Action Of Formaldehyde Research Articles

Synthesis of Tetrazinyl Biradicals Containing 1,1′-Biphenyl Fragment

4,4′-([1,1′-Biphenyl]-4,4′-diyl)bis(6-aryl-2-phenyl-5,6-dihydro-1,2,4,5-tetrazin-1-2H-yls) were obtained from bis(triflates) 1,1′-([1,1′-biphenyl]-4,4′-diyl)bis(3-aryl-5-phenyl-5,6-dihydro-1, 2,4,5-tetrazinium-1) synthesized from the corresponding 1,1′-([1,1′-biphenyl]diyl-4,4′)bis(3-aryl-5-phenylformazane). It was found that binuclear tetrazinium salts are formed by the action of formaldehyde and CF3SO3H on formazans, while mononuclear salts are formed by the action of HClO4. Tetrazinyl diradicals were isolated in the individual state and characterized by elemental analysis, IR and ESR spectroscopy.

AMINOMETHYLATION OF DIHYDROXYACETOPHENONES

Aminomethylation of trifunctional 2.5-dihydroxyacetophenone (2.5-DHA) and 2.4-dihydro¬xy¬aceto-phenone (2.4-DHA) by free primary and secondary amines in the presence of formaldehyde has been conducted for the first time. It has been established that 2.5-DHA is aminomethylated with secondary heterocyclic amines - piperidine and morpholine and with aqueous formaldehyde solution in alcohol medium at 500C. The reaction proceeds simultaneously via all three functions forming stable C,O-substitution products − β-amino-2-aminomethoxy-4-aminomethyl-5-hydroxypropiophenones. The aminomethylation reaction of 2.4-DHA proceeds by phenolic function only under the action of methylene bis-amines piperidine and morpholine in absolute alcohol at 200C with the formation of 2.4-dihydroxy-3-aminomethylacetophenones. Aminomethylation of 2.4-DHA with primary aromatic amines - n-to¬luidine and n-anisidine proceeds in absolute alcohol under the action of formaldehyde in the form of paraform in the presence of catalytic amounts of KOH at 500C. The reaction products are 3.4-dihydro-2H-1.3-benzoxazines. 2.5-DHA does not react with primary aromatic amines and formaldehyde. The composition and structure of compounds synthesized have been established according to the data of ele¬mental and spectral methods of analysis

Optical properties of NiOOH films in formaldehyde solutions

Films of nickel hydroxide have been obtained by electrodeposition. The analysis of interferograms, optical spectra, XRD analysis and the SEM of the obtained films showed that the deposition of films with ~ 10−5 mol/L PcNi(SO3Na)4 in the Ni(NO3)2 solution helps to control the formation of uniform Ni(OH)2 films with dominance structure of α-Ni(OH)2. The studies of the kinetics of optical changes of NiOOH films in aqueous formaldehyde solutions showed that due to the reaction of NiOOH with formaldehyde, its color changes. It was established that the dependence of the rate of change of light transmittance, ΔT/Δt, on the concentration of formaldehyde is linear in the range of 0.5–20 mmol/L. An analysis of cyclic plots of electrochemical oxidation of Ni(OH)2 to NiOOH and its reduction by the action of formaldehyde showed that the formaldehyde concentration of more than 22 mmol/L can be determined from the absolute value of light transmittance. It was established that an dominance of structure of α-Ni(OH)2 and decrease the thickness of the films to ~ 150 nm contributes by oxidation processes solutions of millimolar concentrations formaldehyde.

