Separation of the enantiomers of underivatized amino acids by using serially connected dual column high-performance liquid chromatography-tandem mass spectrometry.

In this article, a serially connected dual column liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is described for the simultaneous separation and enantioseparation of proteinogenic amino acids. For this purpose, different achiral and chiral stationary phases (CSP) and mobile phase compositions have been tested. As a result of the optimization studies, the best enatioseparation for amino acids were achieved with a combination of zwitterionic and crown ether stationary phases using a gradient of two mobile phases: A (water:TFA 99.5:0.5, % v/v) and B (acetonitrile:ethanol:TFA 85:15:0.5, % v/v/v). The developed method provided simultaneous enantioseparation of all proteinogenic amino acids under this study including isomeric and isobaric ones except for proline. The method was successfully applied to human lung adenocarcinoma cells (A549) and healthy human lung epithelial cells (BEAS-2B) cultivated with d-amino acid containing cocktails in order to evaluate d-amino acids transfer rate in normal and cancer lines. Thed/l amino acid ratios were different in cancer and normal cell lines cultivated as mentioned above for aspartic acid, cysteine, methionine, phenylalanine, and serine.

Paraoxonase 1 (PON1) promoter (-107T/C) and coding region (192Q/R and 55L/M) genetic variations in pseudoexfoliation syndrome and pseudoexfoliative glaucoma risk.

PURPOSE: Pseudoexfoliation syndrome (PEX) is characterized by the accumulation of microscopic extracellular material in the anterior chamber of the eye and can lead to the development of pseudoexfoliative glaucoma (PEG) in some patients. The pathogenesis of PEX is not fully understood, and there are no objective biomarkers for its early diagnosis. Recent research has indicated that oxidative stress and inflammation might play a role in the pathophysiology of the production of pseudoexfoliation material. Therefore, in the present study, we aimed to analyze the possible association between three genetic variants of paraoxonase 1 (PON1), a well-recognized antioxidant and anti-inflammatory enzyme, and PEX/PEG. METHODS: The study population consisted of patients with PEX (n = 150), patients with PEG (n = 150), and control subjects (n = 150). PON1 -107T/C, 192Q/R, and 55L/M genotypes were determined using PCR followed by restriction fragment length polymorphism analysis. The correlation between these genetic alterations and clinical visual characteristics was also investigated. RESULTS: The minor allele frequencies and genotype distributions of PON1 did not differ significantly between the PEG, PEX, and control groups. Moreover, PON1 genotypes did not significantly influence visual clinical parameters in stratification analysis. On the other hand, in correlation analysis, pattern standard deviation was significantly correlated with the -107T/C genotypes in PEX group. In addition, intraocular pressure was correlated with the 55L/M genotypes and mean deviation was correlated with the -107T/C genotypes in the control group. Furthermore, intraocular pressure was significantly inversely correlated with sex (r =  - 0.116, P = 0.011) in the overall study group. Logistic regression analysis showed that having a PON1 -107TC or CC genotype is significantly associated with PEX (OR = 1.909, P = 0.020). CONCLUSIONS: This study, for the first time, analyzed the relationship between PON1 genetic variants, clinical visual parameters, and PEX/PEG. The results indicated a possible role for the PON1 promoter variant in PEX.