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PubMed1990

Determination of hydrazine in hydralazine by capillary gas chromatography with nitrogen-selective detection after benzaldehyde derivatization.

A method for the determination of hydralazine substance is described. Hydrazine is derivatized in aqueous media with benzaldehyde to benzalazine. After extraction to an organic phase containing a homologue as marker, the sample is subjected to capillary column gas chromatography with nitrogen-selective detection. A prolonged reaction with 0.1 M benzaldehyde of 20 min or more led to an increased level of benzalazine when hydralazine was analysed. An increase was also observed if the aqueous hydralazine sample had been allowed to stand for some time before analysis. The final method involved the use of a 5-min reaction time, fresh solutions and the standard addition principle. The levels of hydrazine found in hydralazine hydrochloride were below 1 ppm (as bases, 1 ng/mg).

Benzaldehydes↗
PubMed2002

Key factors in chemical reduction by hydrazine for recovery of precious metals.

Most of the commonly used metal waste treatment approaches only allow removal of metals which are ultimately discarded as sludge and do not permit the reuse of the metals, resulting in a waste of raw materials. In this study, the recovery of precious metals of sliver and copper in a synthesized wastewater in batch reactors was investigated using a reduction method by hydrazine as the reducing agent. Recovery of metal ions was greatest at pH > 11. The presence of humic acid did not have negative effects on the recovery process. Varying dissolved oxygen levels in the hydrazine solution did not significantly affect the recovery of both metals while seeding and ageing processes resulted in an increase in the particle size of the solid obtained. Under competitive conditions between Cu2+ and Ag+ ions, the recovery of silver remained the same, while that of copper was enhanced.

Copper↗
PubMed2001

The metabolism and bioactivation of agaritine and of other mushroom hydrazines by whole mushroom homogenate and by mushroom tyrosinase.

Whole homogenates of Agaricus bisporus metabolised the mushroom hydrazine agaritine [beta-N-(gamma-L(+)glutamyl)-4-(hydroxymethyl) phenylhydrazine] to generate at least three metabolites. None of these metabolites, however, was the free hydrazine [4-(hydroxymethyl)phenylhydrazine], the postulated metabolite of agaritine believed to be formed as a result of the loss of the gamma-glutamyl group, the reaction being catalysed by gamma-glutamyltransferase. The three metabolites of agaritine displayed weak mutagenic activity towards Salmonella typhimurium strain TA104. 4-(Hydroxymethyl)phenylhydrazine, as the N'-acetyl derivative, was metabolised by mushroom tyrosinase to yield a number of metabolites that induced a mutagenic response in S. typhimurium TA104. Similar to N'-acetyl-4-(hydroxymethyl)phenylhydrazine, agaritine was extensively metabolised by the mushroom tyrosinase but, in contrast, the structurally related N'-acetyl-4-hydrazinobenzoic acid did not serve as substrate of this enzyme, implying a critical role for the hydroxymethyl group at the para-position. In conclusion, the current studies have demonstrated for the first time that: (a) whole mushroom homogenates readily metabolise agaritine but not to the postulated 4-(hydroxymethyl)phenylhydrazine; and (b) mushroom tyrosinase metabolises agaritine and N'-acetyl-4-(hydroxymethyl)phenylhydrazine, in the latter case forming genotoxic metabolites.

Agaricales↗
PubMed1998

Organ-specific genotoxicity of the potent rodent colon carcinogen 1,2-dimethylhydrazine and three hydrazine derivatives: difference between intraperitoneal and oral administration.

We used a modification of the alkaline single cell gel electrophoresis (SCG) (Comet) assay to test the in vivo genotoxicity of four hydrazine derivatives--1,2-dimethylhydrazine (SDMH), 1,1-dimethylhydrazine (UDMH), hydrazine (HZ), and procarbazine (PCZ)--in mouse liver, lung, kidney, brain, and bone marrow, and in the mucosa of stomach, colon, and bladder. Mice were sacrificed 3 and 24 h after intra-peritoneal (i.p.) and oral (p.o.) administration. SDMH at 20 mg/kg i.p. yielded statistically significant DNA damage in all tested organs except for lung. In the gastrointestinal tract, SDMH was genotoxic in the stomach and the colon after i.p. treatment but only in the colon after 20 and 30 mg/kg p.o. treatment. UDMH at 50 mg/kg i.p. yielded DNA damage in the liver and lung at 3 h. PCZ at 200 mg/kg i.p. caused DNA damage in the liver, kidney, lung, brain, and bone marrow. UDMH and PCZ were positive in the stomach and colon p.o. but not by i.p. treatment. HZ at 100 mg/kg yielded DNA damage in the stomach, liver, and lung when given i.p. and in the brain when p.o. Thus, the administration route is important when evaluating organ-specific genotoxicity in multiple organs.