Macrocyclic complexes : Synthesis and characterization of cobalt(II), nickel(II) and copper(II) complexes with [14]1,4,5,7,8,11,12,14-octaaza-2,3,9,10-tetraoxo-1,4,5,6,6,7,8,11,12,13,13,14-dodecahydrocyclotetradecane (OTCT)

A series of macrocyclic complexes of the titled ligand have been isolated by the action of formaldehyde (H 2 CO) on bis-(1,4-diamino-1,4-diaza-2,3-dioxobutane) complexes of cobalt(II), nickel(II) and copper(II). The coordination template effect governs the steric course of the reaction. The structures of the complexes have been elucidated on the basis of IR, electronic, ESR spectral data, magnetic properties, electrochemical studies and thermal data. Electrochemical studies show that all the complexes show two well defined reduction curves corresponding to the formation of species where the metal ion can be formally assigned an oxidation state of +I and zero respectively.

10.1007/s11178-008-2020-9

Acid-catalyzed reaction of trifluoromethanesulfonamide with paraformaldehyde in ethyl acetate led to the formation of oxymethylated products that did not form in the reaction carried out in sulfuric acid. Following products were obtained: 5-trifluoromethylsulfonyl-1,3-dioxazinane, 3,7-bis-(trifluoromethylsulfonyl)-1,5,3,7-dioxadiazocane, and a complex of trifluoromethanesulfonamide with 2,4,8,10-tetraoxospiro[5,5]undecene, 1:1. The spiroring resulted from the cyclization of pentaerythritol under the action of formaldehyde. The pentaerythritol formed in its turn by oxymethylation of the methyl group of ethyl acetate with paraformaldehyde followed by the reduction of the COOEt group into CH2 OH by the formaldehyde.

The human lung cell line A549 does not develop adaptive protection against the DNA‐damaging action of formaldehyde

The alkaline comet assay was used to further characterize the induction of DNA-protein crosslinks (DPX) by formaldehyde (FA) and their removal in the human lung cell line A549. DPX were indirectly measured as the reduction of gamma ray-induced DNA migration. Repeated treatments of A549 cells with low FA concentrations (up to 100 microM) did not lead to significant differences in the induction of DPX in comparison with a single treatment. Pretreatment with higher FA-concentrations (200 microM and above) enhanced the crosslinking effect. There was no indication for an adaptive protection against the induction of DPX by FA. These findings are in agreement with RT-PCR measurements of the expression of genes that encode the main enzymes involved in FA detoxification. A549 cells exposed to FA (50-300 microM) for 1, 4, or 24 hr did not reveal altered expression of the GSH-dependent formaldehyde dehydrogenase (FDH, which is identical to alcohol dehydrogenase 3; ADH3), the cytosolic aldehyde dehydrogenase 1 (ALDH1A1) and the mitochondrial ALDH2. Pretreatment of A549 cells with a low FA concentration (50 microM) also did not enhance the removal of DPX induced by higher FA concentrations. Taken together, these results suggest that A549 cells do not develop adaptive protection against the genotoxic action of FA. Neither metabolic inactivation of FA nor the repair of FA-induced DPX seems to be enhanced in cells pretreated with FA.

Synthesis and characterization of transition metal complexes of a 16-membered (N4 macrocycle with tetrapeptide features

A series of macrocyclic complexes of the titled ligand, [16]1,5,6,8,9,13,14,16-octaza-2,4,10,12-tetraoxo-cyclo decahexane (OTCH) with cobalt(II), nickel(II) and copper(II) have been prepared by the action of formaldehyde on the respective bis(1,5-diumino-1,5-diaza-2,4-dioxopentane) metal complexes. The coordination template effect governs the steric course of the reaction. The structure of the complexes has been elucidated on the basis of IR, electronic and ESR spectral data, magnetic properties and electrochemical studies. All the complexes except copper(II) give two well defined reduction steps corresponding to the formation of a species where the metal can be formally assigned to an oxidation state of +1 and zero. Copper(II) complexes show one reduction step corresponding to zero oxidation state.

