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PubMed2006

Synthesis, structure-activity relationships, and antitumor studies of 2-benzoxazolyl hydrazones derived from alpha-(N)-acyl heteroaromatics.

Recently we have described the antitumor activities of 2-benzoxazolylhydrazones derived from 2-formyl and 2-acetylpyridines. In search of a more efficacious analogue, compounds in which the 2-acetylpyridine moiety has been replaced by 2-acylpyridine and alpha-(N)-acetyldiazine/quinoline groups have been synthesized. The 2-acylpyridyl hydrazones inhibited in vitro cell proliferation in the nM range, whereas the hydrazones derived from the alpha-(N)-acetyldiazines/quinolines inhibited cell growth in the muM range. Compounds tested in the NCI-60 cell assay were effective inhibitors of leukemia, colon, and ovarian cancer cells. E-13k [N-benzoxazol-2-yl-N'-(1-isoquinolin-3-yl-ethylidene)-hydrazine] inhibited the proliferation of MCF-7 breast carcinoma cells more efficiently than nontransformed MCF-10A cells. It is not transported by P-glycoprotein and a weak MRP substrate. Increased concentrations of serum or alpha(1)-acid glycoprotein did not reduce the antiproliferative activity of the compound. In the in vivo hollow fiber assay, E-13k achieved a score of 24, with a net cell kill of OVCAR-3 (ovarian) and SF2-95 (CNS) tumor cells.

Antineoplastic Agents↗
PubMed1997

Azinyl and diazinyl hydrazones derived from aryl N-heteroaryl ketones: synthesis and antiproliferative activity.

A series of N-heteroaryl hydrazones derived from aryl N-heteroaryl or bis-N-heteroaryl methanones was prepared in search for potential novel antitumor agents. The stereochemistry of these compounds was established by means of NMR spectroscopy. Antiproliferative activity was determined in a panel of human tumor cell lines (CCRF-CEM, Burkitt's lymphoma, HeLa, ZR-75-1, HT-29, and MEXF 276L) in vitro. Generally, the new compounds were found to be more potent (IC50 = 0.011-0.436 microM) than the ribonucleotide reductase inhibitor hydroxyurea (IC50 = 140 microM). Most of the compounds exhibited the highest activity against Burkitt's lymphoma with an IC50 of 0.011-0.035 microM. [14C]Cytidine incorporation into DNA was quantitated for selected hydrazones (Z-A, E-1, Z-3, Z-4, E-5, Z-5, E-13, E-18, Z-19, Z-24, and E-26) as a measure of the inhibition of ribonucleotide reductase in Burkitt's lymphoma cells. The E-configurated compounds were found to inhibit [14C]cytidine incorporation to a greater extent (IC50 = 0.67-5.05 microM) than the Z-isomers (IC50 = 7.20 to > 10 microM). Principal component analysis of the IC50 values obtained for inhibition of cell proliferation revealed that the cell lines tested can be grouped into three main families showing different sensitivities toward the compounds in our series [(i) CCRF-CEM, Burkitt's lymphoma, and Hela; (ii) HT-29; and (iii) MEXF 276 L].

Antineoplastic Agents↗
PubMed1998

Binding of carbohydrates to solid supports Part 3: Reaction of sugar hydrazones with polystyrene substituted with aromatic aldehydes.

The hydrazones of glucose and N-acetylglucosamine, as models for the residues at the reducing termini of glycans, were covalently and reversibly bound in good yield to hydroxybenzaldehydo ligands attached to a polymer support. The binding, by a sugar azine linkage, occurred within two hours at room temperature at neutral pH, and efficient recoveries of sugars from the beads were achieved by displacement with aqueous hydrazine hydrate, ethanolic benzaldehyde, or aqueous acetone. Enzyme modification of glycans was demonstrated by separation of the products of hydrolysis of lactose hydrazone with beta-galactosidase, using hydroxybenzaldehyde-derivatized polystyrene beads. Addition of a spacer arm to aminopolystyrene beads, for binding of reducing sugars as Amadori compounds to the aromatic amine function, was also investigated.

Acetylglucosamine↗
PubMed2001

Determination of airborne formaldehyde by active sampling on 3-methyl-2-benzothiazolinone hydrazone hydrochloride-coated glass fibre filters.

Formaldehyde was sampled with the use of a standard miniature glass fibre filter coated with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH). The formaldehyde hydrazone formed [i.e., the adduct of formaldehyde (HCHO) and MBTH] was desorbed from the filter with water and then oxidised by an iron(III) chloride-sulfamic acid solution to form a blue cationic dye in acidic medium which was subsequently determined by visible absorption at 628 nm. The recovery of HCHO as the cationic dye from MBTH-coated filters is 87-102% in the range 0.065-2.9 micrograms of HCHO. This corresponds to 4.3-193.3 micrograms m-3 in a 15 L air sample. The collection efficiency of the MBTH-coated filter is higher than 90%. When the filter sampling system is used in active mode, air can be sampled at a rate of up to 1 L min-1, affording an overall sensitivity of about 3 micrograms m-3, corresponding to about 2 ppb v/v HCHO at 1 atm and 273 K. The method was successfully applied to the determination of HCHO in samples of indoor and outdoor air with satisfactory results.

