Dihydroxamic Acids Research Articles

COPPER(II), NICKEL(II) AND ZINC(II) COORDINATION BY DIHYDROXAMIC ACIDS

Abstract Potentiometric titrations, absorption and e.p.r. spectra were used to establish coordination equilibria in Cu(II), Ni(II) and Zn(II) solutions with tetramethylenodihydroxamic acid and hexamethyleno-N,N′-diethylodihydroxamic acid. Results have shown that in all systems the major complexes formed at basic pH are dinuclear species. The complexes formed by dihydroxamic acids were found to be distinctly more stable than those of monohydroxamic acids.

Cystine dihydroxamic acid as a chelating agent

The copper(II), nickel(II) and zinc(II) complexes of cystine dihydroxamic acid [(Cys) 2dha] were studied by pH-metric and spectrophotometric methods. Planar complexes with 4N coordination were found with copper(II) and nickel(II) in the pH range ca 5.5–8.5. [M 2A 2] stoichiometry was supported by molecular mechanics calculations, using the MMX version of the MM2 force field method.

Preparation, characterization and M�ssbauer spectra of the iron(III) complexes of some dihydroxamic acids and amino monohydroxamic acids

FeIII complexes have been prepared from the dihydroxamic acids (CH2)n[CON(R)OH]2 (n=2, 3, 4, 6, 8; R=H, Ph,o-tolyl,p-tolyl) (H2L) and the amino monohydroxamic acids H2NCH(R)CONHOH (R=H, Me) (HL′) and XC6H4CONHOH (X=o-NH2,p-NH2) (HL″). Based on elemental analyses, molecular weight data, and electronic and i.r. spectra, the complexes have been formulated as Fe2(LH)2L2, Fe2L2O and Fe2L3 for the dihydroxamic acids, and Fe(OH)4L′2(H2O)2 and FeL″3 for the amino monohydroxamic acids. The57Fe Mossbauer spectra are discussed.

A simple field test for the detection of mercury in polluted water, air and soil samples

A simple field test for the detection of mercury is described. The test is based on the ligand exchange reaction where hexacyanoferrate(III) exchanges its cyanide ions with chromogenic organic ligand succinyl dihydroxamic acid (SDHA). In the reaction the colourless SDHA reacts with yellow K3Fe(CN)6 to give a greenish blue coloured complex in a slightly acidic solution containing mercury. The reaction has been successfully applied for the detection of mercury in polluted water, air and soil samples. In air, at a velocity of ∼0.21/min of the impinging air and a reaction temperature of ∼70°C, mercury(II) as low as 0.01 μg could be easily detected after 3 min exposure. In water the limit of identification and limit of dilution were found to be 0.2 μg Hg(II) and 1:200000, respectively.

The design of magnetic resonance contrast agents: New iron (III) dihydroxamate complexes

We have prepared a series of dihydroxamates and their iron (III) complexes in view of obtaining new NMR imaging agents. Four new dihydroxamic acid ligands have been synthesized by condensation of 4-substituted-2,6-pyridine dicarboxylic acids with N-aminopropyl-N-acetylhydroxylamine, and the iron (III) complexes exhibit high stability over the pH range 3 to 7 and a binuclear structure Fe 2L 3 at pH 7. The presence of two non-interacting paramagnetic centers per mole should allow a good compromise between an efficient relaxivity and limited toxicity.

N-hydroxy amides. Part 8. Synthesis and iron(III)-holding properties of di- and tri-hydroxamic acids extending from benzene-di- and -tri-carbonyl units through oligo(ethyleneoxy) arms

Benzene-ring centred di- and tri-hydroxamic acids (9a–c and 10a–c) having oligo(ethyleneoxy) chains are prepared by reaction of benzene-di- and -tri-carbonyl chlorides with amino [oligo(ethyleneoxy]ethyl hydroxylamine derivatives (6a–c). Trihydroxamic acids (10a–c) form more stable iron(III) complexes than dihydroxamic acids (9a–c) in several respects. In iron(III) transport experiments using a H2O–CHCl3/CCl4 system, however, compounds (9a–c) show greater rates than compounds (10a–c). The number of ethyleneoxy units in the arm apparently influences these iron(III) holding properties and the iron-transport rates.

ChemInform Abstract: Ferric Ion Sequestering Agents. Part 18. Two Dihydroxamic Acid Derivatives of EDTA and DTPA.

AbstractThe dihydroxamate anlogues (III) of the siderophore aerobactin, derived from EDTA and DTPA, are prepared from the corresponding dianhydrides (I) according to the scheme.

Ferric ion sequestering agents. 18. Two dihydroxamic acid derivatives of EDTA and DTPA

Preparation de 2 nouveaux analogues dihydroxamate de l'aerobactine, derives de l'EDTA et du DTPA. Determination des constantes de protonation et de stabilite des complexes de Fe(III)

ChemInform Abstract: Preparation of Some Dihydroxamic Acids and Their Reaction with Benzenesulfonyl Chloride.

AbstractThe hydroxamic acid derivatives (III) react with the chloride (IV) in the presence of base to give the derivatives (V).

ChemInform Abstract: Design of Metal Chelates with Biological Activity. Part 5. Complexation Behavior of Dihydroxamic Acids with Metal Ions.

AbstractThe dihydroxamic acids (III) are prepared as shown and characterized by analytical, NMR, and IR spectroscopic data.

ChemInform Abstract: Coordination Chemistry of Microbial Iron Transport. Part 37. Preparation, Structure, and Physical Properties of Dimeric Copper(II) Hydroxamate Complexes, Cu2L2 (L: iPrN(O)C(=O)(CH2)nC(=O)N(O)‐iPr, n = 3‐10).