1,2-Dimethylhydrazine↗
PubMed1993

Ion mobility spectrometry of hydrazine, monomethylhydrazine, and ammonia in air with 5-nonanone reagent gas.

Hydrazine (HZ) and monomethylhydrazine (MMH) in air were monitored continuously using a hand-held ion mobility spectrometer equipped with membrane inlet, 63Ni ion source, acetone reagent gas, and ambient temperature drift tube. Response characteristics included detection limit, 6 ppb; linear range, 10-600 ppb; saturated response, >2 ppm; and stable response after 15-30 min. Ammonia interfered in hydrazines detection through a product ion with the same drift time as that for MMH and HZ. Acetone reagent gas was replaced with 5-nonanone to alter drift times of product ions and separate ammonia from MMH and HZ. Patterns in mobility spectra, ion identifications from mass spectra, and fragmentation cross-sections from collisional-induced dissociations suggest that drift times are governed by ion-cluster equilibria in the drift region of the mobility spectrometer. Practical aspects including calibration, stability, and reproducibility are reported from the use of a hand-held mobility spectrometer on the space shuttle Atlantis during mission STS-37.

Ammonia↗
PubMed1992

Active site structure of methylamine dehydrogenase: hydrazines identify C6 as the reactive site of the tryptophan-derived quinone cofactor.

To identify the reactive part of the orthoquinone function of the tryptophan-derived cofactor found in methylamine dehydrogenase (MADH), we have determined the crystal structures of MADH from Thiobacillus versutus inhibited by methylhydrazine and (2,2,2-trifluoroethyl)hydrazine. Extra electron density attached to C6 of the tryptophyl tryptophanquinone cofactor shows that this atom and not C7 is the reactive part of the ortho-quinone moiety. The density retained after hydrazine inhibition is much less extensive than expected, however, suggesting that partial breakdown of the inhibitors after reaction with the cofactor may take place. A detailed description is presented of the cofactor environment in an improved model of MADH which now includes information from the recently determined gene sequence of the cofactor-containing subunit [Ubbink, M., van Kleef, M.A.G., Kleinjan, D., Hoitink, C.W.G., Huitema, F., Beintema, J.J., Duine, J.A., & Canters, G.W. (1991) Eur. J. Biochem. 202, 1003-1012]. We hypothesize that Asp76 is responsible for proton abstraction from the alpha-carbon of the substrate during catalysis.

Amino Acid Sequence↗
PubMed2006

Hydrazine nitrosation of a metal-bound nitric oxide: structural evidence for the formation of an ammine complex.

Hydrazine nitrosation of [Ru(NO)(py(si)S4)]Br.THF (1) (py(si)S4(2-) = 2,6-bis(3-triphenylsilyl-2-sulfanylphenylthiomethyl)pyridine2-) in methanol/DMF led to the formation of mononuclear ammine complex [Ru(NH3)(py(si)S4)] (2) and N2O, whereas the reaction performed in THF/CH2Cl2/toluene afforded thioether-bridged dinuclear ammine complex [(NH3)Ru(mu-py(si)S4)Ru(py(si)S4)] (3). Compound 2 dimerizes in solution at room temperature to form 3 and is regenerated upon treatment of 3 with NH3. A plausible mechanism for the hydrazine nitrosation of 1 has been proposed. The reaction of 1 with NH3 or N3- does not lead to a nucleophilic attack at the NO+ ligand but to a deprotonation that yields neutral nitrosyl complex [Ru(NO){py(si)S4(H+)}] (4), which is supported by density functional theory calculations.

Amines↗
PubMed2006

Catalytic reduction of hydrazine to ammonia by a vanadium thiolate complex.

