Thermodynamics of Anion Binding by Chalcogen Bonding Receptors

The application of chalcogen bonding (ChB) to anion recognition is an underdeveloped area of host-guest supramolecular chemistry. The chemical instability of heavier chalcogen derivatives may in part be responsible for the lack of progress. Herein, the synthesis of a new structurally simple, tellurium-based ChB binding motif is reported, the robust stability of which has enabled the thermodynamic properties for ChB halide anion binding in polar aprotic and wet protic organic solvent media to be elucidated. The thermodynamic data reveals how the subtle interplay between ChB host, anion guest and solvent dictates halide binding selectivity and affinity trends. These findings help to provide a deeper insight into the nature of the ChB-anion interaction.

Circulating vitamin D levels are associated with the presence and severity of coronary artery disease but not peripheral arterial disease in patients undergoing coronary angiography

BACKGROUND AND AIMS

To investigate the association between vitamin D levels, angiographic severity of coronary artery disease, arterial stiffness and degree of peripheral arterial disease (PAD) as assessed by ankle brachial index (ABI).

METHODS AND RESULTS

375 patients undergoing coronary angiography from November 2012 to September 2013 were recruited. Serum 25-hydroxyvitamin D (25OHD) levels were measured as were ABI and pulse wave velocity (PWV). Based on the findings of the coronary angiogram, patients were divided into subgroups: Absent, Single, Double and Triple Vessel Disease (as defined by >50% stenosis in each major coronary artery) 0.275 patients not taking vitamin D supplements were included in the analysis. Mean age was 66.0 ± 11.2 (mean ± SD) years. Levels of 25(OH)D were significantly lower in patients with CAD when compared to patients without CAD (57.0 ± 1.73 versus 70.1 ± 2.46 nmol/L; p < 0.01). One way ANOVA revealed triple vessel disease patients had significantly lower 25(OH)D levels when compared to single vessel disease patients (50.6 ± 2.84 nmol/L versus 61.3 ± 3.16 p < 0.01) and trended to be lower when compared to double vessel disease patients (50.6 ± 2.84 versus 59.0 ± 2.99 nmol/L; p = 0.07). Stepwise regression revealed that age, gender (male), hypertension, hyperlipidemia and 25(OH)D were significant predictors of CAD (p < 0.05). Vitamin D was the most significant predictor for CAD (p < 0.001) There was no correlation between 25(OH)D levels, ABI and PWV.

CONCLUSION

Among patients presenting for coronary angiography, low serum 25-hydroxyvitamin D levels are associated with the presence and extent of angiographic CAD but not arterial stiffness or PAD.