The interaction between POCl(3) or POBr(3) and pyridine or DMAP has been reinvestigated to clarify the discrepancies between previously published results concerning the Lewis acidity of phosphoryl halides and their behavior toward pyridine bases. The obtained results show that POCl(3) virtually does not react with pyridine, while it does with 4-(dimethylamino)pyridine (DMAP), even in SO(2) solu...

Catalase is well-known as an antioxidant dismutating H2O2 to O2 and H2O. However, catalases evolved when metabolism was largely sulfur-based, long before O2 and reactive oxygen species (ROS) became abundant, suggesting catalase metabolizes reactive sulfide species (RSS). Here we examine catalase metabolism of H2Sn, the sulfur analog of H2O2, hydrogen sulfide (H2S) and other sulfur-bearing molec...

Nitric oxide (NO) and reactive oxygen intermediates (ROIs) play key roles in the activation of disease resistance mechanisms both in animals and plants. In animals NO cooperates with ROIs to kill tumor cells and for macrophage killing of bacteria. Such cytotoxic events occur because unregulated NO levels drive a diffusion-limited reaction with O(2)(-) to generate peroxynitrite (ONOO(-)), a medi...

Abstract Molecular β‐diketiminato (BDI) calcium hydride and n ‐hexyl derivatives are shown to display contrasting reactivities toward bis(pinacolato)diboron (B 2 pin ). Whereas the dimeric constitution of is retained during formation an unusual diborane(6) dianion, initially organocalcium reagent converted a diboranate monomer, [(BDI)Ca{pinB‐Bpin( ‐hex)}]. Attempts effect heterolysis B−B bond t...

Superoxide dismutase is an important antioxidant to control the free radical reactions related to superoxide generated in biological system. However, its large molecule and short lifespan in vivo limit its clinical use. Extensive studies have been carried out to find the suitable SOD-mimics to substitute it. In order to acts as SOD mimics, a compound should be non-toxic, stable, easy to reach i...