Air Pollutants↗
PubMed1990

Phosgene (chlorophenyl)hydrazones, strong sensitizers found in yellow sweaters bleached with sodium hypochlorite, defined as causative allergens for contact dermatitis by an experimental screening method in animals.

12 young men developed allergic contact dermatitis from wearing yellow cotton sweaters. We attempted to identify the causative agents by an experimental screening method in animals. Guinea pigs were sensitized with an acetone extract of the sweater material, by means of the guinea pig maximization test (GPMT). Active ingredients were then separated from the extract, by step-by-step patch test screening of chromatographic fractions in the guinea pigs, and finally analyzed by gas chromatography-mass spectrometry (GC-MS). Although there were 2 allergens with important activity (1 in the fraction eluted from the silica gel column with hexane, and 1 in the methanol fraction), the present study is focussed on the fat-soluble allergens in the hexane fraction. GC-MS analysis revealed that 4 kinds of phosgene (chlorophenyl)hydrazones (PCPHs) were present in the hexane fraction. PCPHs prepared in our laboratory showed strong eliciting activities, not only in the guinea pigs sensitized with the extract, but also in a male volunteer sensitized by exposure to a yellow sweater during irritancy testing. Phosgene (2,5-dichlorophenyl)hydrazone, which was the main component among the PCPHs found in the sweater, sensitized guinea pigs even at the 1 ppm level. From these results, we conclude that PCPHs were one of the allergens responsible for the cases.

Animals↗
PubMed2002

N-arylsulfonyl hydrazones as inhibitors of IMP-1 metallo-beta-lactamase.

Members of a family of N-arylsulfonyl hydrazones have been identified as novel inhibitors of IMP-1, a metallo-beta-lactamase of increasing prevalence. Structure-activity relationship studies have indicated a requirement for bulky aromatic substituents on each side of the sulfonyl hydrazone backbone for these compounds to serve as efficient inhibitors of IMP-1. Molecular modeling has provided insight into the structural basis for the anti-metallo-beta-lactamase activity exhibited by this class of compounds.

Bacillus cereus↗
PubMed2004

High-energy collision-induced dissociation of oxosteroids derivatised to Girard hydrazones.

Neutral oxosteroids have been derivatised with Girard T and P hydrazine reagents to give the corresponding Girard hydrazone quaternary ammonium salts. Both Girard T (GT) and Girard P (GP) hydrazones of oxosteroids give very intense [M](+) ion signals in electrospray (ES) mass spectra and fragment within the ES interface and collision cell to give characteristic fragment ions. GT and GP derivatives give informative high-energy collision-induced dissociation spectra, from which the structure of the precursor oxosteroid can be determined. Both charge-remote and charge-mediated mechanisms are responsible for the formation of the fragment ions at high collision-energy.

Hydrazones↗
PubMedDate not supplied

[New isatin-derived hydrazones and Mannich bases with possible biological activity].

The paper presents a synthesis of six new Mannich bases, five hydrazones derived from 1-piperidino-methyl-5-R-isatin and three copper complex compounds of 3-(3'-R-phenyl-pyridazinil-hydrazone)-indoline-2-ones (R=H, CH3, OCH3). The structure of the new compounds was confirmed by the results of the elementary and spectral analysis. Pharmacodynamic studies indicated that copper complex compounds present effective biological properties. Thus, it can be seen that the experimental carrageenan-induced inflammatory oedema was 58.3% inhibited by the complex V (R=CH3) after oral administration. Antimicrobial tests revealed that only compound V (R=OCH3) shows a moderate antimicrobial activity against the gram-positive and gram-negative bacteria, used in the test.

Animals↗
PubMed2003

A study of potential toxic effects after repeated 10-week administration of a new iron chelator--salicylaldehyde isonicotinoyl hydrazone (SIH) to rabbits.

