INTRODUCTION Hyperglycemia plays an important role in the pathogenesis of diabetic complications, as it increases protein glycation, as well as the progressive accumulation of advanced glycation end products (AGEs), which are complex structures that produce fluorescence. The glycation reaction raises the levels of protein carbonyl, N ε-(carboxymethyl)lysine (CML), and fructosamine and decreases...

We have performed an experimental investigation on the effects of hydrazine treatment on graphene oxide via a reaction-model approach. Hydrazine was reacted with small conjugated aromatic compounds containing various oxygen functional groups to mimic the structure of graphene oxide. The hydroxyl and carboxylic groups were not readily removed while carbonyl groups reacted with hydrazine to form ...

The intrinsic gas-phase reactivity of cyclic N-acyliminium ions in Mannich-type reactions with the parent enol silane, vinyloxytrimethylsilane, has been investigated by double- and triple-stage pentaquadrupole mass spectrometric experiments. Remarkably distinct reactivities are observed for cyclic N-acyliminium ions bearing either endocyclic or exocyclic carbonyl groups. NH-Acyliminium ions wit...

In maize leaves growth at low temperatures causes decreases in maximum catalytic activities of photosynthetic enzymes and reduced amounts of proteins, rather than effects on regulation or co-ordination of the photosynthetic processes. To test the hypothesis that differential localization of antioxidants between the different types of photosynthetic cell in maize leaves is a major determinant of...

Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (...

Comparison of theoretical and experimental structural parameters as well as nu(CO) frequencies for Os(3)(CO)(12) suggests that the density functional theory (DFT) method MPW1PW91 with a suitable ECP basis set including relativistic effects is a reliable method for predicting structures and vibrational frequencies of third row transition metal carbonyl derivatives. Using this method the structur...

In the title compounds, C(10)H(8)N(2)O(2), (I), and C(12)H(12)N(2)O(2), (II), the two carbonyl groups are oriented with torsion angles of -149.3 (3) and -88.55 (15)°, respectively. The single-bond distances linking the two carbonyl groups are 1.528 (4) and 1.5298 (17) Å, respectively. In (I), the molecules are linked by an elaborate system of N-H···O hydrogen bonds, which form adjacent R(2)(2)(...

The title mol-ecule, C22H17F3N2OS, adopts a trans-cis conformation with respect to the positions of the carbonyl and tri-fluoro-methyl-benzene groups against the thio-carbonyl group across the C-N bonds. The mol-ecular structure is stabilized by an intra-molecular N-H⋯O hydrogen bond with an S(6) ring motif. The tri-fluoro-methyl-substituted benzene ring forms dihedral angles of 66.05 (9) and 4...

Raman spectra of the cyclic hexapeptide cyclo-(L-prolylglycyl)3 and its Na+, K+, and Ca2+ complexes are reported for the solid state and for samples in solution. Model compounds and N-deuteration were used to aid mode identification. Spectra of the uncomplexed ionophore in solution are consistent with previously proposed solution conformations and permit the identification of spectral lines cha...

A detailed in situ infrared spectroscopy analysis of single layer and multilayered graphene oxide (GO) thin films reveals that the normalized infrared absorption in the carbonyl region is substantially higher in multilayered GO upon mild annealing. These results highlight the fact that the reduction chemistry of multilayered GO is dramatically different from the single layer GO due to the prese...