Triferric

The title compound, tricaesium sodium iron(III) μ3-oxido-hexa-μ2-sulfato-tris[aquairon(III)] pentahydrate, Cs2.91Na1.34Fe(3+)0.25[Fe3O(SO4)6(H2O)3]·5H2O, belongs to the family of Maus's salts, K5[Fe3O(SO4)6(H2O)3]·6H2O, which is based on the triaqua-μ3-oxido-hexa-μ-sulfato-triferrate(III) anion, [Fe3O(SO4)6(H2O)3](5-), with Fe in a characteristically distorted octahedral coordination environment, sharing a common corner via an oxide O atom. Cs in four different cation sites, Na in three different cation sites and five water molecules link the anions in three dimensions and set up a crystal structure in which those parts parallel to (001) and within 0...

Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; little is known about other ferric citrate-binding proteins. Here we report a unique siderophore-binding protein from the gram-positive pathogenic bacterium Bacillus cereus that binds multinuclear ferric citrate complexes. We have demonstrated that B. cereus ATCC 14579 takes up (55)Fe radiolabeled ferric citrate and that a protein, BC_3466 [renamed FctC (ferric citrate-binding protein C)], binds ferric citrate...

The title compound, dipotassium diaqua-bis-(diphosphato)triferrate(II), K(2)[Fe(II) (3)(P(2)O(7))(2)(H(2)O)(2)], was synthesized under solvothermal conditions. The crystal structure is isotypic with its Co analogue. In the structure, there are two crystallographically distinct Fe positions; one lies on an inversion center, the other on a general position. The first Fe(2+) cation adopts a regular octa-hedral coordination with six O atoms, whereas the other is coordinated by five O atoms and a water mol-ecule...

Diammonium diaquabis(phosphato)triferrate(II), (NH(4))(2)[Fe(3)(P(2)O(7))(2)(H(2)O)(2)], was synthesized under solvo-thermal conditions at 463 K. The crystal structure, isotypic to its Mn and Ni analogues, is built from iron pyrophosphate layers parallel to (100), which are linked by ammonium ions sitting in the inter-layer space via O-H⋯O and N-H⋯O hydrogen bonds. There are two crystallographic Fe sites in the crystal structure, one at a special position (2a, [Formula: see text]), the other at a general position (4e, 1)...

The title compound, (C(6)H(16)N)[Fe(3)(CH(3)CO(2))(8)O(H(2)O)]·C(7)H(8), was serendipitously crystallized from a reaction of disilanol with iron(II) acetate. The trinuclear acetatoferrate(III) anion has a triethyl-ammonium cation as the counterion. The three Fe atoms lie on the vertices of a regular triangle and are octa-hedrally coordinated. The complete coordination of the anion includes shared ligands among the three metal ions: a central tribridging O atom and six bidentate bridging acetyl groups. The six-coordinations of two of the metal ions are completed by a monodentate acetate ligand, whereas that of the third metal ion is completed by a water mol-ecule...

Five sensitive, selective and precise stability-indicating methods are presented for the determination of famciclovir (FCV) in the presence of its alkaline-induced degradation product. Method A utilizes the first derivative spectrophotometry at 321 nm. Method B depends on using the first derivative of the ratio spectrophotometry (DD(1)) by measurement of the amplitude at 256 nm. Method C is based on the reaction of FCV with hydroxylamine to form hydroxamic acid, causing the hydroxamic acid to react with triferric ion to form ferric hydroxamate that is measured at 503 nm...

The title compound, tetraethylammonium dodeca-mu-cyano-hexacyanotetrakis(ethylenediamine)tetracadmium(II)triferrate(III), (C(8)H(20)N)[Cd(4)Fe(3)(CN)(18)(C(2)H(8)N(2))(4)], was prepared from a reaction mixture containing CdCl(2), K(3)[Fe(CN)(6)], ethylenediamine (en) and [Et(4)N]Br in a 1:1:3:1 molar ratio. The crystal structure consists of a negatively charged three-dimensional framework of [[Cd(en)](4)[Fe(CN)(6)](3]n)(n-) anions, with [Et(4)N](+) cations located in the cavities of the framework. The Cd atom is octahedrally coordinated by one disordered chelating en molecule [mean Cd-N = 2...

