PURPOSE The aim of this study was to evaluate antioxidant ability of mangosteen shell and explore the non-enzymatic repair reaction and possible mechanism of xanthones in mangosteen shell. METHODS Mangosteen shell was extracted by methanol to obtain the extract of mangosteen shell. The extract was then determined by various antioxidant assays in vitro, including protection against DNA damage,...

Ordered mesoporous Fe(3)O(4) with crystalline walls (inverse spinel structure) has been synthesized for the first time, representing to the best of our knowledge, the first synthesis of a reduced mesoporous iron oxide. Synthesis was achieved by reducing ordered mesoporous alpha-Fe(2)O(3) (corundum structure) to Fe(3)O(4) spinel then to gamma-Fe(2)O(3) by oxidation, while preserving the ordered ...

Nd-Fe-B/α-Fe multi-layered nanocomposite film-magnets were prepared from a rotating Nd2.6Fe14B/α-Fe composite target by the pulse laser deposition method with a NdYAG laser (λ=355 nm). The prepared film-magnets were composed of approximately 800 layers with the thickness of about several tens nanometre, and exhibited hard magnetic properties after annealing. The laser power for the ablation of ...

-The role of adsorbed and structural Fe n+ in palygorskite and sepiolite with respect to the oxidation of hydrocortisone in aqueous suspension has been evaluated using electron spin resonance and UVvisible spectroscopy. Natural surface-adsorbed Fe 3+ showed an important activity in the oxidation process, although smaller than octahedral Fe 3+. The kinetics of oxidative degradation of hydrocorti...

objective: the present study was an attempt to study total phenolic content and antioxidant property of the crude ethanolic extract of the roots of azadirachta indica (a. indica). materials and methods: to evaluate the antioxidant properties of the crude extract, some complementary test systems, namely dpph free radical scavenging assay, reducing power assay, and ferrous ion chelating ability a...

Ectomycorrhizal fungi play a key role in mobilizing nutrients embedded in recalcitrant organic matter complexes, thereby increasing nutrient accessibility to the host plant. Recent studies have shown that during the assimilation of nutrients, the ectomycorrhizal fungus Paxillus involutus decomposes organic matter using an oxidative mechanism involving Fenton chemistry (Fe(2+) + H2O2 + H(+) → Fe...

At an initial pH of 2, while abiotic oxidation of aqueous Fe(2+) was enhanced by a flux of H2O2 at micromolar concentrations, bio-oxidation of aqueous Fe(2+) could be impeded due to oxidative stress/damage in Acidithiobacillus ferrooxidans caused by Fenton reaction-derived hydroxyl radical, particularly when the molar ratio of Fe(2+) to H2O2 was low. When pyrite cubes were intermittently expose...

Twenty one of 118 irrigation water wells in the shallow (25-30 m thick) Mississippi River Valley alluvial aquifer in the Bayou Bartholomew watershed, southeastern Arkansas had arsenic (As) concentrations (<0.5 to 77 microg/L) exceeding 10 microg/L. Sediment and groundwater samples were collected and analyzed from the sites of the highest, median, and lowest concentrations of As in groundwater i...

Dissimilatory Fe(III) reduction is a universal process with irreplaceable biological and environmental importance in anoxic environments. Our knowledge about Fe(III) reduction predominantly comes from pure cultures of dissimilatory Fe(III) reducing bacteria (DFRB). The objective of this study was to compare the effects of glucose and a selection of short organic acids (citrate, succinate, pyruv...

The DNA cleavage activity of iron(II) complexes of a series of monotopic pentadentate N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine (N4Py)-derived ligands (1-5) was investigated under laser irradiation at 473, 400.8, and 355 nm in the absence of a reducing agent and compared to that under ambient lighting. A significant increase in activity was observed under laser irradiation, which is ...