Honey is one of the oldest sweetening foods and has economic importance, making this product attractive to adulteration with cheap sugars. This can cause a critical problem in the honey industry and a possible health risk. The present work has the aim of evaluating the authenticity of honey commercialized in two different provinces of Ecuador (Pichincha and Loja) by performing physicochemical and spectroscopic analyses. For this study 25 samples were collected from different places and markets and characterized by water, sucrose, reducing sugars and electric conductivity measurement. Also, their Raman and Infrared (IR) spectra were recorded and analysed using a Principal Component Analysis (PCA) in order to verify the quality of the honeys. In addition, a screening of several pesticides was performed in order to verify possible chemical threats to human health and honey bees. It was found that 8 samples have a deviation from the Standard established parameters. Two of them have a high difference in the content of sucrose and reducing sugars, which are located deviated from all the other samples in the PCA of the applied vibrational spectroscopy (IR/Raman), shaping two clear clusters. The results show that Raman and IR spectroscopy is appropriate techniques for the quality control of honey and correlates well with the physicochemical analyses.
16 August 2019 in The Journal of Organic Chemistry
The intermolecular interactions in the solid state and the spectroscopic vibrational, electronic and NMR properties of new 3-methyl-substituted-2-trifluoromethylchromone derivatives with –CN (1), –NO2 (2), –OH (3) and –NH2 (4) groups were discussed with the assistance of DFT calculations. The crystal structures of compounds 1–3 were determined by X-ray diffraction showing molecular ribbons for compounds 1 and 2, and dimers via O–H⋯OC hydrogen bonds for 3. Hirshfeld surfaces and the corresponding fingerprint plots, as well as the electrostatic potentials mapped on the surfaces revealed C–H⋯O and C–H⋯F hydrogen bonds, and π⋯π stacking as the main cooperative driving forces for building supramolecular architectures in all compounds. The C–H⋯π and CO⋯π interactions also contribute to stabilizing the crystal structures of 1 and 2. A further analysis of Hirshfeld surfaces was performed using the enrichment ratio as a new descriptor to determine the likelihood of chemical species to establish specific interactions in the molecular packing. The lattice energies of the crystal structures and several intermolecular contacts present in different molecular pairs were also quantified. Molecular docking studies showed the interaction of the title compounds with the catalytic site of PLA2 (PDB code 2QOG) from Crotalus durissus terrificus, and suggested that the investigated compounds could inhibit toxic effects of snake venom.
5 March 2013 in The Journal of Physical Chemistry A