The fragmentation of peptides containing quaternary ammonium group, but lacking easily mobilizable protons, was examined with the aid of deuterium-labeled analogs and quantum-chemical modeling. The fragmentation of oligoproline containing quaternary ammonium group involves the mobilization of hydrogens localized at α- and γ- or δ-carbon atoms in the pyrrolidine ring of proline. The study of the...

Since the discovery of deuterium,' there has been considerable interest in the preparation of a variety of compounds in which hydrogen has been replaced by this heavier isotope. Some of the research has centered around the synthesis of deuterated compounds for biological study.2 While not occupying a place of prominence in this work, the preparation of deuterated amino acids has been studied in...

Investigation of the metabolism and fate of steroid hormones has been greatly facilitated by isotope stably incorporated into the substance t,o be studied. For many purposes the isotopes of hydrogen are decidedly advantageous in that the chemical synthesis of the labeled steroid can be easily and quickly achieved with a minimum of manipulation. Moreover, since the endogenous pool of the hormone...

Background: This study aimed to evaluate the reaction of organism of laboratory animals on deuterium-depleted drinking diet. To assess the cell energy metabolism, the effect of a liquid medium with different deuterium contents on isolated liver mitochondria of random bred rats and Wistar rats was studied. Methods: This experimental study on the effect of deuterium-depleted drinking water (DDW) ...

Some compounds readily form [M+46]+ adduct ions during positive ion electrospray ionization mass spectrometry ((+)ESI-MS) analysis. These [M+46]+ ions were characterized as [M+CH3CH2NH2+H]+ by accurate mass determination. Ethylamine involved in the adduct was proposed to be the reduction product of acetonitrile and this was confirmed using deuterated acetonitrile. Other nitrile-containing compo...

Palladium-catalyzed oxidative annulations between phenols and alkenylcarboxylic acids produced a library of benzofuran compounds. Depending on the nature of the substitution of the phenol precursor, either 2,3-dialkylbenzofurans or 2-alkyl-3-methylene-2,3-dihydrobenzofurans can be synthesized with excellent regioselectivity. Reactions between conjugated 5-phenylpenta-2,4-dienoic acids and pheno...

During growth on fully deuterated medium the volatile terpene [(2)H26]-1-epi-cubenol was released by the actinomycete Streptomyces griseus. This compound represents the first completely deuterated terpene obtained by fermentation. Despite a few previous reports in the literature the operability of this approach to fully deuterated compounds is still surprising, because the strong kinetic isotop...

The metabolism in the living rat of formaldehyde, doubly labeled with deuterium and *‘C, was investigated previously in this laboratory (1). In the forementioned studies, the double labeling was accomplished by admixture of two preparations of formaldehyde, one labeled with deuterium, the other with 14C. This type of double labeling has been referred to as intimolecular (3, 4). The results obta...