In this paper, some new results on the selective weak interaction between Na-4-tosyl-L-arginine methyl ester hydrochloride （TAME） and adenosine-5＇-triphosphate （ATP） have been reported. Fluorescence spectrophotom...In this paper, some new results on the selective weak interaction between Na-4-tosyl-L-arginine methyl ester hydrochloride （TAME） and adenosine-5＇-triphosphate （ATP） have been reported. Fluorescence spectrophotometry and Fourier transform infrared （FT-IR） spectroscopy were used to investigate this kind of weak interaction. In fluorescence experiments, obvious fluorescence quenching phenomena were observed when TAME was added, which indicated the weak interactions between TAME and ATP. It has been identified by fluorescence titration experiments that TAME exhibited high selectivity to ATP over ADP and AMP. FT-IR spectral results showed that an ATP-TAME adduct was formed. The experimental results indicated that the interaction sites were the guanidinium group of TAME main-chain and the γ-phosphate group of ATP, and the interaction took place through hydrogen bonding and electrostatic force. In addition, the effects of metal ions on the weak interaction between ATP and TAME, or between ATP and analogues of L-arginine were studied.展开更多
以L-半胱氨酸甲酯盐酸盐为起始原料,经4步反应合成了(R)-2-甲基半胱氨酸盐酸盐。在关键中间体(2R,4R)-2-叔丁基-3-甲酰基-4-甲基-1,3-噻唑烷-4-甲酸甲酯(4)的合成中,采用Self-regeneration of stereocenters原理,用六甲基二硅胺钠取代...以L-半胱氨酸甲酯盐酸盐为起始原料,经4步反应合成了(R)-2-甲基半胱氨酸盐酸盐。在关键中间体(2R,4R)-2-叔丁基-3-甲酰基-4-甲基-1,3-噻唑烷-4-甲酸甲酯(4)的合成中,采用Self-regeneration of stereocenters原理,用六甲基二硅胺钠取代文献方法中的二异丙基胺基锂,4的收率由文献的56%提高至90%。化合物的结构经1HNMR和MS表征。展开更多
Aim:To develop an HPCE method for the chiral separation of dopa methyl ester hydrochloride enantiomers.Methods:The enantiomers were separated by HPCE on a capillary of 63.5/72.0(I/L)cm×50 μm(i.d) with the backgr...Aim:To develop an HPCE method for the chiral separation of dopa methyl ester hydrochloride enantiomers.Methods:The enantiomers were separated by HPCE on a capillary of 63.5/72.0(I/L)cm×50 μm(i.d) with the background electrolyte of 20 mmol/L sodium dihydrogen phosphate,which containing 2.5% of highly sulfated-β-cyclodextrin as the chiral resolving additive adjusted to pH 2.55 with phosphoric acid.The outlet pressure injection mode and positive voltage of 30 kV electric force were used with the cassette temperature at 25 ℃ and UV detection at 210 nm.Attempts were made to optimized the separation conditions.Results:The enantiomers were baseline separated at the optimized conditions with the resolution greater than 2.The calibration curve was linear for L-dopa methyl ester hydrochloride in the range from 10 to 4 000 μg/mL using aminobenzoic acid as internal standard.And the limit of detection was 2.0 μg/mL.Conclusion:The established HPCE method is of high performance and economy for the chiral separation.It could be used as the routine method for the chiral purity analysis of L-dopa methyl ester hydrochloride.展开更多
基金Project supported by the National Natural Science Foundation of China （No. 90210027）.Acknowledgments The authors especially thank Zhide Hu in Lanzhou University for kindly allowing the use of the RF-5301PC spectrofluorophotometer （Shimadzu） in this work and Wenying He in Lanzhou University for active discussion as well as zealous help during the fluorescence experiments.
文摘In this paper, some new results on the selective weak interaction between Na-4-tosyl-L-arginine methyl ester hydrochloride （TAME） and adenosine-5＇-triphosphate （ATP） have been reported. Fluorescence spectrophotometry and Fourier transform infrared （FT-IR） spectroscopy were used to investigate this kind of weak interaction. In fluorescence experiments, obvious fluorescence quenching phenomena were observed when TAME was added, which indicated the weak interactions between TAME and ATP. It has been identified by fluorescence titration experiments that TAME exhibited high selectivity to ATP over ADP and AMP. FT-IR spectral results showed that an ATP-TAME adduct was formed. The experimental results indicated that the interaction sites were the guanidinium group of TAME main-chain and the γ-phosphate group of ATP, and the interaction took place through hydrogen bonding and electrostatic force. In addition, the effects of metal ions on the weak interaction between ATP and TAME, or between ATP and analogues of L-arginine were studied.
文摘以L-半胱氨酸甲酯盐酸盐为起始原料,经4步反应合成了(R)-2-甲基半胱氨酸盐酸盐。在关键中间体(2R,4R)-2-叔丁基-3-甲酰基-4-甲基-1,3-噻唑烷-4-甲酸甲酯(4)的合成中,采用Self-regeneration of stereocenters原理,用六甲基二硅胺钠取代文献方法中的二异丙基胺基锂,4的收率由文献的56%提高至90%。化合物的结构经1HNMR和MS表征。
文摘Aim:To develop an HPCE method for the chiral separation of dopa methyl ester hydrochloride enantiomers.Methods:The enantiomers were separated by HPCE on a capillary of 63.5/72.0(I/L)cm×50 μm(i.d) with the background electrolyte of 20 mmol/L sodium dihydrogen phosphate,which containing 2.5% of highly sulfated-β-cyclodextrin as the chiral resolving additive adjusted to pH 2.55 with phosphoric acid.The outlet pressure injection mode and positive voltage of 30 kV electric force were used with the cassette temperature at 25 ℃ and UV detection at 210 nm.Attempts were made to optimized the separation conditions.Results:The enantiomers were baseline separated at the optimized conditions with the resolution greater than 2.The calibration curve was linear for L-dopa methyl ester hydrochloride in the range from 10 to 4 000 μg/mL using aminobenzoic acid as internal standard.And the limit of detection was 2.0 μg/mL.Conclusion:The established HPCE method is of high performance and economy for the chiral separation.It could be used as the routine method for the chiral purity analysis of L-dopa methyl ester hydrochloride.
