Measurement of 1H-1H dipolar couplings in macromolecules, weakly oriented by a dilute liquid crystalline medium, is generally limited to the largest such interactions. By removing dipolar couplings to nearest neighbors, either by decoupling, deuteration, or both, more remote interactions become accessible. The approach is demonstrated for measurement of amide-amide interactions in the proteins ...

Although a lot of progress has been made in Rhor Rucatalyzed asymmetric hydrogenation, Ir-catalyzed asymmetric hydrogenation is relatively unexplored.[1] Pfaltz and coworkers first reported several Ir-phosphinooxazoline complexes as catalysts for asymmetric hydrogenation. With leading efforts by Pfaltz and co-workers,[2] and Burgess and Experimental Section Representative experimental procedure...

BACKGROUND Flunarizine dihydrochloride (FLN) is used in the prophylactic treatment of migraine, vertigo, occlusive peripheral vascular disease and epilepsy. Cyclodextrins (CDs) are chiral, truncated cone shaped macrocycles known for their inner hydrophobic and outer hydrophilic site. They form complexes with hydrophobic drug molecules and enhance the solubility and bioavailability of such compo...

the coupling of tetrazotised 1,8-diaminonaphthalene with 1,3-dicarbonyl compounds [acetylacetone,methylacetoacetate and acetoacetanilide] yielded a new series of tetradentate ligand systems. analytical, ir,1h nmr and mass spectral data indicate that the compounds exist in the intramolecularly hydrogen bondeddihydrazone form. dibasic tetradentate n2o2 coordination of these compounds in their [ml...

methanesulfonic acid (msa) was found to be an efficient catalyst for the synthesis of 1-substituted-1h-1,2,3,4-tetrazoles. a series of 1-substituted tetrazole compounds were synthesized from the reaction of various primary amines, sodium azide and triethyl orthoformate in the presence of catalytic amounts of msa at room temperature. in this protocol, some of the tetrazole derivatives were synth...

Phytochemical studies on Galanthus elwesii resulted in the isolation of five alkaloids: incartine, hordenine, hippeastrine, 8-O-demethylhomolycorine and lycorine. The NMR data given previously for incartine were revised and completed by two-dimensional 1H-1H and 1H-13C chemical shift correlation experiments. In vitro studies on the bioactivity of incartine were carried out.

1-{β-[3-(4-Methoxy-phenyl)propoxy]-4-methoxyphenethyl}-1H-imidazole hydrochloride 7, or SKF-96365, was synthesized in four steps with an overall yield of 9%. The structure of 7 was confirmed by 1H-, 13C-NMR, HRMS, and elemental analysis. The intermediates 3 and 4 were also isolated and characterized by 1H-, 13C-NMR, and HRMS.

1H-1H and 31P-1H nuclear Overhauser effects and 31P NMR spin-lattice relaxation times were measured for a synthetic DNA poly(dA-dT).poly(dA-dT) in a low-salt aqueous solution. The results have shown that all bases in the double helix are anti-orientated with respect to deoxyribose residues and that the sugar-phosphate backbone has an alternating architecture.

Four new C-glucopyranosides of resveratrol oligomers, hemsleyanosides A-D, were isolated from the bark of Shorea hemsleyana. The structures were established on the basis of spectroscopic evidence, including 1H-1H and 1H-13C long-range couplings and nuclear Overhauser effect experiments in the NMR spectrum.

Six organometallic complexes of the general formula [M(II)Cl(η(6)-p-cymene)(L)]Cl, where M = Ru (11a, 12a, 13a) or Os (11b, 12b, 13b) and L = 3-(1H-benzimidazol-2-yl)-1H-pyrazolo[3,4-b]pyridines (L1-L3) have been synthesized. The latter are known as potential cyclin-dependent kinase (Cdk) inhibitors. All compounds have been comprehensively characterized by elemental analysis, one- and two-dimen...