Natural products provide excellent potential leads for drug development because of their chemical diversity and biological functionality. However, the productivity of discovery of new, pharmacologically active natural products has traditionally been low due to inherent difficulties and costs associated with extract dereplication, i.e., isolation, purification and structure elucidation of indivi...

in this research, the microstructural of low molecular weight 1,2-polybutadiene (1,2-pbd) was conducted by 1h and 13c nuclear magnetic resonance spectroscopy (nmr) to determine the isomeric contents of 1,4-cis, 1,4-trans and 1,2-vinyl in 1,2-pbd polymer structures. number average molecular weight for low molecular weight 1,2-pbd was measured by nmr techniques and the results were compared with ...

in this study the chemical properties of b6c4si and c16 clusters connected vitamin c have been investigated using density functional theory (dft). nmr parameters and homo- lumo gap energy are calculated by using density functional method (b3lyp) with 6-311g* basis set. calculations show that homo- lumo gap energy of vitamin c decreases after connecting to b6c4si or c16 cluster decreasing of hom...

body's iterative force-field computer program has been used to calculate strain energies in cyclooctanone (i). 348 mhz 1h nmr spectra of (i) have been investigated over the temperature range of 25° to -160°c. two conformation processes affect the 1h nmr spectrum of (i). iterative force-field calculations on the conformations and conformational interconversion paths of (i) give results consisten...

aprotic diazotization of anthranilic acid with isoamylnitrite or amylnitrite gave benzenediazonium-2- carboxylate. subsequent thermal decomposition of this diazonium salt (in situ) in 1,2-dichloroethane as a solvent at 85oc and in the presence of 2,5-diethyl-3,4-diphenylcyclopentadienonaes a trapping agent gave 1,4-diethyl-2, 3-diphenylnaphthalene in high yield, after loss of carbon monoxide. a...

α-acyloxycarboxamides are synthesized from three component Passerini reaction between indane-1,2,3-trione, isocyanides, and thiophenecarboxylic acids in quantitative yields. The structures of the final products were confirmed by IR, 1H and 13C NMR spectroscopy, mass spectrometry, and elemental analysis. The B3LYP/HF calculations for computation of 1H an...

Since the development bloom in unconventional reservoirs in North America, total organic carbon (TOC) has become a more essential parameter, as the indicator of the efficiency of these reservoirs. In this paper, by using conventional well logs and NMR log data, the TOC content of an unconventional reservoir in West Africa is estimated. Passy’s, Issler’s, and Schmoker’s methods were used as indi...