Further characterization of the genotoxicity of formaldehyde in vitro by the sister chromatid exchange test and co-cultivation experiments

The induction of sister chromatid exchanges (SCE) was used to further characterize the genotoxic action of formaldehyde (FA) on cultured mammalian cells. FA induced SCE in V79 Chinese hamster cells and A549 human lung cells in a concentration-related manner. Addition of 5-bromodeoxyuridine (BrdUrd) for the differentiation of sister chromatids to visualize SCE 4 h after the FA treatment led to a clearly reduced induction of SCE in agreement with the repair kinetics of FA-induced DNA-protein cross-links. When A549 cells were treated with FA for 1 h and then co-cultivated with V79 cells in the presence of BrdUrd, a clear induction of SCE was measured in V79 cells. When the same experiment was performed including washing and change of medium after the FA treatment, no induction of SCE was measured in V79 cells. These results indicate that reactive FA remains in the cell culture medium for a longer time period despite the high reactivity of FA with macromolecules. However, FA that has entered a cell is not released and does not damage other cells. Possible implications for the mutagenicity of FA in vivo will be discussed.

Oxymethylation of trifluoromethanesulfonamide with paraformaldehyde in ethyl acetate

Acid-catalyzed reaction of trifluoromethanesulfonamide with paraformaldehyde in ethyl acetate led to the formation of oxymethylated products that did not form in the reaction carried out in sulfuric acid. Following products were obtained: 5-trifluoromethylsulfonyl-1,3-dioxazinane, 3,7-bis-(trifluoromethylsulfonyl)-1,5,3,7-dioxadiazocane, and a complex of trifluoromethanesulfonamide with 2,4,8,10-tetraoxospiro[5,5]undecene, 1:1. The spiroring resulted from the cyclization of pentaerythritol under the action of formaldehyde. The pentaerythritol formed in its turn by oxymethylation of the methyl group of ethyl acetate with paraformaldehyde followed by the reduction of the COOEt group into CH2 OH by the formaldehyde.

Simultaneous determination of formaldehyde and methanol by flow-injection catalytic spectrophotometry

A flow-injection method is proposed for the simultaneous catalytic determination of formaldehyde and methanol on the basis of the catalytic action of formaldehyde upon the redox reaction between crystal violet and potassium bromate in a phosphoric acid medium and on-line oxidization of methanol into formaldehyde using a lead dioxide solid-phase reactor. The indicator reaction is monitored spectrophotometrically by measuring the decrease in the absorbance of crystal violet at the maximum absorption wavelength of 610 nm. A technique based on three sampling loops with a single injection valve is developed. The flow-injection system produces a signal of main peak with two shoulders of the same height. The height of the shoulders corresponds to the formaldehyde concentration, and the height difference between the shoulders and the main peak corresponds to the methanol concentration. The detection limit is 0.1 μg/mL for formaldehyde and 1.0 μg/mL for methanol with the sampling rate of 10 samples per hour. The relative standard deviations for 11 replicate determinations of formaldehyde (1.0 μg/mL) and methanol (10 μg/mL) are 1.1 and 2.1%, respectively. The method has been successfully applied to the simultaneous determination of formaldehyde and methanol in some gas samples.

The release of flavin adenine dinucleotide upon local conformational transition in electron-transferring flavoprotein induced by trimethylamine dehydrogenase

The electron-transferring proteins, trimethylamine dehydrogenase (TMAD) and electron-transferring flavoprotein (ETF) from the bacterium Methylophilius methylotrophus, were studied in vitro by fluorescence spectroscopy. Flavin adenine dinucleotide (FAD) was found to be capable of a slow and spontaneous release from ETF, which is accompanied by an increase in flavin fluorescence. At a rather high ionic strength (0.1 M NaCl or 50 mM phosphate), the FAD release is sharply activated by TMAD preparations that induce a local conformational transition in ETF. The values of tryptophan fluorescence polarization and lifetime and the use of the Levshin-Perrin equation helped show that the size of protein particles remain unchanged upon the TMAD and ETF mixing; i.e., these proteins themselves do not form a stable complex with each other. The protein mixture did not release flavin from ETF in the presence of trimethylamine and formaldehyde. In this case, a stable complex between the proteins appeared to be formed under the action of formaldehyde. Upon a short-term incubation of ETF with ferricyanide, FAD was hydrolyzed to flavin mononucleotide (FMN) and AMP. This fact explains the previous detection of AMP in ETF preparations by some researches. A fluorescence method was proposed for distinguishing FAD from FMN in solution using ethylene glycol. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 3; see also http://www.maik.ru.