Salicylaldehyde Isonicotinoyl Hydrazone (SIH)--a Pyridoxal Isonicotinoyl Hydrazone (PIH) analogue--is an effective iron chelator with antioxidant and antimalarial effects, as documented in numerous in vitro studies. However, no toxicological data obtained from in vivo studies have been made available yet. In this study, the potential toxic effects of repeated administration of SIH (50 mg/kg, once weekly, 10 weeks, i.p.), partially dissolved in a 10% Cremophor solution, on various biochemical, haematological, and cardiovascular parameters and on morphology of selected tissues were investigated in rabbits. The obtained values were compared with data from the control (saline, 1 ml/kg, i.v.) and the Cremophor (10% Cremophor solution, 2 ml/kg, i.p.) groups. In this study, SIH did not induced marked signs of toxicity: No premature deaths occurred, the body weight increase was comparable with the control and Cremophor groups. Only few and mild changes in some biochemical and haematological parameters could be determined, most of them were noticed also in the control or Cremophor groups. The morphological changes in the kidney were mild and did not manifest in the biochemical examination. The cardiac function was also not affected markedly--the values of left ventricular ejection fraction and systolic time interval did not differ from the values of control group. Only an increased left ventricular contractility (dP/dtmax) was noticed in the SIH group at the end of the experiment as compared to the controls (13,354+/-1191 vs. 9339+/-647 mmHg/s, resp.). These results seem to be promising from the standpoint of possible clinical use of SIH.

Aldehydes↗
PubMed2005

[Synthesis of 2,3,4-trihydroxyacetophenone hydrazones and study on their spectral properties].

2,3,4-Trihydroxyacetophenone was synthesized with pyrogallol. Benzoylhydrazone and p-hydroxybenzoylhydrazone were synthesized using the reaction of ethyl benzoate and methyl p-hydroxybenzoate with hydrazine hydrate. Three novel 2,3,4-trihydroxyacetophenone hydrazones were synthesized using the reaction of 2,3,4-trihydroxyacetophenone with benzoylhydrazone, p-hydroxybenzoylhydrazone and phenylhydrazine. IR, UV and the fluorescence spectrum of 2,3,4-trihydroxyacetophenone hydrazones were studied.

Acetophenones↗
PubMed1989

Synthesis of polyamine-linked bis-daunomycin hydrazones and their interaction with DNA.

A series of bis-anthracycline hydrazones were prepared, compounds 9, containing either two or three secondary amines in the linker chain as well as the corresponding acetyl (10), or benzoyl (11) protected derivatives. Compounds 9 could not be isolated in pure form as they decomposed during semi-preparative h.p.l.c. Compounds 10a-g and 11b were characterized by f.a.b. mass spectrometry. All compounds bis-intercalated into DNA as judged by viscometric lengthening of DNA and by decreased dissociation kinetics from DNA under conditions of SDS sequestration. The secondary amine containing derivatives (9) exhibited dissociation rates less than 10(-5) that of daunomycin. The apparent affinity of these compounds was so great that the dissociation constants could not be quantitated, and they were only liberated from DNA to monomeric species by a slow hydrolysis process of the hydrazone links. Protection of those derivatives containing two amines in the linker by acetyl (10) and benzoyl (11) groups, decreased the dissociation time constant to 490-2900 s (1400-8000 fold slower than daunomycin) with maximal DNA residence time corresponding to a linker length of 14 atoms (approximately 14 A). Addition of a third protected amine in the linker, compound 10g, enhanced the DNA residence time a further three-fold. In vitro inhibition of transcription analysis showed that all of the bis-anthracyclines exhibited a DNA sequence specificity for 5'-CpA-3' sites, with adjacent intercalation sites decreasing in the order CA greater than AC, TC greater than CT greater than GC, CG, CC, TA, and it is apparent that the presence of the basic amino functions in the bridging chain provides for greatly enhanced formation of the drug-DNA complex.

Antibiotics, Antineoplastic↗
PubMedDate not supplied

[Radioprotective efficacy of acyl hydrazones].

As was shown in experiments with rats and mice some acyl hydrazones have a pronounced radioprotective effect. The protective efficiency makes 40-55 per cent with the preparation doses of 1-10 mg/kg. The toxicity of hydrazones is 2 g/kg which is lower, than that of the known sulfur-containing agents and substituted indolylalkylamines. The radio-protective efficiency of the drug depends on its complex-forming ability.

Animals↗
PubMed2005

Mixed-valence, mixed-spin-state, and heterometallic [2x2] grid-type arrays based on heteroditopic hydrazone ligands: synthesis and electrochemical features.