AbstractThe title complexes are prepared in 90‐96% yield by 1:1 molar reaction of Cu(II) nitrate with a slight excess of dihydroxamic acid in methanol at pH 7‐8. These Cu complexes are dimeric for n = 5‐8, 10 and dissolve in a variety of polar organic solvents.

Design of metal chelates with biological activity. 5. Complexation behavior of dihydroxamic acids with metal ions

Etude par spectrometrie RMN des complexes Fe 2 L 3 , avec L=acides pimelohydroxamique et glutarodihydroxamique. Constantes de stabilite

Synthesis of dihydroxamic acid chelating polymers and the adsorptive property for uranium in sea water

AbstractPreparation of new chelating polymers bearing dihydroxamic acid groups and the adsorptive ability for uranium in sea water are described. Chloromethylated polystyrene crosslinked with divinylbenzene was treated with diethyl malonate in N, N‐dimethylformamide to give the polymer having diethyl malonate groups. This polymer was then treated with hydroxylamine in methanol to afford the dihydroxamic acid polymer. The presence of hydroxamic acid groups was confirmed by the appearance of IR absorption band at 1680 cm−1. The dihydroxamic acid polymer contained carboxylic acid groups as well as hydroxamic acid ones, and the contents of carboxylic acid and hydroxamic acid groups were estimated from elemental analysis to be 2–3 and 2–4 mmol/g, respectively. The polymer showed the adsorptive ability of 40 μg‐U/g in 8 days for uranium in sea water. In addition, the polymer showed the selective adsorptivity for iron, nickel, copper, and zinc as well as uranium. The macroreticular‐type polymer showed much higher adsorption rate for uranium in sea water than the gel‐type ones did, suggesting that the rate depends on the diffusion of the uranium in the polymer support.

ChemInform Abstract: A Facile Synthesis of Aliphatic Dihydroxamic Acids of General Formula RONR′‐CO‐(CH2)n‐CO‐NR′OR.

AbstractDie Bis‐hydroxamsäuren (IV) werden über die Diimidazolide (III), die aus den entsprechenden Dicarbonsäuren (I) durch Umsetzung mit N,N′‐Carbonyldiimidazol (II) leicht zugänglich sind, durch Reaktion mit Hydroxylamin in guten Ausbeuten hergestellt.

A Facile Synthesis of Aliphatic Dihydroxamic Acids of General Formula RONR'-CO-(CH2)n-CO-NR'OR

Abstract Synthesis of dihydroxamic acids using dicarboxylic acids and N.N'-carbonyldiimidazole.

Synthesis of some dihydroxamic acid siderophores

Synthese des acides (CH 2 ) n (CON(R)OH) 2 (n=2,3,4,6,8) par condensation de dichlorures d'acyle avec des N-arylhydroxylamines

The structure of the fungal siderophore, isotriornicin

A siderophore isolated from Epicoccus purpurascens has been found to be an isomer of triornicin (I) which differs from I only in interchange of the positions of acetyl and (E)-5-hydroxy-3-methyl-2-pentenoyl hydroxamate groups. The structure of the new compound, isotriornicin (II), was determined by spectroscopic techniques and by cleavage with methanol-ammonia to a new dihydroxamic acid (III) and N-acetyl- trans -fusarinine methyl ester (IV).

Identification of coprogen B and its breakdown products from Histoplasma capsulatum.

Iron added to a chemically defined liquid medium suppressed hydroxamic acid production at 37 degrees C by yeast cells of Histoplasma capsulatum. Four hydroxamic acids, HA-I, HA-II, HA-III, and HA-IV, present in the low-iron fluid after the culture of H. capsulatum were isolated by extraction and cation-exchange chromatography through cellulose phosphate (0.35% formic acid). Visible spectra of prepared ferrihydroxamates indicated that HA-II and HA-III were monohydroxamates, whereas HA-I and HA-IV were identified as di- and trihydroxamates, respectively. Reductive hydrolysis of HA-I (the major hydroxamic acid isolated) yielded ornithine. Hydrolysis of HA-IV in water or in 0.1 N NaOH resulted in the formation of HA-I (dihydroxamic acid) and HA-II (monohydroxamic acid). Based on their charge at pH 5.2 and 2 determined by paper electrophoresis, Rf values on thin-layer chromatography, infrared spectra, and reactivity to ninhydrin, three of the isolated hydroxamic acids were identified as deferricoprogen B (HA-IV) and its breakdown products, dimerumic acid (HA-I) and trans fusarinine (HA-II). HA-I and HA-IV exhibited growth factor activity for both yeast and mycelial forms of growth of H. capsulatum.

ChemInform Abstract: HYDROXAMIC ACIDS. VI. THE SYNTHESIS, PROPERTIES AND REACTIONS OF AMIDIC HYDROXAMIC ACID AND DIHYDROXAMIC ACID DERIVATIVES

AbstractDurch Reaktion entsprechender N‐Benzyloxyimide oder N‐Benzyloxyisoimide mit einem Äquivalent Benzylamin wurden die Hydroxamsäurederivate (Ia) bis (IIIa) erhalten.

Hydroxamic acids: VI. The synthesis, properties and reactions of amidic hydroxamic acid and dihydroxamic acid derivatives

Amidic hydroxamic acid and dihydroxamic acid derivatives of maleic, phthalic, fumaric and succinic acids have been prepared and their properties and reactions studied. In particular suitably oriented derivatives of these systems have been investigated to ascertain whether they are capable of existing in, or reacting through, various cyclol tautomers. Attempts to trap the cyclol tautomers are described and these results, together with other indirect chemical evidence as well as the spectral data, suggest that the cyclol tautomer may be present in some cases, in contrast to the corresponding diamides which do not show similar behaviour.