Direct infusion mass spectrometry(DIMS) is a powerful technique in clinical diagnosis for screening neonatal amino acid metabolic disorders from dried blood spots(DBS).However,DIMS sometimes generated false-positive r...Direct infusion mass spectrometry(DIMS) is a powerful technique in clinical diagnosis for screening neonatal amino acid metabolic disorders from dried blood spots(DBS).However,DIMS sometimes generated false-positive results for analysis of amino acids.In this work,we utilized a stable isotope derivatization method,combining with liquid chromatography tandem mass spectrometry(SID-LC-MS),to improve the specificity for screening amino acids in DBS specimens.A pair of isotope reagents,p-(dimethylamino)phenyl isothiocyanate(DMAP-NCS) and 4-isothiocyanato-N,N-bis(methyl-[2H2])aniline([2H4]DMAP-NCS),was synthesized and used to label amino acids in DBS specimens.The [2H4]DMAP-NCS labelled amino acid standards were used as internal standards to compensate the matrix effect.This method was validated by measuring linearity,recovery and accuracy.The results showed that the developed SID-LC-MS method can be used for sensitive and selective determination of 12 diagnostically important amino acids in DBS specimens.展开更多
^(15)N isotope-labeled amino acids(^(15)N-amino acids)are crucial in the fields of biology,medicine,and chemistry.^(15)N-amino acids are conventionally synthesized through microbial fermentation and chemical reductive...^(15)N isotope-labeled amino acids(^(15)N-amino acids)are crucial in the fields of biology,medicine,and chemistry.^(15)N-amino acids are conventionally synthesized through microbial fermentation and chemical reductive amination of ketonic acids methodologies,which usually require complicated procedures,high temperatures,or toxic cyanide usage,causing energy and environmental concerns.Here,we report a sustainable pathway to synthesize ^(15)N-amino acids from readily available ^(15)N-nitrite(^(15)NO_(2)-)and biomass-derived ketonic acids under ambient conditions driven by renewable electricity.A mechanistic study demonstrates a ^(15)N-nitrite→^(15)NH_(2)OH→^(15)N-pyruvate oxime→^(15)N-alanine reaction pathway for ^(15)N-alanine synthesis.Moreover,this electrochemical strategy can synthesize six ^(15)N-amino acids with 68%–95%yields.Furthermore,a ^(15)N-labeled drug of ^(15)N-tiopronin,the most commonly used hepatitis treatment drug,is fabricated using ^(15)N-glycine as the building block.Impressively,^(15)N sources can be recycled by the electrooxidation of ^(15)NH4^(+) to ^(15)NO_(2)-with a method economy.This work opens an avenue for the green synthesis of ^(15)N-labeled compounds or drugs.展开更多
碳氮稳定同位素在地球科学、生命科学、环境科学、农业科学等各个领域有着广泛的应用。由于同时含有碳氮原子的氨基酸是蛋白质的构成单位,参与机体的代谢,具有重要的生物功能,因此在利用同位素示踪研究中,氨基酸有其重要的研究价值。本...碳氮稳定同位素在地球科学、生命科学、环境科学、农业科学等各个领域有着广泛的应用。由于同时含有碳氮原子的氨基酸是蛋白质的构成单位,参与机体的代谢,具有重要的生物功能,因此在利用同位素示踪研究中,氨基酸有其重要的研究价值。本文仅就利用气相色谱-燃烧-同位素比值质谱仪(gas chromatography-combustion-isotope ratio mass spectrometry,GC-C-IRMS)分析氨基酸的碳氮同位素比值的衍生化方法进行总结,比较各种方法的优缺点,以期对于分析氨基酸的碳氮同位素比值的研究工作提供有益的帮助。展开更多
基金supported by the National Key R&D Program of China(No.2018YFA0900400)the National Natural ScienceFoundation of China(Nos.21635006,31670373,21721005,21904099)the Postdoctoral Science Foundation of China(No.2018M642893)。
文摘Direct infusion mass spectrometry(DIMS) is a powerful technique in clinical diagnosis for screening neonatal amino acid metabolic disorders from dried blood spots(DBS).However,DIMS sometimes generated false-positive results for analysis of amino acids.In this work,we utilized a stable isotope derivatization method,combining with liquid chromatography tandem mass spectrometry(SID-LC-MS),to improve the specificity for screening amino acids in DBS specimens.A pair of isotope reagents,p-(dimethylamino)phenyl isothiocyanate(DMAP-NCS) and 4-isothiocyanato-N,N-bis(methyl-[2H2])aniline([2H4]DMAP-NCS),was synthesized and used to label amino acids in DBS specimens.The [2H4]DMAP-NCS labelled amino acid standards were used as internal standards to compensate the matrix effect.This method was validated by measuring linearity,recovery and accuracy.The results showed that the developed SID-LC-MS method can be used for sensitive and selective determination of 12 diagnostically important amino acids in DBS specimens.
基金supported by the National Natural Science Foundation of China(22271213)the National Postdoctoral Science Foundation of China(2022M722357)。
文摘^(15)N isotope-labeled amino acids(^(15)N-amino acids)are crucial in the fields of biology,medicine,and chemistry.^(15)N-amino acids are conventionally synthesized through microbial fermentation and chemical reductive amination of ketonic acids methodologies,which usually require complicated procedures,high temperatures,or toxic cyanide usage,causing energy and environmental concerns.Here,we report a sustainable pathway to synthesize ^(15)N-amino acids from readily available ^(15)N-nitrite(^(15)NO_(2)-)and biomass-derived ketonic acids under ambient conditions driven by renewable electricity.A mechanistic study demonstrates a ^(15)N-nitrite→^(15)NH_(2)OH→^(15)N-pyruvate oxime→^(15)N-alanine reaction pathway for ^(15)N-alanine synthesis.Moreover,this electrochemical strategy can synthesize six ^(15)N-amino acids with 68%–95%yields.Furthermore,a ^(15)N-labeled drug of ^(15)N-tiopronin,the most commonly used hepatitis treatment drug,is fabricated using ^(15)N-glycine as the building block.Impressively,^(15)N sources can be recycled by the electrooxidation of ^(15)NH4^(+) to ^(15)NO_(2)-with a method economy.This work opens an avenue for the green synthesis of ^(15)N-labeled compounds or drugs.
文摘碳氮稳定同位素在地球科学、生命科学、环境科学、农业科学等各个领域有着广泛的应用。由于同时含有碳氮原子的氨基酸是蛋白质的构成单位,参与机体的代谢,具有重要的生物功能,因此在利用同位素示踪研究中,氨基酸有其重要的研究价值。本文仅就利用气相色谱-燃烧-同位素比值质谱仪(gas chromatography-combustion-isotope ratio mass spectrometry,GC-C-IRMS)分析氨基酸的碳氮同位素比值的衍生化方法进行总结,比较各种方法的优缺点,以期对于分析氨基酸的碳氮同位素比值的研究工作提供有益的帮助。
