Elucidating Chiral Resolution of Aromatic Amino Acids Using Glycopeptide Selectors: A Combined Molecular Docking and Chromatographic Study

\ua9 2024 by the authors.An asymmetric synthesis is a favorable approach for obtaining enantiomerically pure substances, but racemic resolution remains an efficient strategy. This study aims to elucidate the chiral resolution of aromatic amino acids and their elution order using glycopeptides as chiral selectors through molecular docking analysis. Chiral separation experiments were conducted using Vancomycin as a chiral additive in the mobile phase (CMPA) at various concentrations, coupled with an achiral amino column as the stationary phase. The Autodock Vina 1.1.2 software was employed to perform molecular docking simulations between each enantiomer (ligand) and Vancomycin (receptor) to evaluate binding affinities, demonstrate enantiomeric resolution feasibility, and elucidate chiral recognition mechanisms. Utilizing Vancomycin as CMPA at a concentration of 1.5 mM enabled the separation of tryptophan enantiomers with a resolution of 3.98 and tyrosine enantiomers with a resolution of 2.97. However, a poor chiral resolution was observed for phenylalanine and phenylglycine. Molecular docking analysis was employed to elucidate the lack of separation and elution order for tryptophan and tyrosine enantiomers. By calculating the binding energy, docking results were found to be in good agreement with experimental findings, providing insights into the underlying mechanisms governing chiral recognition in this system and the interaction sites. This comprehensive approach clarifies the complex relationship between chiral discrimination and molecular architecture, offering valuable information for creating and improving chiral separation protocols

Plasma levels of matrix metalloproteinase-2, -3, -10, and tissue inhibitor of metalloproteinase-1 are associated with vascular complications in patients with type 1 diabetes: The EURODIAB Prospective Complications Study

Impaired regulation of extracellular matrix remodeling by matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) may contribute to vascular complications in patients with type 1 diabetes. We investigated associations between plasma MMP-1, -2, -3, -9, -10 and TIMP-1, and cardiovascular disease (CVD) or microvascular complications in type 1 diabetic patients. We also evaluated to which extent these associations could be explained by low-grade inflammation (LGI) or endothelial dysfunction (ED). Methods: 493 type 1 diabetes patients (39.5 ± 9.9 years old, 51% men) from the EURODIAB Prospective Complications Study were included. Linear regression analysis was applied to investigate differences in plasma levels of MMP-1, -2, -3, -9, -10, and TIMP-1 between patients with and without CVD, albuminuria or retinopathy. All analyses were adjusted for age, sex, duration of diabetes, Hba1c and additionally for other cardiovascular risk factors including LGI and ED. Results: Patients with CVD (n = 118) showed significantly higher levels of TIMP-1 [β = 0.32 SD (95%CI: 0.12; 0.52)], but not of MMPs, than patients without CVD (n = 375). Higher plasma levels of MMP-2, MMP-3, MMP-10 and TIMP-1 were associated with higher levels of albuminuria (p-trends were 0.028, 0.004, 0.005 and 0.001, respectively). Severity of retinopathy was significantly associated with higher levels of MMP-2 (p-trend = 0.017). These associations remained significant after further adjustment for markers of LGI and ED. Conclusions: These data support the hypothesis that impaired regulation of matrix remodeling by actions of MMP-2, -3 and-10 and TIMP-1 contributes to the pathogenesis of vascular complications in type 1 diabetes

Relationship Between Risk Factors and Mortality in Type 1 Diabetic Patients in Europe: The EURODIAB Prospective Complications Study (PCS)

OBJECTIVE—The purpose of this study was to examine risk factors for mortality in patients with type 1 diabetes

Performance analysis of priority queueing systems in discrete time

The integration of different types of traffic in packet-based networks spawns the need for traffic differentiation. In this tutorial paper, we present some analytical techniques to tackle discrete-time queueing systems with priority scheduling. We investigate both preemptive (resume and repeat) and non-preemptive priority scheduling disciplines. Two classes of traffic are considered, high-priority and low-priority traffic, which both generate variable-length packets. A probability generating functions approach leads to performance measures such as moments of system contents and packet delays of both classes

Do European people with type 1 diabetes consume a high atherogenic diet? 7-year follow-up of the EURODIAB Prospective Complications Study