Vanadium(III) thiolate complexes, [V(PS3'')(Cl)]- [1a; PS3'' = P(C6H3-3-Me3Si-2-S)3(3-)] and [V(PS3')(Cl)]- [1b; PS3' = P(C6H3-5-Me-2-S)3(3-)], were synthesized and characterized. Complex 1a serves as a precursor for the catalytic reduction of hydrazine to ammonia. The spectroscopic and electrochemical studies indicate that hydrazine is bound and activated in a V(II) state.

Ammonia↗
PubMed1986

Synthesis, structure, and antitumor activity of N-salicyloyl-N'-(2-furylthiocarbonyl)hydrazine and its copper(II) complex.

N-Salicyloyl-N'-(2-furylthiocarbonyl)hydrazine (H2sfth) and its Cu(II) complex [Cu(sfth)] were prepared and characterized by physicochemical studies. The IR and ESR spectral studies imply dibasic tetradentate behavior of the ligand bonding through "thiolo" sulfur, enolic oxygen, and hydrazinic nitrogens in a polymeric structure. The electronic spectrum of the complex indicates a square-planar geometry around Cu(II). Maximum antitumor activity was observed when 25 mg/kg dose levels of H2sfth and Cu(sfth) were injected intraperitoneally in mice bearing either solid fibrosarcoma or ascites Dalton's lymphoma. However, H2sfth appeared to possess better antitumor activity as demonstrated by higher T/C (percent) values than those observed for Cu(sfth). The appearance of lymphocytes, leukocytes, and macrophages within the tumor mass 2-6 days after treatment are indicative of involvement of the host's immune system.

Animals↗
PubMed1986

Synthesis and evaluation of 2-substituted 1-methyl-1-(4-tolylsulfonyl)hydrazines as antineoplastic agents.

Several N-2 substituted 1-methyl-1-(4-tolylsulfonyl)hydrazines were synthesized and evaluated for antineoplastic activity against the L1210 leukemia and the B16 melanoma. The most active compound to emerge from this study, 2-(methylsulfonyl)-1-methyl-1-(4-tolylsulfonyl)hydrazine, produced maximum percent T/C values with L1210 leukemia and B16 melanoma tumor bearing mice of 207 and 209, respectively. While the attachment of an aryl-, aralkyl-, or alkylsulfonyl moiety to N-2 resulted in retention of activity against both tumor systems, the corresponding benzoyl, 4-nitrobenzoyl, and (2-nitrophenyl)sulfenyl analogues only displayed activity against the L1210 leukemia.

Animals↗
PubMed2001

Temporary inactivation of plasma amine oxidase by alkylhydrazines. A combined enzyme/model study implicates cofactor reduction/reoxidation but cofactor deoxygenation and subsequent reoxygenation in the case of hydrazine itself.

It has been known for some time that hydrazine and its methyl and 1,1-dimethyl analogues induce inactivation of the copper-containing quinone-dependent plasma amine oxidase but that the activity recovers over time, suggesting metabolism of all three inhibitors. However, the mechanism responsible for loss and regain of activity has not been investigated. In this study a combination of enzyme studies under a controlled atmosphere along with model studies using 5-tert-butyl-2-hydroxy-1,4-benzoquinone to mimic the 2,4,5-trihydroxyphenylalanine quinone (TPQ) cofactor of the enzyme suggest that regain of enzyme activity represents two different O(2)-dependent processes. In the case of methylhydrazine and 1,1-dimethylhydrazine, we propose that the inactive methylhydrazone/azo form of the enzyme slowly rehydrates and eliminates MeN=NH to give the triol cofactor form, which instantly reoxidizes to the catalytically active quinone form in the presence of O(2). Metabolism of methylhydrazine represents its conversion to CH(4) and N(2), and of 1,1-dimethylhydrazine to CH(2)=O, CH(4), and N(2). In the case of hydrazine itself, however, we propose that the inactive hydrazone/azo form of the enzyme instead undergoes a slow decomposition, probably facilitated by the active-site copper, to give N(2) and a novel 5-desoxy resorcinol form of the cofactor. The latter undergoes a rapid, but noninstantaneous reoxygenation at C5 to restore the active cofactor form, also probably mediated by the active-site copper.

Amine Oxidase (Copper-Containing)↗
PubMed2006

Origin of rotational barriers of the N-N bond in hydrazine: NBO analysis.

