Boronate-Based Bioactive Compounds Activated by Peroxynitrite and Hydrogen Peroxide.

Boronates react directly and stoichiometrically with peroxynitrite and hydrogen peroxide. For this reason, boronates have been widely used as peroxynitrite- and hydrogen peroxide-sensitive moieties in various donors of bioactive compounds. So far, numerous boronate-based prodrugs and theranostics have been developed, characterized, and used in biological research.

The Chemistry of HNO: Mechanisms and Reaction Kinetics.

Azanone (HNO, also known as nitroxyl) is the protonated form of the product of one-electron reduction of nitric oxide (NO), and an elusive electrophilic reactive nitrogen species of increasing pharmacological significance. Over the past 20 years, the interest in the biological chemistry of HNO has increased significantly due to the numerous beneficial pharmacological effects of its donors. Increased availability of various HNO donors was accompanied by great progress in the understanding of HNO chemistry and chemical biology.

Kinetics of Azanone (HNO) Reactions with Thiols: Effect of pH.

HNO (nitroxyl, IUPAC name azanone) is an electrophilic reactive nitrogen species of growing pharmacological and biological significance. Here, we present data on the pH-dependent kinetics of azanone reactions with the low molecular thiols glutathione and N-acetylcysteine, as well as with important serum proteins: bovine serum albumin and human serum albumin. The competition kinetics method used is based on two parallel HNO reactions: with RSH/RS or with O.

Oxidation of ethidium-based probes by biological radicals: mechanism, kinetics and implications for the detection of superoxide.

Hydroethidine (HE) and hydropropidine ([Formula: see text]) are fluorogenic probes used for the detection of the intra- and extracellular superoxide radical anion ([Formula: see text]). In this study, we provide evidence that HE and [Formula: see text] react rapidly with the biologically relevant radicals, including the hydroxyl radical, peroxyl radicals, the trioxidocarbonate radical anion, nitrogen dioxide, and the glutathionyl radical, via one-electron oxidation, forming the corresponding radical cations. At physiological pH, the radical cations of the probes react rapidly with [Formula: see text], leading to the specific 2-hydroxylated cationic products.

Boronate-Based Probes for Biological Oxidants: A Novel Class of Molecular Tools for Redox Biology.

Boronate-based molecular probes are emerging as one of the most effective tools for detection and quantitation of peroxynitrite and hydroperoxides. This review discusses the chemical reactivity of boronate compounds in the context of their use for detection of biological oxidants, and presents examples of the practical use of those probes in selected chemical, enzymatic, and biological systems. The particular reactivity of boronates toward nucleophilic oxidants makes them a distinct class of probes for redox biology studies.

Decomposition of Piloty's acid derivatives - Toward the understanding of factors controlling HNO release.

The recent interest in the clinical applications of Piloty's acid derivatives as HNO donors for the treatment of cardiovascular system dysfunction has led us to the examination of factors controlling HNO release from selected ortho-substituted N-hydroxysulfonamides. Here we present the kinetic and quantum mechanical studies on the mechanism of HNO release from selected ortho-substituted N-hydroxysulfonamides and in vivo examination of the antiaggregatory properties of N-hydroxy-(2-bromobenzene)sulfonamide complex with sodium salt of β-cyclodextrin sulfobutyl ethers-ethyl ethers as compared with Angeli's salt.

Fluorescent probes for the detection of nitroxyl (HNO).

Nitroxyl (HNO), which according to the IUPAC recommended nomenclature should be named azanone, is the protonated one-electron reduction product of nitric oxide. Recently, it has gained a considerable attention due to the interesting pharmacological effects of its donors. Although there has been great progress in the understanding of HNO chemistry and chemical biology, it still remains the most elusive reactive nitrogen species, and its selective detection is a real challenge.

A kinetic study on the reactivity of azanone (HNO) toward its selected scavengers: Insight into its chemistry and detection.

Recently, azanone (HNO), which is the protonated one-electron reduction product of NO, has gained considerable attention due to its unique pharmacological effects. Although there has been much progress in understanding HNO biology and chemistry, it remains the most elusive reactive nitrogen species. Herein, we applied the competition kinetics method, based on two parallel HNO reactions with the different scavengers and molecular oxygen (k = (1.