BACKGROUND/OBJECTIVES: Individuals with type 1 diabetes have a high risk of developing cardiovascular diseases, and it has been reported that they consume a high atherogenic diet. We examined how nutrient intake and adherence to current European nutritional recommendations evolved in a large cohort of European individuals with type 1 diabetes over a period of 7 years. SUBJECTS/METHODS: We analysed data from the EURODIAB Prospective Complications Study, a European multicentre prospective cohort study. Standardized 3-day dietary records were employed in individuals with type 1 diabetes. One thousand one hundred and two patients (553 men, 549 women, baseline age 33 ± 10 years, duration 15 ± 9 years) had complete nutritional data available at baseline and after 7 years. We calculated mean differences in reported nutrients over time and adjusted these for age, gender, HbA1c and BMI with ANOVA models. RESULTS: Compared to baseline, there were minor changes in nutrients. Reported protein (-0.35% energy (en), fat (-1.07% en), saturated fat (-0.25% en) and cholesterol (-7.42 mg/1000 kcal) intakes were lower, whereas carbohydrate (+1.23% en) and fibre (+0.46 g/1000 kcal) intakes were higher at the 7-year follow-up. European recommendations for adequate nutrient intakes were followed in individuals with type 1 diabetes for protein (76% at baseline and 78% at follow-up), moderately for fat (34, 40%), carbohydrate (34, 41%) and cholesterol (39, 47%), but poorly for fibre (1.4, 2.4%) and saturated fat (11, 13%). CONCLUSION: European individuals with type 1 diabetes consume a high atherogenic diet as few patients met recommendations for dietary fibre and saturated fat. This study showed minor changes in dietary nutrients and energy intakes over a period of 7 years. Nutrition education needs particular focus on strategies to increase dietary fibre and reduce saturated fat to exploit their potential benefi

Serum high-mobility group box-1 levels are positively associated with micro- and macroalbuminuria but not with cardiovascular disease in type 1 diabetes: the EURODIAB Prospective Complications Study.

CONTEXT AND OBJECTIVE: High-mobility group box-1 (HMGB1) is a pro-inflammatory cytokine that may contribute to the pathogenesis of micro- and macrovascular complications commonly observed in diabetes. We investigated whether HMGB1 is associated with: i) markers of low-grade inflammation (LGI) and endothelial dysfunction (ED) and pulse pressure (PP, a marker of arterial stiffness); ii) prevalent nephropathy, retinopathy and cardiovascular disease (CVD) in type 1 diabetes; and iii) the potential mediating roles of LGI, ED and PP therein. DESIGN AND METHODS: This was a cross-sectional nested case-control study of 463 patients (226 women; mean age 40±10 years) with type 1 diabetes from the EURODIAB Prospective Complications Study. We used linear and binary or multinomial logistic regression analyses adjusted for traditional risk factors. RESULTS: Serum Ln-HMGB1 levels were positively associated with LGI and ED (standardised β=0.07 (95% confidence interval (CI): 0.02-0.12) and β=0.08 (95% CI: 0.02-0.14) respectively), but not with PP. Higher Ln-HMGB1 (per unit) was associated with greater odds of micro- and macroalbuminuria: odds ratio (OR)=1.24 (95% CI: 0.90-1.71) and OR=1.61 (95% CI: 1.15-2.25) respectively, P for trend=0.004. Further adjustments for LGI or ED did not attenuate these associations. No such associations were found between Ln-HMGB1 and estimated glomerular filtration rate (eGFR), retinopathy or CVD, however. CONCLUSIONS: In type 1 diabetes, higher serum HMGB1 levels are associated with greater prevalence and severity of albuminuria, though not with eGFR, retinopathy and CVD. Prospective studies are needed to clarify the causal role of HMGB1, if any, in the pathogenesis of vascular complications in type 1 diabetes

Serum high-mobility group box-1 levels are positively associated with micro- and macroalbuminuria but not with cardiovascular disease in type 1 diabetes: the EURODIAB Prospective Complications Study

High-mobility group box-1 (HMGB1) is a pro-inflammatory cytokine that may contribute to the pathogenesis of micro- and macrovascular complications commonly observed in diabetes. We investigated whether HMGB1 is associated with: i) markers of low-grade inflammation (LGI) and endothelial dysfunction (ED) and pulse pressure (PP, a marker of arterial stiffness); ii) prevalent nephropathy, retinopathy and cardiovascular disease (CVD) in type 1 diabetes; and iii) the potential mediating roles of LGI, ED and PP therein