’S)-5,7,8-trimethyltocol(SRS-a-tocopherol),2S-(4’S,8’R)-5,7,8-trimethyltocol(SSR-a-tocopherol),and2S-(4’R,8’R)-5,7,8-trimethyltocol(SRR-a-tocopherol).The pre-absorption metabolism of tocopherols and tocotrienols in ruminants differs from monogastric animals due to the extensive microbial fermentation in the anaerobic rumen.The current study investigated the impact of toasting and decortication of oats on metabolism in the digestive tract(synthesis,digestion),and intestinal digestibility of tocopherols in dairy cows by using 4 ruminal and intestinal cannulated Danish Holstein cows in a 4×4 Latin square design for 4 periods.Cows were fed a total mixed ration ad libitum containing different forms of oats:whole oat,decorticated oat,toasted oat,and decorticated toasted oat,all rolled before mixed ration.Overall means across 4 treatments were statistically analyzed,testing whether overall means were different from zero.Decortication or toasting did not affect the balance or digestibility of a-tocopherols in rumen.Average across treatments showed the ruminal degradation of synthetic a-tocopherol(279 mg/d,P=0.02;P-value shows that average across treatments is different from zero),synthetic 2R-a-tocopherol(133 mg/d,P<0.01;summation of RRS-,RSR-and RSS-a-tocopherol),and 2S-a-tocopherol(190 mg/d;P<0.01,summation of SSS-,SRS-,SSR,and SRR-a-tocopherol),while RRR-a-tocopherol was formed in the rumen(221 mg/d,P=0.10).The aver
基金financially supported by the National Science and Technology Major Project of China (No.521042)
文摘Bedaquiline is a new medicine for pulmonary multi-drug resistant tuberculosis （MDR-TB）, which is a pure enantiomer with two chiral centers. The current industrial preparation process requires the separation of active Bedaquiline from a mixture of four isomers. Obviously, direct dispose of the other three undesired stereoisomers will cause significant waste and increase the unnecessary cost of production. Here, we developed an efficient, facile and scalable process for recycling the inactive stereoisomers of Bedaquiline. All these inactive stereoisomers could be recycled by their conversion to two important intermediates in the Bedaquiline synthesis via a base-catalyzed Csp3-Csp3 bond cleavage of a benzyl alcohol intermediate. And the precise conditions and mechanism of the base-catalyzed cleavage reaction were discussed.
