The field of zero- to ultralow-field (ZULF) nuclear magnetic resonance (NMR) is currently experiencing a rapid growth, owing the progress in optical magnetometry, and also attractive features ZULF NMR, such as low hardware cost excellent spectral resolution achieved under conditions. In this work, an approach proposed demonstrated for simultaneous acquisition ZULF-NMR spectra individual 13C-con...

The formation of monovalent and divalent salt complexes of maduramicin is described and the 13C NMR chemical shift assignments of these materials are tabulated and discussed. In the spectrum of the thallium salt, 20 of the 47 signals are split due to the thallium-carbon coupling. Similarly the preparation of both the free acid and the sodium salt complexes of the normal methyl and ethyl ketal d...

Indirect detection of 13C and 15N nuclear magnetic resonance (NMR) spectra through 1H NMR signals offers large sensitivity advantages in studies of organic and biological molecules in solution and is almost universally employed.1-3 Although sensitivity enhancement by indirect detection was first demonstrated in NMR4-6 and nuclear quadrupole resonance7,8 of solids, direct detection has generally...

the imine intermediate generated by the addition of primary amine to the cinnamaldehyde is trapped by the n-isocyaniminotriphenylphosphorane (ph3pnnc) and a carboxylic acid, and leads to the formation of the corresponding iminophosphorane intermediate. the 1,3,4-oxadiazole derivatives are formed via intramolecular aza-wittig reaction of the iminophosphorane intermediate. the reactions were comp...

a general synthetic route to the synthesis of imidazoles has been developed using nano sbcl5/sio2 under solvent-free conditions. the multi-component reactions of aldehydes, benzil and ammonium acetate were carried out to afford some trisubstituted imidazole derivatives. this method provides several advantages like simple work-up, environmentally benign, and shorter reaction times along with hig...

in this research, so3h-functionalizedphthalimide (sfp) has been prepared through simple reaction of phthalimide with chlorosulfonic acid, and characterized using ft-ir, 1h nmr, 13c nmr, sem (scanning electron microscopy), mass and tg (thermal gravimetric) spectra. afterward, the solid acid has been utilized as an efficient, green, heterogeneous and recyclable catalyst for the solvent-free synth...

Biosynthetic pathways of ebelactone A and B were studied by 13C NMR spectroscopy. By using 13C labeled compounds as precursors it was determined that ebelactone A was derived from one molecule of acetic acid and six propionic acids and ebelactone B from one molecule of acetic acid, five propionic acids and one butyric acid.

The biosynthesis of benastatin A, produced by Streptomyces sp. MI384-DF12, has been studied by feeding experiments with 14C- and 13C-labeled compounds followed by measurement of radioactivity and 13C NMR analysis. The results indicate that benastatin A is derived from two methionine units and fourteen acetate units, condensed in the "head-to-tail" fashion of typical polyketide biosynthesis.