نتایج جستجو برای: dynamic 1h nmr
تعداد نتایج: 482449 فیلتر نتایج به سال:
N-Allyl-N-methyl-2-aminopropane (AMAP) is a relatively simple tertiary amine that has a chiral center at the pyramidal nitrogen. Racemization occurs by inversion-rotation at nitrogen. For each AMAP enantiomer, conformational exchanges occur via isolated rotation about carbon-nitrogen and carbon-carbon bonds. The 1H and 13C{1H} dynamic NMR (DNMR) spectra of AMAP show a higher temperature decoale...
Quantification of apoptotic cell death in vivo has become an important area of investigation in patients with acute lymphoblastic leukemia (ALL). We have devised a noninvasive analytical method to estimate the percentage of apoptotic lymphoblasts in doxorubicin-treated Jurkat T-cell ALL cultures, using proton nuclear magnetic resonance spectroscopy (1H NMR). We have found that the ratio of the ...
This article describes the synthesis and characterization of a novel 'schizophrenic' diblock copolymer [poly(2-succinyloxyethyl methacrylate)-b-poly[(N-4-vinylbenzyl),N,N-diethylamine)]; PSEMA-b-PVEA] via reversible addition of fragmentation chain transfer (RAFT) polymerization technique. The chemical structures of all samples as representatives were characterized by means of Fourier transform ...
113Cd-NMR studies have established that vertebrate and invertebrate metallothioneins contain two unique metal-thiolate clusters. However, it proved to be difficult to account theoretically for all features of the 113Cd-NMR spectra. In a reinvestigation of these features using chromatographically homogeneous 113Cd7-metallothionein we have identified a total of seven 113Cd resonances and have con...
BACKGROUND AND AIMS Proton nuclear magnetic resonance spectroscopy coupled multivariate analysis (1H NMR-PCA/PLS-DA) is an important tool for the discrimination of wine products. Although 1H NMR has been shown to discriminate wines of different cultivars, a grape genetic component of the discrimination has been inferred only from discrimination of cultivars of undefined genetic homology and in ...
A 1H NMR method for the quantification of dermatan sulfate impurities in heparin industrial samples is proposed. The method is based on the analysis of 1H NMR spectral data by multivariate calibration. The 1H NMR spectra of heparin and dermatan sulfate standards showed characteristic profiles. Thus, differences in the methyl peaks of acetamido groups of heparin and dermatan sulfate were greatly...
Silyl and acetyl derivatives of sporopollenin from the pollen of Typha angustifolia L. were prepared. The derivatized products were readily soluble in piperidine-d11 and could be investigated employing one- and two-dimensional proton and carbon NMR (nuclear magnetic resonance) spectroscopy (1H,1H-COSY and 13C,1H-HETCOR techniques). For the first time, a two dimensional 13C,1H-HETCOR NMR spectru...
Currently, the functional monomer 10-methacryloyloxy-decyl-dihydrogen-phosphate (10-MDP) was documented to chemically bond to zirconia ceramics. However, little research has been conducted to unravel the underlying mechanisms. This study aimed to assess the chemical interaction and to demonstrate the mechanisms of coordination between 10-MDP and zirconium oxide using 1H and 31P magic angle spin...
From the ethyl acetate soluble fraction of twigs of Magnolia denudata (Magnoliaceae), seven new neolignan derivatives, 1-7, were isolated along with eighteen known lignan and neolignan derivatives, 8-25. The structures of the new neolignans were elucidated by means of spectral methods, especially by 1H-NMR and 13C-NMR spectra, and two dimensional NMR methods such as 1H-detected heteronuculear m...
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