The methyl-methyl NOESY experiment plays an important role in determining the global folds of large proteins. Despite the high sensitivity of this experiment, the analysis of methyl-methyl NOEs is frequently hindered by the limited chemical shift dispersion of methyl groups, particularly methyl protons. This makes it difficult to unambiguously assign all of the methyl-methyl NOE crosspeaks usin...

A trehalose-containing glycolipid was detected in several strains of Mycobacterium fortuitum and characterized as 2,3-di-O-acyltrehalose (DAT) by combined NMR spectroscopy, IR spectroscopy, GLC and GLC-MS. Lipid constituents of the molecule were identified as a mixture of straight-chain (14-18 carbon atoms) and methyl-branched-chain (17-21 carbon atoms) fatty acyl groups. DAT was further fracti...

In the rat and other species “labile― methyl groups are essential to normal metabolism (5). These are methyl groups which are capable of be ing transferred in toto from one compound to an other by specific enzymes and enzyme cofactors. In the rat the major source of such groups is the diet, which may contain them in the form of such compounds as i@-methionine, choline, betaine, and possibly...

Methyl-transverse relaxation optimized spectroscopy is rapidly becoming the preferred NMR technique for probing structure and dynamics of very large proteins up to ~1 MDa in molecular size. Data interpretation, however, necessitates assignment of methyl groups which still presents a very challenging and time-consuming process. Here we demonstrate that, in combination with a known 3D structure, ...

Abstract Furans are an important class of compounds that can be thermochemical or enzymatically produced from biomass. Despite their importance little is known about the thermal decomposition furans with oxygenated substituents. In this work, influence -CH3, -CH2OH and -CHO functional groups on molecular radical chemistry studied a combined quantum chemical experimental approach using 2-furfury...

Since the original demonstrations by du Vigneaud et al. (l-4) that the methyl group of labeled methionine can be transferred intact to choline, considerable evidence has accumulated suggesting that this is not the only source of choline methyl groups. It was shown unequivocally that choline methyl groups can be synthesized de novo in germ-free rats receiving a diet devoid of methyl donors (5). ...

thiophosgene and 1-chloroethyl chlorothionoformate react readily with tertiary amines, and give the dialkylamine hydrochloride after hydrolysis of the initial product with water. benzyl and allyl groups are cleaved in preference to methyl and other alkyl groups. the rection with the isoquinoline alkaloid narcotine occurs particularly easily.

The microwave spectrum of 2,3-dimethylfluorobezene, one the six isomers dimethylfluorobenzene, was recorded using a pulsed molecular jet Fourier transform spectrometer operating in frequency range from 2 to 26.5 GHz. internal rotations two inequivalent methyl groups, causing splittings up several hundred MHz all rotational energy levels into quintets, were analyzed and modeled. torsional barrie...