In analogy with the reaction of phenols very strong super acids, these compounds can be protonated by weaker acid trifluoroacetic (TFA) and trifluoromethanesulphonic (TFS) also giving rise to formation OH and/or ring products, which identified unambiguously means 1HNMR spectroscopy. The same reactions are possible deuterated acids TFA-d TFS-d. However, from reactions, additional information on ...

We previously identified five derivatives of Klenow fragment DNA polymerase that have lower fidelity because of amino acid substitutions in the polymerase active site. One of these has alanine substituted for the invariant Glu-710, whose side chain interacts with the deoxyribose of the incoming dNTP. Here we show that the E710A enzyme has reduced fidelity for five of the 12 possible mismatches....

Carotenoids are thought to act as antioxidants in vivo, decreasing oxidative damage to biomolecules and thus protecting against coronary heart disease and cancer. However, human intervention studies with beta-carotene have given equivocal results in terms of cancer incidence. In an alternative molecular epidemiological approach, we have employed the 'comet assay' (single cell alkaline gel elect...

Recent studies on the fate of labeled dietary purines in the rat have shown t,hat dietary adenine is a precursor of t,he adenine and of the guanine of tissue nucleic acids (l), but that guanine (2), hypoxanthine (3), and xanthine (3) are not utilized for nucleic acid synthesis. Similar experiments have shown that the pyrimidines, uracil, thymine (2), and cytosine (4) are not incorporated into t...

The 2H NMR transverse relaxation rates of a deuterated phospholipid bilayer reflect slow motions in the bilayer membrane. A study of dimyristoyl lecithin specifically deuterated at several positions of the hydrocarbon chains indicates that these motions are cooperative and are confined to the hydrocarbon chains of the lipid bilayer. However, lipid head group interactions do play an important ro...

ND2H has been detected for the first time in the dense core of L134N, at the peak ammonia position. The abundance ratio [ND2H]/[NH2D] is 0.05, a slightly smaller value than the deuterium fractionation observed for ammonia [NH2D]/[NH3] ∼ 0.1 (Tiné et al. 2000). This is the second doubly deuterated species detected so far in the interstellar medium, and the first one in a cold dense core. The che...