Glutathione Synthesis Is Not Involved in Protection by N-Acetyl cysteine Against UVB-lnduced Systemic Immunosuppression in Mice

The photophysics of 5,10,15,20-tetraarylethynylporphyrinatozinc(II) complexes, 1 and 2, are reported. Compared to 5,10,15,20-tetraphenylporphyrinatozinc(II) (ZnTPP), the UV/visible spectra of 1 and 2 have red-shifted B and Q bands, with the Q bands of increased intensity relative to the B band. FIuorescence quantum yields and lifetimes and triplet quantum yields and lifetimes are similar to ZnTPP. However, quantum yields for in vitro singlet-oxygen generation are much larger than for ZnTPP and for 2 the quantum yield is near unity. These findings suggest that the title compounds could be potential lead compounds as sensitizers for photodynamic therapy.     

Synthesis of (E)- and (Z)-fluoro-olefin analogues of potent dipeptidyl peptidase IV inhibitors

(E)- and (Z)-fluoro-olefin analogues of potent dipeptidyl peptidase IV inhibitors were synthesized. A Wadsworth-Horner-Emmons reaction, followed by amide formation and reduction of the amide were used for the construction of the α-fluoro-α,β-unsaturated amine functionality.     

The CeO(2)(+) Cation: Gas-Phase Reactivity and Electronic Structure

"Bare" CeO(2)(+) ions can be prepared in the gas phase by consecutive oxidation of Ce(+) with O(2) and NO(2). The ability to activate saturated and unsaturated hydrocarbons is investigated by use of Fourier-transform ion cyclotron resonance mass spectrometry. In the reactions of CeO(2)(+) with linear and branched alkanes C-H bond activation is observed almost exclusively. In contrast, both oxygen-atom transfer and C-H bond activation processes occur when thermalized CeO(2)(+) cations react with simple alkenes and aromatic compounds. C-C bond activation is not observed at all. Insight into the structural and electronic properties of neutral CeO(2) and cationic CeO(2)(+) is provided by means of quasirelativistic density-functional and ab initio pseudopotential calculations. They reveal a (2)Sigma(u)(+) ground state for CeO(2)(+) which is best described as a linear cerium dioxide with a resonating pi bond. Finally, we discuss the influence of oxo ligands on the chemistry of the cationic CeO(n)()(+) (n = 0-2) species toward hydrocarbons.