Two novel urea anion receptors (11) and (12) were synthesized from building block 3,3’ methylene diamine and was characterized via the techniques of 1H NMR, 13 C NMR, DEPT135 1H-1H COSY, HMQC and HMBC spectroscopy. The 1H NMR profile of both compounds reveals diagnostic peaks. For compound (11), the urea NH protons resonate as two singlets downfield at 8.706 ppm and 8.635 ppm, whereas for compo...

10B-enriched L-p-boronophenylalanine (BPA) is one of the compounds used in boron neutron capture therapy (BNCT). In this study, several variations of nuclear magnetic resonance spectroscopy (MRS) and spectroscopic imaging (MRSI) were applied to investigate the uptake, clearance and metabolism of the BPA-fructose complex (BPA-F) in normal mouse kidneys, rat oligodendroglioma xenografts, and rat ...

Urinary N,N,N-trimethylglycine (betaine) and N,N-dimethylglycine (DMG) have been identified and quantified for clinical purposes by proton nuclear magnetic resonance (1H NMR) measurement in previous studies. We have assessed these procedures by using both one-dimensional (1-D) and 2-D NMR spectroscopy, together with pH titration of urinary extracts to help assign 1H NMR spectral peaks. The beta...

Oxalic acid dihydrate as a green, mild and efficient catalyst for the one-pot three-component Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives from the reaction between β-keto esters (methyl or ethyl acetoacetate), aromatic aldehyde (benzaldehye derivatives) and urea or thiourea under thermal and solvent-free conditions with excellent yields and short reaction time is st...

Oxalic acid dihydrate as a green, mild and efficient catalyst for the one-pot three-component Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives from the reaction between β-keto esters (methyl or ethyl acetoacetate), aromatic aldehyde (benzaldehye derivatives) and urea or thiourea under thermal and solvent-free conditions with excellent yields and short reaction time is st...

1-substituted 1H-tetrazoles were efficiently synthesized under solvent-free conditions from the reaction of primary amines, triethylorthoformate, and sodium azide in the presence of Cu/C as a heterogeneous catalyst. Various amines including aromatic and heteroaromatic amines were used to afford the corresponding products in good to excellent yields. The characterization of corresponding product...

On the basis of spectroscopic investigations (1H-NMR, 13C-NMR, UV, IR and MS spectroscopy), elemental analysis and degradation reactions the structure of a new alkaloid discarine G from the bark extract of Discaria febrifuga Mart. is elucidated.

Magnetic resonance spectroscopy (MRS) noninvasively provides information on the concentration of some cerebral metabolites in vivo. Among those measurable by proton magnetic resonance spectroscopy (1H-MRS), N-acetyl-aspartate (NAA) is decreased, and myo-inositol (ml) and choline (Cho) levels are increased in patients with Alzheimer's disease (AD). Donepezil, an acetylcholinesteraze inhibitor, h...

The N1 imino units in Escherichia coli tRNAfMet, tRNAGlu, tRNAPhe, and tRNATyr were studied by 1H-15N NMR using three different techniques to suppress signals of protons not attached to 15N. Two of the procedures, Fourier internuclear difference spectroscopy and two-dimensional forbidden echo spectroscopy permitted 1H and 15N chemical shifts to be measured simultaneously at 1H sensitivity. The ...

The inhibition potential of four Quinoxaline derivatives namely 1,4-dihydroquinoxaline-2,3dione, (3E)-3-hydrazinylidene-3,4-dihydroquinoxalin-2(1H)-one, 1-[(2E)-3-oxo-3,4dihydroquinoxalin-2(1H)-ylidene]urea and 1-[(2E)-3-oxo-3,4-dihydroquinoxalin-2(1H)ylidene]thiourea have been investigated against mild steel in 1M H2SO4 solution using conventional weight loss, electrochemical impedance spectro...