液相色谱法测定非天然氨基酸的光学纯度
以（1- 氟-2,4-二硝基苯基）-5-L-缬氨 酰胺为手性试剂、反相液相色谱法测定非天然氨基酸的光学 纯度。梯度洗脱，流动相A：含体积分数为0.1％的三氟乙酸的乙腈，流动相B：体积分 数为0.1％的三氟乙酸水溶液。L-和D-对映体得到良好分离。准确测定了25种非天然 氨基酸L-和D-对映体的光学纯度。
Determination of Chiral Purity of Synthetic Amino Acids by High Performance Liquid Chromatography after derivatization with （1- fluoro-2,4-dinitrophenyl）-5-L-valinamide （FDNP-Val-NH2）.The separation was performed with gradient elution.The phase A was acetonitrile containi ng 0.1% trifluoroacetic acid and phase B was 0.1% trifluoroacetic aci d.According to the hydrophobicity of the side chain of the amino acids,6 differe nt linear gradient programs were selected and all gradients completed in 20 minu tes.Good resolution was obtained for neutral amino acids.All L-L diastereomer o f neutral amino acids （the first letter refers to the configuration of amino aci d） were eluted faster than the D-L diastereomer with retention times less than 16 minutes.In the same gradient eluting system, the hydrophobic parameter （π value） and the position of the substituent in benzene ring of phenylalanine a lso influence the retention time of diastereomers.Usually the retention time of the phenylalanine with a large π value was longer than that with a small on e.Among the three phenylalanines containing the same |
