Janice L. Wong, Robert F. Higgins, Indrani Bhowmick, David Xi Cao, Géza Szigethy, Joseph W. Ziller, Matthew P. Shores* and Alan F. Heyduk* A new bimetallic platform comprising a six-coordinate Fe(ONO)2 unit bound to an (ONO)M (M1⁄4 Fe, Zn) has been discovered ((ONO)H3 1⁄4 bis(3,5-di-tert-butyl-2-phenol)amine). Reaction of Fe(ONO)2 with either (ONO)Fe(py)3 or with (ONO )FeCl2 under reducing cond...

Superoxide reductases (SORs) are nonheme iron-containing enzymes that reduce HO(2) to H(2)O(2). Exogenous substrates such as N(3)(-) and CN(-) have been shown to bind to the catalytic iron site of SOR, and cyanide acts as an inhibitor. To understand how these exogenous ligands alter the physical and reactivity properties of the SOR iron site, acetate-, azide-, and cyanide-ligated synthetic mode...

a number of 6-hydroxy-2-benzylidene-3-coumaranones were synthesized from condensation of 6-hydroxy-3-coumaranone with appropriate aldehydes and were evaluated for their antioxidant activities. the antioxidant activity was assessed using two methods, including, 1,1-biphenyl-2-picrylhydrazyl (dpph) radical scavenging, and reducing power assays. some of the benzylidene coumaranones showed antioxid...

Detailed hydrochemical measurements, SSO4 and H analyses were performed on 37 groundwater samples collected during February 1999, January and March 2000 from 6 locations in eastern and southeastern Bangladesh to examine redox processes that lead to As mobilization in groundwater. The study sites were chosen based on available nation-wide As surveys to span the entire spectrum of As concentratio...

Originally discovered in the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 (MR-1), key components of the Mtr (i.e. metal-reducing) pathway exist in all strains of metal-reducing Shewanella characterized. The protein components identified to date for the Mtr pathway of MR-1 include four multihaem c-Cyts (c-type cytochromes), CymA, MtrA, MtrC and OmcA, and a porin-like outer m...

Archaeoglobus fulgidus, a hyperthermophilic sulfate-reducing Archaeon, contains high Fe(3+)-EDTA reductase activity in its soluble protein fraction. The corresponding enzyme, which constitutes about 0.75% of the soluble protein, was purified 175-fold to homogeneity. Based on SDS-polyacrylamide gel electrophoresis, the ferric reductase consists of a single subunit with a M(r) of 18,000. The M(r)...

This work describes an easy synthesis (one pot) of MFe(2)O(4) (M = Co, Fe, Mn, and Ni) magnetic nanoparticles MNPs by the thermal decomposition of Fe(Acac)(3)/M(Acac)(2) by using BMI·NTf(2) (1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) or BMI·PF(6) (1-n-butyl-3-methylimidazolium hexafluorophosphate) ionic liquids (ILs) as recycling solvents and oleylamine as the reducing and...

The aim of this research was to synthesize and develop a new method for the preparation of iron oxide (Fe(3)O(4)) nanoparticles on talc layers using an environmentally friendly process. The Fe(3)O(4) magnetic nanoparticles were synthesized using the chemical co-precipitation method on the exterior surface layer of talc mineral as a solid substrate. Ferric chloride, ferrous chloride, and sodium ...

The dissimilatory Fe(III)-reducing bacterium Geobacter sulfurreducens reduced and precipitated Tc(VII) by two mechanisms. Washed cell suspensions coupled the oxidation of hydrogen to enzymatic reduction of Tc(VII) to Tc(IV), leading to the precipitation of TcO(2) at the periphery of the cell. An indirect, Fe(II)-mediated mechanism was also identified. Acetate, although not utilized efficiently ...