We have studied and characterized the structure of hydrolysable tannins of commercial powder tara, performed by means ultra-high-resolution mass spectrometry (MALDI/FT-ICR) without using separation techniques. Our experimental results, supported by computational calculations at DFT/ M05-2X level of theory, show that the identified species are basically oligomeric structures of polygalloyquinic acids, of the (C7H4O4)n(C7H12O6) type, composed by a chain of polygallic esters (depside) linked, via ester bond, to one quinic acid.

In this work thermophysical and thermochemical properties of dried commercial maca flour were studied by combustion calorimetry and differential scanning calorimetry (DSC). Net calorific value or combustion massic energy (419 ± 3 Kcal/100 g); specific heats (between -4 and 70 °C) where c.e. for 25 °C is 1.46 ± 0.03 J/g.°C; and thermal parameters, such as temperature and enthalpy, of decomposition (Tmax = 210.1 ± 0.4 °C, ΔHdec 82 ± 10 J/g) and gelatinization (Tp = 76.9 ± 0.4 °C, ΔHgel = 5.6 ± 0.5 J/g) processes were evaluated.

Four indole-3-carbaldehyde semicarbazone derivatives, 2-((5-bromo-1H-indol-3-yl)methylene)hydrazinecarboxamide (1), 2-((5-chloro-1H-indol-3-yl)methylene)hydrazinecarboxamide (2), 2-((5-methoxy-1H-indol-3-yl)methylene)hydrazinecarboxamide (3), and 2-((4-nitro-1H-indol-3-yl)methylene)hydrazinecarboxamide (4) were synthesized and characterized by ESI-MS and spectroscopic (FT-IR, 1H NMR, and 13C NMR) techniques. The two-dimensional NMR (in acetone-d6) spectral data revealed that the molecules 1 and 2 in solution are in the cisE isomeric form. This evidence is supported by DFT calculations at the B3LYP/6-311++G(d,p) level of theory where it was shown that the corresponding most stable conformers of the synthesized compounds have a cisE geometrical configuration, in both the gas and liquid (acetone and DMSO) phases. The in vitro antibacterial activity of compounds 1–4 was determined against ...

Eight new phenylisoxazole isoniazid derivatives, 3-(2'-fluorophenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (1), 3-(2'-methoxyphenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (2), 3-(2'-chlorophenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (3), 3-(3'-clorophenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (4), 3-(4'-bromophenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (5), 5-(4'-methoxiphenyl)isoxazole-3-carbaldehyde isonicotinylhydrazone (6), 5-(4'-methylphenyl)isoxazole-3-carbaldehyde isonicotinylhydrazone (7), and 5-(4'-clorophenyl)isoxazole-3-carbaldehyde isonicotinylhydrazone (8), have been synthesized and characterized by FT-IR, 1H-NMR, 13C-NMR, and mass spectral data. The 2D NMR (1H-1H NOESY) analysis of 1 and 2 confirmed that these compounds in acetone-d6 are in the trans(E) isomeric form. This evidence is supported by computational calculations which w...