acterizing free radicals in chemistry, biology and medicine, is detection by EPR spectroscopy. However, due to their high reactivity and short half-lives, direct EPR detection of many free radicals (e.g., superoxide, hydroxyl radical, alkyl radicals, etc.) is virtually impossible in solution at room temperature. Spin trapping is a technique developed in the late 1960s in which a nitrone or nitr...

The present study was carried out to evaluate the antimicrobial and antioxidant activities of methanol extract of Careya arborea (MECA) stem barks (Myrtaceae) in various in-vitro systems. Antimicrobial activities of MECA were carried out using disc diffusion methods with Gram positive and Gram negative bacteria and some fungal species. MECA showed broad-spectrum antimicrobial activity against a...

Retinyl acetate suppressed the free radical-induced oxidation of methyl linoleate. Retinyl acetate was reacted with an alkylperoxyl radical in two solvent systems, methanol and benzene, The alkylperoxyl radical was generated by the thermal decompositien of a free radical initiator, 2 2'-azobis(2,4-dimethylyaleronitrile), at 370C. The reaction products were isolated by HPLC and their structures ...

Multiwalled carbon nanotubes (MWCNTs) have been functionalized with -SO3H groups using new three steps chemical routes. Firstly, OH groups have been attached to CNT surfaces through a radical reaction. The second step involves converting the hydroxyl groups into the oxide one and last step included the attachment of –SO3H groups on the MWCNTs surfaces in the presence of 1-butyl-3-methyl imidazo...

The present study was carried out to evaluate the antioxidant and free radical scavenging activity of methanolic extract of Ervatamia coronaria leaves (Apocynaceae) in various systems. DPPH radical, superoxide anion radical, nitric oxide radical and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract. The antioxidant activity of methanolic ex...

The present study was carried out to evaluate the antioxidant and free radical scavenging activity of methanolic extract of Ervatamia coronaria leaves (Apocynaceae) in various systems. DPPH radical, superoxide anion radical, nitric oxide radical and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract. The antioxidant activity of methanolic ex...

This paper presents an experimental study of the self-initiation reaction of n-butyl acrylate (n-BA) in free-radical polymerization. For the first time, the frequency factor and activation energy of the monomer self-initiation reaction are estimated from measurements of n-BA conversion in free-radical homo-polymerization initiated only by the monomer. The estimation was carried out using a macr...

Ribonucleoside diphosphate reductase is an allosteric enzyme consisting of two nonidentical subunits, proteins B1 and B2. B1 contains dithiols which participate in the oxidation-reduction reactions of electron transport, while B2 contains a free radical essential for activity. Ribonucleoside diphosphates are bound to B1 but not to B2. Addition of 2'-deoxy-2'-chloro ribonucleoside diphosphates t...