Theoretical calculations on the gas-phase thermal decomposition of dimethyldiazirine, diethyldiazirine and difluorodiazirine have been carried out using ab initio composite methods CBS-QB3 and G3, and DFT CAM-B3LYP, MPW1PW91, PBE1PBE and M062X. Reasonable agreement has been found with the experimental values by the G3 method. Two possible mechanisms were studied: Mechanism A consists the openin...

Biological nitrogen fixation (BNF) represents the natural pathway by which mosses meet their demands for bioavailable/reactive (Nr) in peatlands. However, following intensification of fertilizer and fossil fuel use, atmospheric Nr deposition has increased exposing peatlands to loading often above ecological threshold. As BNF is energy intensive, therefore, it unclear whether shuts down when ava...

Oxidative stress is defined as the imbalance between reactive species such as free radicals and oxidants and the antioxidant defenses. Free radicals are molecules with one or more unpaired electrons, while oxidants are molecules with a high potential for taking electrons from other molecules. The more recognized reactive species are the reactive oxygen species (ROS), which include oxygen and it...

The aim of this study was to determine the antioxidant properties of 6,7-dihydroxy-3,4-dihydroiso- quinoline-3-carboxylic acid (1) and its derivatives in living cells against reactive forms of oxygen and nitrogen, i.e., hydrogen peroxide and nitric oxide. Four of tested compounds scavenged the reactive form of nitrogen more efficiently or similarly to Trolox (EC50 = 55.80 µM). Two compounds exh...

This article provides a succinct but limited overview of the protective and deleterious effects of reactive oxygen and nitrogen species in a clinical context. Reactive oxygen species include superoxide, hydrogen peroxide, single oxygen and lipid peroxides. Reactive nitrogen species include species derived from nitric oxide. This review gives a brief overview of the reaction chemistry of these s...

Mitochondrial DNA (mtDNA) mutations have been found in many cancers but the physiological derangements caused by such mutations have remained elusive. Prostate cancer is associated with both inherited and somatic mutations in the cytochrome c oxidase (COI) gene. We present a prostate cancer patient-derived rare heteroplasmic mutation of this gene, part of mitochondrial respiratory complex IV. F...

The SecA protein is present in all bacteria, and it is a central component of the general Sec-dependent protein export pathway. An unusual property of Mycobacterium tuberculosis is the presence of two SecA proteins: SecA1, the essential "housekeeping" SecA, and SecA2, the accessory secretion factor. Here, we report that a DeltasecA2 mutant of M. tuberculosis was defective for growth in the earl...