Chiral α-Hydroxy Acid Discrimination in Tumor Tissues and Food Samples via Derivatization-Assisted MALDI-TIMS-MS

Effective differentiation of chiral metabolites, coupled with precise determination of their enantiomeric ratios, is crucial for advancing biomarker screening and gaining comprehensive insight into the etiology of metabolic disorders. Herein, we integrate a chiral derivatization strategy with matrix-assisted laser desorption/ionization (MALDI) coupled with trapped ion mobility spectrometry (TIMS) for chiral discrimination of α-hydroxy acids, 2-hydroxyglutarate (2-HG) and lactic acid (LA), in complex matrices. Systematic optimization of derivatization reagents N-(p-Toluenesulfonyl)-l-phenylalanyl chloride (TSPC) and diacetyl-l-tartaric anhydride (DATAN), with alkali metal ion adducts, enables high-resolution enantiomer separation of 2-HG and LA via diastereomeric conversion. This method exhibits an exceptional ability to determine enantiomeric ratios as low as 5.8%. The utility of this method is presented for sensitive identification of 2-HG in isocitrate dehydrogenase (IDH)-mutated tumor tissues and the precise determination of LA enantiomers in fermented foods, thus underscoring the significant potential for advancing research in food safety, pharmaceutical development, and clinical diagnostics.