An extended family of heterometallic [(M1)2(M2)2(L-)4](n+) [2x2] grid-type arrays 1-9 has been prepared. The three-tiered synthetic route encompasses regioselective, redox and enantioselective features and is based on the stepwise construction of heteroditopic hydrazone ligands A-C. These ligands contain ionisable NH and nonionisable NMe hydrazone units, which allows the metal redox properties to be controlled according to the charge on the ligand binding pocket. The 2-pyrimidine (R) and 6-pyridine (R') substituents have a significant effect on complex geometry and influence both the electrochemical and magnetic behaviour of the system. 1H NMR spectroscopic studies show that the Fe(II) ions in the grid can be low spin, high spin or spin crossover depending on the steric effect of substituents R and R'. This steric effect has been manipulated to construct an unusual array possessing two low-spin and two spin-crossover Fe(II) centres (grid 8). Electrochemical studies were performed for the grid-type arrays 1-9 and their respective mononuclear precursor complexes 10-13. The grids function as electron reservoirs and display up to eight monoelectronic, reversible reduction steps. These processes generally occur in pairs and are assigned to ligand-based reductions and to the Co(III)/Co(II) redox couple. Individual metal ions in the heterometallic grid motif can be selectively addressed electrochemically (e.g., either the Co(III) or Fe(II) ions can be targeted in grids 2 and 5). The Fe(II) oxidation potential is governed by the charge on the ligand binding unit, rather than the spin state, thus permitting facile electrochemical discrimination between the two types of Fe(II) centre in 7 or in 8. Such multistable heterometallic [2x2] gridlike arrays are of great interest for future supramolecular devices incorporating multilevel redox activity.

Journal Article↗
PubMed2005

Synthesis, structural features, absorption spectra, redox behaviour and luminescence properties of ruthenium(ii) rack-type dinuclear complexes with ditopic, hydrazone-based ligands.

The isomeric bis(tridentate) hydrazone ligand strands 1 a-c react with [Ru(terpy)Cl3] (terpy=2,2':6',2''-terpyridine) to give dinuclear rack-type compounds 2 a-c, which were characterised by several techniques, including X-ray crystallography and NMR methods. The absorption spectra, redox behaviour and luminescence properties (both in fluid solution at room temperature and in rigid matrix at 77 K) of the ligand strands 1 a-c and of the metal complexes 2 a-c have been studied. Compounds 1 a-c exhibit absorption spectra dominated by intense pi-pi* bands, which, in the case of 1 b and 1 c, extend within the visible region, while the absorption spectra of the rack-type complexes 2 a-c show intense bands both the in the UV region, due to spin-allowed ligand-centred (LC) transitions, and in the visible, due to spin-allowed metal-to-ligand charge-transfer (MLCT) transitions. The energy position of these bands strongly depends on the ligand strand: in the case of 2 a, the lowest energy MLCT band is around 470 nm, while in 2 b and 2 c, it lies beyond 600 nm. Ligands 1 a-c undergo oxidation processes that involve orbitals based mainly on the CH3--N--N== fragments. The complexes 2 a-c undergo reversible metal-centred oxidation, while reductions involve the hydrazone-based ligands: in 2 b and 2 c, the bridging ligand is reduced twice and in 2 a once before reduction of the peripheral terpy ligands takes place. Ligands 1 a-c exhibit luminescence from the lowest-lying 1pi-pi* level. Only for complex 2 a does emission occur; this may be attributed to a 3MLCT state involving the bridging ligand. Taken together, the results clearly indicate that the structural variations introduced translate into interesting differences in the spectroscopic, luminescence and redox properties of the ligand strands as well as of the rack-type metal complexes.

Journal Article↗
PubMed1983

Structure of the isonicotinyl hydrazone of norethindrone.

The contraceptive steroid norethindrone reacts with isoniazid both in vivo and in vitro to give the corresponding hydrazone, which exists as syn and anti (with respect to C-4) isomers. These isomers rapidly interconvert, with the anti form predominating in solution. The identification of the isomers was based on an interpretation of 1H- and 13C-NMR spectroscopic data and corroborated by high-performance liquid chromatographic UV spectrophotometric evidence. 1H- and 13C-NMR spectroscopic data for other derivatives of norethindrone hydrazone are presented and interpreted.

Chemical Phenomena↗
PubMed1989

Pharmacokinetics and biotransformation of hydralazine acetone hydrazone, a metabolite of hydralazine, in the rat.

The pharmacokinetics of hydralazine acetone hydrazone (HAH), which is a metabolite of hydralazine (HP), was investigated after iv administration to rats. Plasma concentrations of HAH, HP, and hydralazine pyruvic acid hydrazone (HPH) were simultaneously determined by a specific HPLC method. A five-compartment pharmacokinetic model was presented to elucidate the disposition of HAH and two products, HP and HPH. The parameters used in the model were obtained by administering each of the three compounds (10 mg/kg) separately. The proposed model described the experimental data well and the model parameters were close to the model-independent values. After HP administration, HPH appeared rapidly in plasma, but the HPH availability from HP amounted to only 17.8 +/- 3.7%, based on the comparison between the area under the plasma concentration curves of formed and iv HPH. The formation of HP from HAH in the systemic circulation was demonstrated, but formed HP disappeared rapidly. The fraction of HAH available to the systemic circulation as HPH was extremely low (7.8 +/- 2.2%), indicating that the conversion of HAH to HP was not so extensive. The present results support the hypotheses that HPH is formed via the direct reaction of HAH with pyruvic acid and that the secondary formation is mediated by conversion to HP.

Animals↗