The methyl group of nicotine has been shown to participate in transmethylation reactions involving methionine (3) and choline (8). De novo synthesis of radioactive nicotine from nornicotine, methioninemethyl-C14 and ATP was demonstrated recently in leaves of Nicotiana alata (9). In the present study the rate of metabolism of the methyl group of nicotinemethyl-C14 ancl the rate of transmethylati...

Substantial changes in the chemical shifts of some of the protons in the nuclear magnetic resonance (NMR) spectra of aldehydes and ketones are observed on going from chloro-form or carbon tetrachloride to benzene as solvent. This paper presented a model which correlates the sign and magnitude of these changes with the geometrical relationship between the protons and the carbonyl group. [The SCI...

The title compound, C20H47NO6Si4, was synthesized by per-O-tri-methyl-silylation of N-acetyl-d-glucosa-mine using chloro-tri-methyl-silane in the presence of hexa-methyl-disiloxane. The tri-methyl-silyl group and acetamido group are located on the same side of the pyran ring, showing an α-configuration glycoside. One of the tri-methyl-silyl groups is disordered over two orientations, with site-...