Reaction of alpha-P(2)W(15)O(56)(12-) and Fe(III) in a saturated NaCl solution produces a trisubstituted Wells-Dawson structure with three low-valent metals, alpha-(Fe(III)Cl)(2)(Fe(III)OH(2))P(2)W(15)O(59)(11-) (1). Dissolution of this species into 1 M NaBr (Br(-) is non-coordinating) gives the triaquated species alpha-(Fe(III)OH(2))(3)P(2)W(15)O(59)(9-) (2). Ionic strength values of 1 M or greater are necessary to avoid decomposition of 1 or 2 to the conventional sandwich-type complex, alpha beta beta alpha-(Fe(III)OH(2))(2)Fe(III)(2)(P(2)W(15)O(56))(2)(12-) (3)...

The monoliganded and triliganded forms of the asymmetric valency hybrids of carp hemoglobin were isolated using high-performance liquid chromatography. These partially oxidized hybrids were shown to be sufficiently stable to permit the measurement of the kinetics of CO binding. The effects of protons and inositol hexaphosphate on the rates of these reactions were examined. The kinetics of CO recombination with these partially oxidized derivatives were compared to the kinetics of CO binding to the fully ferrous molecule...

Quelamycin is triferric doxorubicin, a metallic derivative of adriamycin which, in experimental studies, has been found to have a better therapeutic index than adriamycin and no cardiotoxicity. In Spain, phase I clinical trials carried out in 96 patients with advanced cancer have shown that the drug has low toxicity and considerable antitumor activity, while it is not cardiotoxic, even at cumulative doses of nearly 3 g.

Fe(III) complexes of two anthracyclines, adriamycin and daunorubicin, have been studied. Using potentiometric and spectroscopic measurements, we have shown that adriamycin and daunorubicin form two well-defined species with Fe(III), which can be formulated as respectively Fe(HAd)3 and Fe(HDr)3. In these formulas, HAd and HDr stand for adriamycin and daunorubicin in which the 1,4-dihydroxy-anthraquinone moiety is half-deprotonated. Both complexes are six-membered chelates. The stability constant is beta = (2...

Hemoglobin A, cross-linked between Lys 99 alpha 1 and Lys 99 alpha 2, was used to obtain a partially oxidized tetramer in which only one of the four hemes remains reduced. Because of the absence of dimerization, asymmetric, partially oxidized derivatives are stable. This is evidenced by the fact that eight of the ten possible oxidation states could be resolved by analytical isoelectric focusing. A triply oxidized hemoglobin population HbXL+3 was isolated whose predominant component was (alpha + alpha +, beta + beta 0)...

The electrophilic properties of the quinone-hydroquinone configuration of anthracycline antibiotics suggests a possible influence on cytochrome P-450-mediated mono-oxygenase reactions. Both doxorubicin and triferric-doxorubicin (a derivative in which the quinone groups are blocked with iron) showed a similar dose-dependent inhibition of liver microsomal drug metabolism. A doxorubicin concentration-related stimulation of NADPH oxidase activity was found to be linear but that for triferric-doxorubicin was asymptotic...

Quelamycin (triferric doxorubicin) is a derivative of Adriamycin with different pharmacologic properties. Our phase I clinical study of quelamycin includes 37 patients with a wide spectrum of solid tumors. The recommended dose in good-risk patients is 150 mg/m2, given as a 1-hour infusion every 3 weeks. The dose-limiting factor appears to be myelosuppression, especially leukopenia. Other toxic effects include gastrointestinal intolerance and alopecia. Chills and fever are commonly encountered and might be due to an excess of free iron in currently available preparations...

A phase I clinical study was done with quelamycin, a recently synthesized triferric derivative of adriamycin. Twenty-one good-risk patients were studied: 19 patients with non-small cell carcinoma of the lung and two patients with metastatic sarcoma. Acute toxicity occurred in all patients and consisted of high fever, flushing, hypertension, generalized body aches, tremors, and confusion, which lasted 3-6 hours. Potentially dangerous cardiotoxicity occurred in eight patients who had previous minor rhythm disturbances, and was characterized by tachycardia, atrial extrasystoles, atrial fibrillation, and branch block which lasted 6-14 hours...