N-新戊酰,O-异丙醇酯衍生法分析小麦氨基酸含量与碳氮稳定同位素

以2-氨基己二酸为内标,采用异丙醇和新戊酰氯将氨基酸衍生化成N-新戊酰基,O-异丙醇酯(NPP),利用气相色谱-质谱仪分析了小麦籽粒蛋白质氨基酸含量,同时利用气相色谱-燃烧-同位素比值质谱仪分析了氨基酸的碳氮稳定同位素组成。结果表明,N-新戊酰基,O-异丙醇酯(NPP)衍生化法可以得到丙氨酸、甘氨酸、缬氨酸、亮氨酸、异亮氨酸、脯氨酸、苯丙氨酸、赖氨酸和酪氨酸的较高的回收率(83.3%～104.9%)和较好的线性关系(相关系数为0.994～1.000);此方法还可以得到丙氨酸、甘氨酸、缬氨酸、亮氨酸、异亮氨酸、脯氨酸、天冬氨酸/天冬酰胺、苏氨酸、丝氨酸、蛋氨酸、谷氨酸/谷氨酰胺、苯丙氨酸、赖氨酸和酪氨酸的可靠的碳氮同位素比值。此方法可以为今后作物品质、营养和氨基酸代谢的深入研究提供更加有利的手段。

Analysis of Content and Stable Carbon and Nitrogen Isotope of Amino Acids by N-pivaloyl-isopropyl (NPP)Derivatives in Wheat Grain

The Content and stable carbon and nitrogen isotope composition of amino acids can be analyzed by gas chromatography-mass spectrograph and gas chromatography-combustion- isotope ratio mass spectrograph with 2-aminoadipic acid as internal standard based on N-pivaloyl-isopropyl （NPP） derivatives in wheat grain. Higher recoveries of amino acids were in the range of 83.3%-104.9% and good linear correlation coefficients were in the range of 0.994-1.000, including alanine, glycine, valine, leucine, isoleucine, proline, phenylalanine, lysine and tyrosine by this method. On the other hand, reliable stable carbon and nitrogen isotope composition of amino acids were obtained by this method, including alanine, glycine, valine, leucine, isoleucine, proline, aspartate/asparagine, threoine, serine, methionine, glutamic acid/glutamine, phenylalanine, lysine and tyrosine. The method provides a new way for developing the study of crop quality, nutrition, and amino acids metabolism.