Synthesis and brain antihypoxic activity of some aliphatic and arylaliphatic amides of caffeine-8-thioglycolic acid

Int J of Quantum Chemistry

et al. 2012

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Nine biologically active theophylline derivatives were investigated using quantum chemical methods (density functional theory level). All calculations were performed at B3LYP/6‐31G** level of theory. The electrostatic potential charges, highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) gap, dipole moment, vibration frequencies, and electronic spectra were calculated. Log P was determined by Ghose‐Crippen method. All of the compounds under study are polar and negatively charged, which is necessary for their interaction with the receptors/enzymes. Majority of the compounds are lipophilic and they can easily diffuse through the cell membrane. The observed differences between the calculated and the experimental vibration frequencies in the Fourier Transform Infrared Spectroscopy (FTIR) spectra are established to be mainly in NH and OH bands, due to hydrogen bonds formation. The discrepancies between theoretical and experimental electronic spectra may be due to vibration effects and H‐bonding with the solvent molecules. The obtained results show that this type of spectrum is formed mainly by the xanthine fragment of the molecule, especially in the fingerprint region. All calculated properties could be useful for future qualitative‐structure activity relationship (QSAR) analysis. © 2012 Wiley Periodicals, Inc.

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“…Their synthesis has been described previously 16, 17. The preoptimized geometries (MM2 level) of all molecules were reoptimized at B3LYP/6‐31G** level.…”

Section: Resultsmentioning

confidence: 99%

“…In the following article, a density functional theory (DFT) study of the physicochemical characteristics and spectral behavior of nine newly synthesized 8‐substituted 1,3,7‐trimethylxanthines with brain antihypoxic activity is presented 16, 17…”

Section: Introductionmentioning

confidence: 99%

DFT study of the physicochemical characteristics and spectral behavior of new 8‐substituted 1,3,7‐trimethylxanthines

Stanchev

Int J of Quantum Chemistry

et al. 2012

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“…The test products were synthesized according to a procedure described elsewhere (Mitkov et al, , 2010; Figure 1). …”

Section: Resultsmentioning

confidence: 99%

Stability Evaluation of Caffeine-8-Thioglicolic Acid Amides, With Determined Antihypoxic Effects

Zlatkov

2017

CBUP

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This study evaluates a series of caffeine-8-thioglycolic acid amides that were synthesized in the study, for signs of possible degradation. The chemical stability of the test compounds was examined under different conditions of pH and temperature over time. A modified reversed phase-high-performance liquid chromatography method was applied to determine stability and identify possible degradation products. The study identified a new product from oxidative destruction of the test compound through controlled synthesis.UDC Classification: 615.3; DOI: http://dx

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“…Experimental procedures the synthesis and characterization of the studied compounds was described previously (15,16). the 1 h nMR spectra were measured on a Bruker 100WP (100 Mhz) spectrometer (Germany) using DMSo-d 6 as solvent and chemical shifts were expressed as δ values in ppm against tMS as an internal standard.…”

Section: Methodsmentioning

confidence: 99%

“…Based on the variety of pharmacological activities of the xanthine derivatives and their promising effects on a number of cnS degenerative diseases, it was of interest to enrich this moiety with some structural analogues. For this purpose we have successfully synthesized some low toxic caffeine (15,16), theophylline (23) and theobromine (24) derivatives with antihypoxic activity.…”

Section: Introductionmentioning

confidence: 99%

GIAO NMR Calculations of Some Novel 8-Thio-Substituted 1,3,7-Trimethylxanthines: Comparison of Theoretical and Experimental¹H Chemical Shifts

Stanchev

Biotechnology & Biotechnological Equipment

et al. 2012

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