Natural abundance 13C nuclear magnetic resonance spectroscopy was used to detect signals from glycogen in the human gastrocnemius muscle. The reproducibility of the measurement was demonstrated, and the ability to detect dynamic changes was confirmed by measuring a decrease in muscle glycogen levels after exercise and its subsequent repletion. Single frequency gated 1H decoupling was used to ob...

Lichens and spore-derived cultured mycobionts of Teloschistes chrysophthalmus and Ramalina celastri were studied chemically, and results indicated that they produced, respectively, parietin and usnic acid as major secondary metabolites, which were purified and identified. Identification of the compounds was performed by high performance liquid chromatography and structural elucidation by nuclea...

Phytochemical investigations on the stem bark and roots of the tropical shrub Clausena anisata led to the isolation and characterization three carbazole alkaloids: girinimbine, murrayamine-A and ekeberginine; two peptide derivatives: aurantiamide acetate and N-benzoyl-L-phenylalaninyl-N-benzoyl-L-phenylalaninate; and a mixture of two phytosterols: sitosterol and stigmasterol. The structures of ...

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...

The fungus Cunninghamella elegans was used to biotransform 6-nitrochrysene, a mutagen that is a widespread environmental contaminant. After 6 days, 74% of the 3H-labeled 6-nitrochrysene added had been metabolized to two isomeric sulfate conjugates. These conjugates were separated by high-performance liquid chromatography and identified by UV-visible, 1H nuclear magnetic resonance, and mass spec...

The chemical modifications of poly (vinyl chloride) with aliphatic and aromatic alcohols compounds have been investigated at room temperature and atmospheric pressure, catalysed by a new green basic catalyst, the Maghnite-K. The presence of ether groups in the products is proven by infra red spectroscopy (IR) as well as by nuclear magnetic resonance spectroscopy (1H NMR), and characterized by i...

Synthesis and characterization of new thiadiazoles, bisthiadiazoles from the reaction of mono- and di-hydrazonoyl halides with various hydrazinecarbodithioate derivatives were studied. Treatment of hydrazonoyl halides with 2,5-dihydrazinyl-1,3,4-thiadiazole afforded new bistriazines containing thiadiazole; we also examined the reaction of 2,5-dihydrazinyl-1,3,4-thiadiazole with active methylene...

An endogenous compound (included in the fraction of uremic toxins often called the "uremic middle molecules") was separated from plasma of uremic patients and urine from normal persons. As elucidated by mass spectrometry, enzymatic hydrolysis, and 1H, 13C nuclear magnetic resonance, it appears to be a conjugate of o-hydroxybenzoic acid with glucuronic acid. Its presence in urine of healthy subj...

31P- and 1H-nuclear magnetic resonance spectroscopy (MRS) are powerful tools for studying myocardial energy metabolism. The purpose of this review is to illustrate how these MRS techniques can be used to study complex bioenergetic issues in normal and abnormal in vivo myocardium. The results provide insight into the energetic alterations present in remodeled and hypertrophied myocardium. A deta...

Functional brain mapping with magnetic resonance imaging (MRI) is a rapidly growing field that has emerged in only the past several years. Functional MRI (fMRI) is the use of MRI equipment to detect regional changes cerebral metabolism or in blood flow, volume or oxygenation in response to task activation. The most popular technique utilizes blood oxygenation level dependent (BOLD) contrast, wh...