Small molecules NMR

UPASNA GUPTA (Centre of Biomedical Research, SGPGIMS Campus, Lucknow, India)

LinkedIn: Upasna Gupta, X: @Upasnagupta30

Abstract: Type 2 diabetes mellitus (T2DM) exacerbates the progression of chronic kidney disease (CKD) by intensifying metabolic and oxidative stress, however the underlying biochemical mechanisms remain incompletely understood in early stage CKD. This study aimed to delineate early metabolic alterations in CKD and to investigate diabetes-associated metabolic reprogramming using serum NMR-based metabolomics. A cohort of 100 early-stage CKD patients was analyzed using multivariate and univariate statistical approaches combined with pathway enrichment analysis. Distinct metabolic profiles clearly separated diabetic CKD from non-diabetic CKD. Notably, decreased levels of citrate, serine, and methionine indicated impaired tricarboxylic acid (TCA) cycle activity and disrupted one-carbon metabolism, consistent with a shift in systemic energy handling. Pathway analysis further confirmed significant perturbations in amino acid metabolism and central carbon metabolism, collectively suggesting diabetes-driven metabolic reprogramming in early CKD. These findings identify potential early biomarkers and provide mechanistic insight into diabetes-associated metabolic reprogramming, offering avenues for improved risk stratification and precision therapeutic strategies.

Denize Favaro (CUNY – Advanced Science Research Center, USA)

LinkedIn: @DenizeFavaro, X: @DenizeFavaro

Abstract: In 2018, a mechanism distinct from the formation of the inactive hydrolyzed β-lactam was described for 1-methyl-carbapenem hydrolysis by OXA-48, OXA-10, and OXA-23, leading to β-lactone formation. Previous studies have demonstrated that the S configuration at β-lactone C-2 can weakly inhibit these enzymes, and that the lactone-to-hydrolyzed product ratio can vary depending on the residues surrounding the active site. In this study, we used 1D-1H, 15N/1H-TROSY, and 1D-19F Nuclear Magnetic Resonance methods to demonstrate that OXA-143 can also hydrolyze the lactone product, resulting in lactone/hydrolyzed meropenem ratios that are highly dependent on the enzyme/antibiotic ratio, consistent with a reversible covalent inhibition mechanism.
Furthermore, using the cysteine variant OXA-143(D224C) labeled with 3-bromo-1,1,1-trifluoropropan-2-one (BTFA) and 19F-NMR, we identified the enzyme’s conformational states when bound to the substrate and the (S)- lactone, without the need for physical separation of the products. Additionally, the hMER binds weakly to the active site after the lactone is fully hydrolyzed.
Finally, the only mutant to show relevant differences in lactone-to-hydrolyzed product ratio was R261S – almost no lactone formation.

Pragati Gupta (Centre of Biomedical Research Institute Lucknow, India)

LinkedIn: Pragati Gupta, X: @praggupta856

Abstract: Gestational diabetes mellitus (GDM) is a major pregnancy-associated metabolic disorder characterized by glucose intolerance first recognized during pregnancy. Conventional diagnosis using oral glucose tolerance test (OGTT) is typically performed during the second trimester, limiting opportunities for early intervention . Our study aimed to investigate whether first-trimester serum metabolomics combined with clinical profiling could enable early predictive screening of GDM. In this prospective observational study, pregnant women recruited during the first trimester (7–13+6 weeks) were followed until routine OGTT screening at 24–28 weeks of gestation. Based on subsequent diagnosis, subjects were categorized into pre-GDM and non-GDM groups. Serum metabolic profiling was performed using high-field 800 MHz 1H NMR spectroscopy followed by multivariate statistical analysis including sparse Partial Least Squares Discriminant Analysis (sPLS-DA), receiver operating characteristic (ROC) analysis, and pathway interpretation. Distinct metabolic clustering between pre-GDM and non-GDM subjects was observed in the sPLS-DA model, indicating early metabolic perturbations preceding clinical GDM diagnosis. Several metabolites associated with glucose metabolism, branched-chain amino acid metabolism, energy metabolism, and gluconeogenesis exhibited significant alterations in pre-GDM subjects. Key discriminatory metabolites included glucose, alanine, valine, glutamine, histidine, and myo-inositol, with ROC analysis demonstrating strong diagnostic performance. Additionally, reduced alanine-to-glucose ratio suggested potential dysregulation of the hepatic alanine–glucose cycle and altered gluconeogenic metabolism during early pregnancy.
Overall, the study demonstrates that NMR-based clinico-metabolomics can identify early metabolic signatures predictive of GDM before conventional clinical diagnosis. These findings highlight the potential utility of metabolomics-assisted risk stratification as a non-invasive approach for early screening and timely intervention in high-risk pregnancies.