Hydrazine passes through two transition states, TS1 (phi = 0 degrees ) and TS2 (phi = 180 degrees ), in the course of internal rotation around its N-N bond. The origin of the corresponding rotational barriers in hydrazine has been extensively studied by experimental and theoretical methods. Here, we used natural bond orbital (NBO) analysis and energy decomposition of rotational barrier energy (DeltaE(barrier)) to understand the origin of the torsional potential energy profile of this molecule. DeltaE(barrier) was dissected into structural (DeltaE(struc)), steric exchange (DeltaE(steric)), and hyperconjugative (DeltaE(deloc)) energy contributions. In both transition states, the major barrier-forming contribution is DeltaE(deloc). The TS2 barrier is lowered by pyramidalization of nitrogen atoms through lowering DeltaE(struc), not by N-N bond lengthening through lowering DeltaE(steric). Higher pyramidality of nitrogen atoms of TS2 than that of TS1 explains well why the N-N bond of TS2 is longer than that of TS1. Finally, the steric repulsion between nitrogen lone pairs does not determine the rotational barrier; nuclear-nuclear Coulombic repulsion between outer H/H atoms in TS1 plays an important role in increasing DeltaE(struc). Taken together, we explain the reason for the different TS1 and TS2 barriers. We show that NBO analysis is a useful tool for understanding structures and potential energy surfaces of compounds containing the N-N bond.

Electrons↗
PubMed1991

Air oxidation of hydrazine. 1. Reaction kinetics on natural kaolinites, halloysites, and model substituent layers with varying iron and titanium oxide and O- center contents.

Air oxidation of hydrazine was studied by using a group of kaolinites, halloysites, and substituent oxides as models for the tetrahedral and octahedral sheets. The rate was found to be linear with oxygen. The stoichiometry showed that oxygen was the primary oxidant and that dinitrogen was the only important nitrogen-containing product. The rates on kaolinites were strongly inhibited by water. Those on three-dimensional silica and gibbsite appeared not to be. That on a supposedly layered silica formed from a natural kaolinite by acid leaching showed transitional behavior--slowed relative to that expected from a second-order reaction relative to that on the gibbsite and silica but faster than those on the kaolinites. The most striking result of the reaction was the marked increase in the rate of reaction of a constant amount of hydrazine as the amount of clay was increased. The increase was apparent (in spite of the water inhibition at high conversions) over a 2 order of magnitude variation of the clay weight. The weight dependence was taken to indicate that the role of the clay is very important, that the number of reactive centers is very small, or that they may be deactivated over the course of the reaction. In contrast to the strong dependence on overall amount of clay, the variation of amounts of putative oxidizing centers, such as structural Fe(III), admixed TiO2 or Fe2O3, or O- centers, did not result in alteration of the rate commensurate with the degree of variation of the entity in question. Surface iron does play some role, however, as samples that were pretreated with a reducing agent were less active as catalysts than the parent material. These results were taken to indicate either that the various centers interact to such a degree that they cannot be considered independently or that the reaction might proceed by way of surface complexation, rather than single electron transfers.

Aluminum Silicates↗
PubMed1991

Surface activation of air oxidation of hydrazine on kaolinite. 2. Consideration of oxidizing/reducing entities in relationship to other compositional, structural, and energetic factors.

The rates (previously reported) for the air oxidation of hydrazine on kaolinite and substituent oxides of kaolinite showed a complex dependence on the relative amounts of several structural oxidizing/reducing entities within the reaction-promoting solids. The rates indicated an important role of the clay but no dominant role of any one of the oxidizing/reducing entities. In this paper we review (a) the reaction-promoting activity of these centers as studied in other systems, (b) various spectroscopic results showing interaction between these entities in clays, and (c) reported spectroscopic studies of the complexation between hydrazine and aluminosilicate surfaces as a whole, in an effort to propose a mechanism for the reaction. Whereas some uncertainties remain, the present synthesis concludes that a mechanism operating through single electron/hole transfers and hydrogen atom transfers by discrete centers is adequate to explain the observed rate behaviors including the observed second order dependence of the oxidation rate on catalyst amount. The effects of these operations on the catalyst can result in no alteration of, or complete or partial electronic relaxation of its contingent of trapped separated charge pairs. The degree to which surface complexation as a whole, intercalation, or luminescent processes may also be associated with the reaction cannot be adequately assessed with the information in hand.

Aluminum Silicates↗
PubMed2001

Asymmetric synthesis of alpha-branched primary amines on solid support via novel hydrazine resins.

