We previously showed that H2 acts as a novel antioxidant to protect cells against oxidative stress. Subsequently, numerous studies have indicated the potential applications of H2 in therapeutic and preventive medicine. Moreover, H2 regulates various signal transduction pathways and the expression of many genes. However, the primary targets of H2 in the signal transduction pathways are unknown. ...

New reaction scheme is suggested for the initiated nonbranched-chain addition of free radicals to the multiple bond of the molecular oxygen. The scheme includes the reaction competing with chain propagation reactions through a reactive free radical. The chain evolution stage in this scheme involves a few of free radicals, one of which (tetraoxyl) is relatively low-reactive and inhibits the chai...

The chemical dynamics to synthesize the 2,4-pentadiynyl-1 radical, HCCCCCH(2)(X(2)B(1)), via the neutral-neutral reaction of dicarbon with methylacetylene, was examined in a crossed molecular beams experiment at a collision energy of 37.6 kJ mol(-1). The laboratory angular distribution and time-of-flight spectra of the 2,4-pentadiynyl-1 radical and its fragmentation patterns were recorded at m/...

Mn(III)-based oxidative free-radical cyclization of an unsaturated beta-keto ester containing a pyridine ring as radical trap has been studied. This intramolecular reaction of nucleophilic carbon-centered radicals with the pyridine ring leads to the stereospecific construction of a tetracyclic compound in which five chiral centers are created in one pot. This synthetic approach represents the f...

The intermolecular thiol-ene reaction is emerging as a highly efficient; free-radical mediated "click" process with diverse applications in biofunctionalisation and materials science. The related intramolecular thiol-ene reactions offer significant potential for the preparation of a wide range of sulphur containing heterocycles including synthetic therapeutics such as cyclic peptides and thiosu...

In the presence of PMe3 or N-heterocyclic carbenes, the reaction of oligosilanylene dianions with GeCl2⋅dioxane gives germylene-base adducts. After base abstraction, the free germylenes can dimerize by formation of a digermene. An electrochemical and theoretical study of a bicyclic tetrasilylated digermene revealed formation of a comparably stable radical anion and a more reactive radical catio...

The 13C enrichment observed in the first order photolytic decomposition of dibenzylketone (1,3-diphenyl2-propanone) was studied as a function of solvent viscosity and temperature. The isotope effect is due to electron-nuclear hyperfine interactions in the free radical intermediates of the reaction. The results are explained using a continuum diffusion model and a simplified version of the radic...

Antioxidants are vital substances which possess the ability to protect the body from damage caused by free radical induced oxidative stress. A variety of free radical scavenging antioxidants exist within the body which many of them are derived from dietary sources like fruits, vegetables and teas. In this study the antioxidant activity and radical scavenging activity of methanolic extracts of s...

the individual effects of cadmium concentrations (0, 0.005, 0.05and 0.5 mg. l-1) on the growth(cell number and chlorophyll content) and beta-carotene synthesis of two strains (iranian and australian) ofgreen algae d.salina have been studied for a duration of 36 days. the effects of these cadmiumconcentrations on the amount of cell magnesium and calcium have also been evaluated. an increase inca...

polymerization of styrene in presence of two monofunctional initiators is studied kinetically in an ampoule scale. polymerizations were ceased at different conversions for each ampoule while the temperature was increased almost linearly during the reaction. three different initiator mixtures were used. the first mixtures were composed of benzoil peroxide (bpo) and t-butyl perbenzoate (tbpb) wit...