Sensitive Bromine-Labeled Probe D‑BPBr for Simultaneous Identification and Quantification of Chiral Amino Acids and Amino-Containing Metabolites Profiling in Human Biofluid by HPLC/MS

• Published in: Analytical chemistry (Washington) 2020-01, Vol.92 (2), p.1763-1769
• Main Authors: Shen, Kexin, Wang, Lin, He, Quan, Jin, Zhe, Chen, Weiyi, Sun, Cuirong, Pan, Yuanjiang
• Format: Article
• Language: English
• Subjects: Amino acids; Amino Acids - analysis; Amino Acids - metabolism; Biomarkers; Biomarkers - analysis; Biomarkers - metabolism; Body Fluids - chemistry; Body Fluids - metabolism; Bromine; Bromine - chemistry; Bromine Radioisotopes; Chemistry; Chromatography, High Pressure Liquid; D-Amino acids; Enantiomers; Fluorescent Dyes - chemistry; High performance liquid chromatography; Humans; Isotopes; Labeling; Liquid chromatography; Mass Spectrometry; Metabolites; Selectivity; Separation; Spectrometry; Urine
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.9b03252

A novel bromine-isotope probe named D-BPBr with stereodynamic chiral recognition characteristics was developed for the labeling, separation, and detection of trace chiral amino acids and amino-containing metabolites. Fourteen enantiomeric pairs of amino acids could be successfully separated and quantified on a reverse-phase C18 column with an HPLC-MS/MS system after D-BPBr labeling. The chromatographic resolution for d,l-amino acid enantiomers ranged from 1.14 to 8.83 with the l-amino acid derivative always eluting prior to the corresponding d-enantiomer. Meanwhile, D-BPBr showed strong chiral selectivity on d-amino acids, and the ratio of mass spectrometric response for D-BPBr labeled d-amino acids to that of l-enantiomers ranged from 1.31 to 12.87 under the same condition. The D-BPBr labeling method was also demonstrated to be highly efficient and selective in separation and quantification of chiral amino acids especially for trace-level d-amino acids in human biofluids including urine and plasma, and in total, 11 l-amino acids and 10 d-amino acids in urine and 11 l-amino acids and 6 d-amino acids in plasma were detected and quantified. Based on the characteristic 2-Da mass difference of precursor ions and the nearly 1:1 peak intensity ratio originated from79Br and 81Br natural isotopes, as well as their dissociation features, 119 amino-containing metabolites were also rapidly detected in urine and plasma samples. Our work indicated that D-BPBr may be a potentially promising tool for the detection of d-amino acid-type biomarkers in disease diagnosis.