the forced degradation study of lidocaine hcl was carried out according to the ich guideline q1a (r2). the degradation conditions were assessed to be hydrolysis, oxidation, photolysis and dry heat during 24 h, 48 h and 72 h and then the samples were investigated by gc-fid method and nuclear magnetic resonance (nmr) spectroscopy. according to these results, the degradation products were not obse...

Continuous flow 13C NMR spectroscopy has been used for the first time to monitor the metabolism of a 13C labeled drug in an isolated liver. Continuous and almost immediate information on the metabolite formation could be obtained using 13C labeled phenacetin without alteration of the biological system. The data are consistent with those observed by conventional techniques (HPLC, aliquot 13C NMR...

Phytochemical constituents of Asparagus adscendens and Asparagus racemosus are being reported in the present communication. Two new sarsasapogenin glycosides have been isolated, one from each of the species. Structure elucidation of 1 and 10 has been accomplished through the extensive use of 1Dand 2D-NMR experiments including H-H (DQFCOSY), H-C (HMQC, HMBC) spectroscopy along with mass spectros...

Echinacoside (ECH) is one of the major active phenylethanoid glycosides (PEGs) in famous traditional Chinese medicine, Herba Cistanches. Although it has various bioactivities, such as antioxidation, neuroprotection, and hepatoprotection, knowledge about its metabolic fate is scant. In the present study, eight phase II metabolites, 3,4 -O-dimethyl-ECH-3 -O-beta-d-glucuronide (M1); 4,4 -O-dimethy...

Parallel receiving technologies have recently crossed the boundary separating magnetic resonance imaging from nuclear magnetic resonance (NMR) spectroscopy. In the latter case they promise significant time-saving advantages, by enabling the detection of multiple spectra simultaneously rather than in series. Moreover the full compatibility of parallel receiving with all other advances of contemp...

Nuclear magnetic resonance (NMR) spectroscopy enables non-invasive chemical studies of intact living matter. However, the use of NMR at the volume scale typical of microorganisms is hindered by sensitivity limitations, and experiments on single intact organisms have so far been limited to entities having volumes larger than 5 nL. Here we show NMR spectroscopy experiments conducted on single int...

The development of nuclear magnetic resonance (NMR) spectroscopy as an established research tool for noninvasive studies of cancer cells and for in vivo studies of tumors in animals and humans has led to the possibility that this technique may be used in the future for clinical research studies and monitoring of therapy in cancer patients in combination with magnetic resonance imaging. This art...

Deuterium (2H) double-quantum filtered (DQF) NMR spectroscopy of nucleus pulposus (NP) tissues from human intervertebral discs is reported. The DQF spectral intensities, DQ build-up rates, and DQF-detected rotating-frame spin-lattice relaxation times are sensitive to the degree of hydration of the NP tissue, and display a monotonous correlation with age between 15 and 80 years. The implications...

Assessing how excipients affect the self-association of monoclonal antibodies (mAbs) requires informative and direct in situ measurements for highly concentrated solutions, without sample dilution or perturbation. This study explores the application of solution nuclear magnetic resonance (NMR) spectroscopy for characterization of typical mAb behavior in formulations containing arginine glutamat...

Spectroscopy with conventional nuclear magnetic resonance (NMR) requires large, expensive, superconducting magnets cooled by liquid helium, like the one in the background. The Pines and Budker groups have demonstrated NMR spectroscopy with a device only a few centimeters high, using no magnets at all (foreground). A chemical sample in the test tube (green) is polarized by introducing hydrogen g...