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 ...

2D 1H-15N HMBC NMR acquired at natural abundance and DMSO titration monitored by 1D 1H NMR verified the existence of an intramolecular hydrogen bond that was designed to mimic the pyrimidinone ring of a class of kinase inhibitors. A scalar coupling across the hydrogen bond was detected in organic and aqueous solvent, suggesting a simple and general approach for testing the propensity of intramo...

Six novel chloro-containing 1-aryl-3-oxypyrazoles TMa-TMf with an oximino ester or an oximino amide moiety were prepared by the reaction of 1-aryl-1H-pyrazol-3-ols with benzyl bromide. Their structures were characterized by 1H-NMR, 13C-NMR, IR, MS, and elemental analysis. A preliminary in vitro bioassay indicated that compounds TMa, TMe and TMf displayed excellent fungicidal activity against Rh...

A new coumarin, edgeworic acid (1), was isolated from the flower buds of Edgeworthia chrysantha, together with the five known coumarins umbelliferone (2), 5,7-dimethoxycoumarin (3), daphnoretin (4), edgeworoside C (5), and edgeworoside A (6). Their structures were established on the basis of spectral data, particularly by the use of 1D NMR and several 2D shift-correlated NMR pulse sequences (1H...

The metabolism of 3-([3-(2-Chlorophenyl)-4,5-dihydro-5-thioxo-1H-1,2,4-triazol-1-yl]methyl)benzonitrile (AR-C133611XX) was studied in isolated dog hepatocytes. The major metabolite of AR-C133611XX was characterized by high performance liquid chromatography-mass spectrometry and NMR and found to be the product of direct glucuronidation. Evidence from 1H and 13C-NMR chemical shifts and a long-ran...

Experimental parameters that influence the resolution of 1H-NMR phenol OH signals are critically evaluated with emphasis on the effects of pH, temperature and nature of the solvents. Extremely sharp peaks (Δν1/2≤2 Hz) can be obtained under optimized experimental conditions which allow the application of 1H-13C HMBC-NMR experiments to reveal long range coupling constants of hydroxyl protons and,...

Nuclear magnetic resonance/liquid chromatography-mass spectroscopy parallel dynamic spectroscopy (NMR/LC-MS PDS) is a method aimed at the simultaneous structural identification of natural products in complex mixtures. In this study, the method is illustrated with respect to (1)H NMR and rapid resolution liquid chromatography-mass spectroscopy (RRLC-MS) data, acquired from the crude extract of A...

A series of methyl 6-Chloro-2-Substitued-1-[2-(1H-tetrazol-5-yl)-biphenyl-4-ylmethyl]1H-benzoimidazol-5-ylamine were successfully synthesized. Benzimidazoles were prepared by condensation of 4-chloro-o-phenylenediamine with substituted aryl, aldehyde condensation with biphenyl tetrazole group and reduction stannous chloride dihydrate. An insertion-cyclization strategy was involved during synthe...

the potential of tobacco waste as a viable source of medicinally important flavonoids like rutin has been investigated. three flavonoids, apigenin, quercetin and rutin, have been isolated from waste tobacco leaves, and their identities have been confirmed by uv-visible, 1h-nmr and 13c-nmr spectroscopy. by using analytical hplc, the amount of rutin present in the tobacco leaves, before and after...