Determination of Taurine in Infant Formula and Adult/Pediatric Nutritionals by Ultra High-Performance Liquid Chromatography with Multiple Reaction Monitoring-Mass Spectrometry: Single-Laboratory Validation, First Action 2022.08.

Background: Taurine (2-aminoethanesulfonic acid) is an essential β-amino acid, which is one of the most abundant intracellular amino acid component in humans. The level of free taurine in human milk is higher than in bovine milk. Since taurine is considered important for the development of a newborn, fortification of infant nutrition with taurine is common.

Rapid quantification of underivatized amino acids in plasma by hydrophilic interaction liquid chromatography (HILIC) coupled with tandem mass-spectrometry.

Background: Amino acidopathies are a class of inborn errors of metabolism (IEM) that can be diagnosed by analysis of amino acids (AA) in plasma. Current strategies for AA analysis include cation exchange HPLC with post-column ninhydrin derivatization, GC-MS, and LC-MS/MS-related methods. Major drawbacks of the current methods are time-consuming procedures, derivative problems, problems with retention, and MS-sensitivity.

D-serine influences synaptogenesis in a p19 cell model.

Recently, D-serine has been identified as an important NMDA-receptor co-agonist, which might play a role in central nervous system development. We investigated this by studying rat P19 cells, an established model for neuronal and glial differentiation. Our results show that (1) the D-serine synthesizing enzyme serine racemase was expressed upon differentiation, (2) extracellular D-serine concentrations increased upon differentiation, which was inhibited by serine racemase antagonism, and (3) inhibition of D-serine synthesis or prevention of D-serine binding to the NMDA-receptor increased synaptophysin expression and intercellular connections, supporting a role for NMDA-receptor activation by D-serine, synthesized by serine racemase, in shaping synaptogenesis and neuronal circuitry during central nervous system development.

Increased concentrations of both NMDA receptor co-agonists D-serine and glycine in global ischemia: a potential novel treatment target for perinatal asphyxia.

Worldwide, perinatal asphyxia is an important cause of morbidity and mortality among term-born children. Overactivation of the N-methyl-D-aspartate receptor (NMDAr) plays a central role in the pathogenesis of cerebral hypoxia-ischemia, but the role of both endogenous NMDAr co-agonists D-serine and glycine remains largely elusive. We investigated D-serine and glycine concentration changes in rat glioma cells, subjected to oxygen and glucose deprivation (OGD) and CSF from piglets exposed to hypoxia-ischemia by occlusion of both carotid arteries and hypoxia.

Two mass-spectrometric techniques for quantifying serine enantiomers and glycine in cerebrospinal fluid: potential confounders and age-dependent ranges.

Background: The recent discovery and specific functions of D-amino acids in humans are bound to lead to the revelation of D-amino acid abnormalities in human disorders. Therefore, high-throughput analysis techniques are warranted to determine D-amino acids in biological fluids in a routine laboratory setting.

Methods: We developed 2 chromatographic techniques, a nonchiral derivatization with chiral (chirasil-L-val column) separation in a GC-MS system and a chiral derivatization with Marfey's reagent and LC- MS analysis.