[reaction: see text]. Two novel chiral hydrazine resins for asymmetric solid-phase synthesis have been developed. The enantiopure beta-methoxyamino auxiliaries, derived from trans-4-hydroxy-(S)-proline and (R)-leucine, were attached to Merrifield resin and transformed into their corresponding hydrazines. Immobilization of various aldehydes, followed by 1,2-addition of organolithium reagents to the resulting enantiopure hydrazones and reductive cleavage from the solid support, furnished alpha-branched amines, which were isolated as their corresponding amides in good overall yields and enantiomeric excesses of up to 86%.

Amines↗
PubMed2004

Trifluoroacetyl-activated nitrogen-nitrogen bond cleavage of hydrazines by samarium(II) iodide.

[reaction: see text] Trifluoroacetyl derivatives of hydrazines undergo clean and efficient reductive cleavage of the N-N bond with SmI(2) in the presence of MeOH. After N-trifluoroacetylation, acyl-, aryl-, and alkyl-substituted hydrazines are reductively cleaved by this method to afford trifluoroacetamides in yields ranging from 70 to 96%. These conditions accommodate alkene functionality, avoid racemization, and furnish chiral amines bearing a readily removable TFA protecting group.

Hydrazines↗
PubMed1971

A study of the formation of fluorescent derivatives of 4-hydroxyphenethylamine (tyramine), 4-hydroxy-3-methoxyphenethylamine (3-methoxytyramine) and related compounds by reaction with hydrazine in the presence of nitrous acid.

A reaction is described that allows the preparation of fluorescent derivatives of a group of related compounds with the basic 4-hydroxyphenethylamine structure. Examination of the reaction shows that it takes place in two stages, which can be considered separately. (1) Reaction of hydrazine with nitrous acid: this is instantaneous at room temperature and involves the reaction of 1 mol of hydrazine with 2 mol of nitrous acid. (2) Reaction with 4-hydroxyphenethylamine compounds: this occurs slowly at room temperature but the rate of reaction is significantly increased at higher temperatures. Ammonium sulphamate is added to remove excess of nitrous acid, found to be detrimental to the reaction. Examination of reagent concentrations necessary for maximum fluoresence yield demonstrated the need for a 40-fold molar excess of the reagent formed in the first stage. The derivatives fluoresce in alkaline solution, the fluorescence of derivatives of 4-hydroxy compounds being stable for over 1h at room temperature, those of 4-hydroxy-3-methoxy compounds being slightly less stable. The derivatives were distinguishable from their parent compounds by t.l.c.

Chemical Phenomena↗
PubMed2000

Functional aspects of megamitochondria isolated from hydrazine- and ethanol-treated rat livers.

It is essential to analyze functions of megamitochondria (MG) to elucidate the mechanism of the formation of MG induced under various pathological conditions. The MG fraction obtained by a routine isolation procedure for normal mitochondria always consists of a mixed population of mitochondria enlarged to various degrees and also normal-sized ones. The purpose of the present study is to answer the question of whether or not data obtained from the MG fraction consisting of such a heterogeneous population of mitochondria with respect to their sizes really reflect functions of MG. In the present study mitochondria were obtained from the livers of rats treated with a 1% hydrazine diet for 8 days and those given 32% ethanol in drinking water for up to 2 months using various isolation procedures. Results obtained are summarized as follows: (i) mitochondria enlarged to various degrees and normal-sized ones are sometimes connected with each other by a narrow stalk in the hepatocyte of hydrazine-treated animals, and such connections are maintained to some extent when mitochondria are isolated; and (ii) mitochondria obtained from experimental animals by a routine isolation procedure for mitochondria ((700-7000)gR2"') and those obtained by alternative isolation procedure yielding the heavy ((500-2000)gR2"') and light ((2000-7000)gR2"') fractions show some functional similarities: decreases in the content of cytochrome a + a3; decreases in oxygen consumptions and phosphorylating abilities; decreases in monoamine oxidase and cytochrome c oxidase activities; lowered membrane potential of mitochondria; decreases in the rate of the generation of reactive oxygen species. These results may suggest that mitochondria enlarged to various degrees and normal-sized ones are functionally similar to each other and that the MG fraction obtained by a routine isolation procedure for normal mitochondria can be applied to the study of the function of MG.

Animals↗