Formation and repair of DNA lesions in kidneys of male mice after acute exposure to methyl chloride

The time-course of DNA lesions (DNA-protein cross-links, single-strand breaks) induced by high concentrations of methyl chloride (1000 ppm) was measured in renal tissue of male mice by means of the alkaline elution assay in order to gain an insight into repair processes. DNA-protein cross-links were removed at a fast rate, whereas single-strand breaks appeared to accumulate, even during repair of DNA-protein cross-links. However, 48 h after exposure to methyl chloride, neither of these lesions were detectable in mouse kidney. Both types of DNA damage were ascribed to the action of formaldehyde, an intermediate in methyl chloride metabolism which may react with nucleic acids and protein and interfere with DNA repair.

Genotoxic action of formaldehyde in exposed children

Genotoxic action of formaldehyde in exposed children

Ligand exchange chromatography for analysis and preparative separation of tritium-labelled amino acids

Racemic tritium-labelled amino acids were separated into optical isomers by chromatography on a chiral polyacrylamide sorbent filled with copper ions. The polyacrylamide sorbent is synthesized by Mannich's reaction through the action of formaldehyde and L-phenylalanine upon polyacrylamide Biogel P-4 in an alkali phosphate buffer. Tritiumlabelled amino acids are eluted by a weak alkali solution of ammonium carbonate. Data are presented on the ligand exchange chromatography of amino acids depending on the degree to which the sorbent is filled with copper ions and on the eluent concentration. Conditions are suggested for the quantitative separation of amino acid racemates. Amino acids are isolated from the eluent on short columns filled with sulfonated cation exchanger in the H+ form. HPLC on modified silica gel sorbents is also used for the analysis of tritium-labelled optically active amino acids. Amino acids are eluted by a weakly acidic water-methanol solution containing ammonium acetate. UV and scintillation flow type detectors are used.

Effects of formaldehyde on bronchial ion transport

The functions of the epithelium that lines mammalian airways are potential targets for the toxic effects of reactive chemicals such as formaldehyde. We examined the effects of formaldehyde on bioelectric properties and ion permeation of excised canine and human bronchial epithelium. Concentration-dependent reductions in short-circuit current were induced in both tissues. Sodium absorption and transcellular chloride fluxes across canine bronchial epithelium were inhibited by 65 and 35%, respectively, by 10 −3 m formaldehyde. The Q O 2 of isolated dog bronchial epithelial cells was reduced by 32% by 10 −3 m formaldehyde. These results are consistent with an action of formaldehyde on cellular ion permeability but effects secondary to metabolic inhibition cannot be dismissed.

State of cardiac pyridine nucleotides and flavoproteins during preservation in 0.5% formalin solution

Possibilities of formaldehyde interaction with the respiratory link of mitochondria were studied. For this purpose the fluorescent technique was used to examine pyridine nucleotides and flavoproteins of the conserved heart. The data obtained indicate that the action of formaldehyde on oxidation myocardial cell metabolism appears to be related to the inhibition of the glycolytic apparatus.

The action of formaldehyde on staphylococcal delta haemolysin.

Native staphylococcal delta haemolysin was poorly immunogenic in the mouse. After treatment with formaldehyde at pH 5 or pH 7.5, haemolytic activity was rapidly lost but antigenic reactivity retained and, at pH 5, immunogenicity was enhanced. Treatment of the haemolysin with formaldehyde at pH 9.5 reduced haemolytic activity by 97% but did not enhance immunogenicity. There was no evidence of polymerisation of formaldehyde-treated delta haemolysin, and the enhanced immunogenicity was considered to be partly due to a reduced affinity for phospholipids.

Anti-N in patients undergoing regular haemodialysis—A possible association with early transplant failure

Anti-N is a relatively uncommon antibody. However, its occurrence in patients undergoing regular haemodialysis and its possible association with early transplant failure have been recognized. Small accumulations of red cells remain in the dialyser even after intensive flushing and it is postulated that these cells altered by the action of formaldehyde are inadvertently reinfused to the patient who may then develop the blood group antibody. In 1978, over a period of 8 mth, 72 patients on the haemodialysis programme at the Auckland Hospital were screened for the presence of red cell antibodies that were reactive at room temperature or above. Of these, 6 were detected to have Anti-N. During this period the patients had undergone renal dialysis up to 3 times per wk with reuse of the dialysers which were sterilized using 2% formaldehyde. Prior to transplantation all patients underwent compatibility testing against donor cells. Tissue typing and matching were performed by routine microlymphocyto-toxicity methods. Five of these patients subsequently underwent renal transplantation. In 4 patients the kidneys never functioned adequately. Histological studies done on the kidneys that failed to function showed thrombosis of renal vessels and cortical infarction. The clinical pattern seen in the patients and the above histological findings may be compatible with thrombosis of the renal vessels, due to anti-N reacting with the red cells in the cold kidney at the time of transplantation. It is not possible to be certain of the role of anti-N antibodies if any, in the failure of these transplants, but it is suggested that careful screening for the presence of anti-N is done in patients who have undergone chronic haemodialysis. A policy has now been adopted that in any patient with anti-N, kidneys to be transplanted are pre-warmed to approximately 20°C before the renal circulation is established.

Relaxation in biological macromolecules and application of theory to the investigation of secondary structure of DNA

Using a statistical mechanical approach we have shown that, in the case of large perturbations, the fraction of helicity at time t can be factored into two terms—a chain length dependent term which is a function of the dispersity of macromolecules and a sigmoidal term which depends on the nucleation parameter, σ, but not on chain lengths. The analytic expression for the fraction of helicity obtained from our approach is very similar to that obtained by Trifonov et al. for an irreversible conformational transformation. Our approach, however, uses one less parameter than that of Trifonov et al. and, moreover, is applicable to the reversible as well as irreversible cases. We have applied our theory to the denaturation of DNA under the action of formaldehyde and found excellent agreement between the theory and experiment.

Theoretical study of DNA unwinding under the action of formaldehyde

A consistent theory of DNA unwinding under the action of formaldehyde which makes possible calculation of all characteristics of the process based on a given nucleotide sequence has been developed. The kinetic parameters are obtained with the use of the theory of helix-coil transition in DNA. These parameters are then employed for obtaining the final characteristics of the unwinding process by formaldehyde, the kinetic curves of unwinding (and their anamorphoses) and the maps of denaturation. The calculations which were performed for heteropolynucleotides with random sequences and with different concentrations of defects revealed that a simple theory previously developed for the homopolymer case, is also valid for the heteropolymer. This result agrees with the experimental data and justifies, from the theoretical point of view, applications of the kinetic formaldehyde method to the natual DNAs. Denaturation maps have also been calculated which demonstrated that a purely random sequence proved to give only slightly noticeable singularities. However, the insertion of the AT clusters (the regions consisting of 20–40 AT pairs) into the random sequence gives rise to the clear-cut peaks on the maps. The magnitude of such a peak drops sharply if only a few GC pairs are present within the AT cluster. Electron microscopic mapping data obtained by the Inman method, have been discussed on the basis of the above theoretical results. This consideration allows one to attribute the sharp peaks on the denaturation maps to T7 phage DNA as originated from the AT clusters.