Showing papers on "Acrylamide published in 1985"

Direct Alkylation of 2′-Deoxynucleosides and DNA following in Vitro Reaction with Acrylamide

Abstract: Reaction of the rodent carcinogen acrylamide (AM) at pH 7.0 and 37°C for 10 and 40 days with 2′-deoxyadenosine (dAdo), 2′-deoxycytidine (dCyd), 2′-deoxyguanosine (dGuo), and thymidine (dThd) resulted in the formation of 2-formamidoethyl and 2-carboxyethyl adducts via Michael addition. The alkylated 2′-deoxynucleoside adducts isolated (% yield after 40 days) were 1-(2-carboxyethyl)-dAdo (1-CE-dAdo) (8%), N6-CE-dAdo (21%) (via Dimroth rearrangement of 1-CE-dAdo), 1-CE-dGuo (4%), 7-(2-formamidoethyl)-Gua (7-FAE-Gua) (6%), 7,9-bis-FAE-Gua (1%) (formed by reaction of AM with depurinated 7-FAE-Gua during the course of the reaction), and 3-FAE-dThd (4%). The products isolated following in vitro reaction of AM with calf thymus DNA at pH 7.0 and 37°C for 40 days were (nmol/mg DNA) 1-CE-dAdo (5.5), N6-CE-dAdo (1.4), 3-CE-dCyd (2.8), 1-CE-dGuo (0.3), and 7-FAe-Gua (1.6). Compound 3-FAE-dThd was not detected. Structures were assigned on the basis of chemical properties, UV spectra, and electron impact, chemical ionization, desorption chemical ionization, Californium-252 fission fragment ionization, and fast atom bombardment mass spectra. A facile hydrolysis of the amide group to a carboxylic acid was observed when AM alkylated a ring nitrogen adjacent to an exocyclic nitrogen atom. In previous studies, we had observed an analogous phenomenon when studying the in vitro reactions of acrylonitrile with DNA, i.e., a facile hydrolysis of nitrile to carboxylic acid when acrylonitrile alkylated (via Michael addition) a ring nitrogen adjacent to an exocyclic nitrogen. Since the nitrile group hydrolyzes to a carboxylic acid via an amide intermediate, we had hypothesized in the present study that the same facile hydrolysis of amide to carboxylic acid would occur under identical stereochemical conditions as had occurred with the nitrile group. Thus, in vitro alkylation of calf thymus DNA by both acrylonitrile and, in the present study, AM, resulted in mixed adduct formation.

Mutagenicity of acrylamide and its analogues in Salmonella typhimurium

Abstract: Acrylamide and its 15 analogues have been tested for mutagenicity in 5 TA strains of Salmonella typhimurium. Acrylamide, N-tert-butylacrylamide, crotonamide, diacetone acrylamide, N,N-diethylacrylamide, N,N-dimethylacrylamide, N-hydroxymethylacrylamide, N-methylacrylamide, N-isobutoxymethylacrylamide, N-isopropylacrylamide, methacrylamide, N,N'-methylene-bis-acrylamide and N-tert-octylacrylamide appeared not to be mutagenic in the standard Ames assay both with and without Aroclor 1254-induced S9, and in both the plate incubation and liquid preincubation procedures. Three epoxide analogues, i.e., glycidamide, N,N-diglycidyl acrylamide and glycidyl methacrylamide showed mutagenicity in one or two strains both with and without the S9.

Synthèse et copolymérisation avec l'acrylamide de macromonomères d'acrylate de dodécyle

Abstract: Graft copolymers of well-defined structure and composition were prepared by radical copolymerization of acrylamide and poly(dodecyl acrylate) macromonomers The macromonomers were prepared by telomerization of dodecyl acrylate in the presence of 2-mercaptoethanol as a transfer agent, followed by reaction with acryloyl chloride Poly(dodecyl acrylate) macromonomers with Mn = 1100, 1100, 2200 and 4600 were synthesized The kinetics of the radical telomerization of dodecyl acrylate with 2-mercaptoethanol and AIBN was studied at 66°C in THF Under these conditions we obtained the transfer constant CT = 0,9 The graft copolymerization of acrylamide with the poly(dodecyl acrylate) macromonomer was carried out in the presence of the transfer agent C6F13C2H4SH If C0 = [AIBN]/[Acrylamide] = 0,01 and R0 = [C6F13C2H4SH]/[Acrylamide] = 0,01, for acrylamide a DPn = 160 was obtained in all cases, for the macromonomer of Mn = 1100 a DPn = 2,5, and for the macromonomer of Mn > 1100 a DPn = 1

Acrylamide Neuropathy in the Rat: Effects on Energy Metabolism in Sciatic Nerve

Abstract: Energy metabolism was examined in rat sciatic nerve before and after induction of neuropathy by treatment with acrylamide monomer. The in vivo activities of two glycolytic enzymes, glyceraldehyde-3-phosphate dehydrogenase and nerve-specific enolase, were resistant to acrylamide. The levels of adenosine 5′-triphosphate and creatine phosphate were also unaffected by acrylamide after either short-term or long-term treatment. The turnover of high-energy phosphate was somewhat reduced in the nerves of severely intoxicated animals. These findings cast doubt on the hypothesis that acrylamide neuropathy begins with an attack on the means of generating metabolic energy, although the eventual failure of one or more energy-consuming processes in peripheral nerve remains likely.

Hydrophobically associating terpolymers of acrylamide, salts of acrylic acid and alkyl acrylamide

Abstract: Novel water soluble terpolymers of acrylamide, an alkali metal or ammonium salt of acrylic acid and an oil soluble or hydrophobic alkyl acrylamide monomer have been found to provide efficient viscosification of water or brine solutions. The polymers are prepared by a free radical micellar polymerization of acrylamide and alkyl acrylamide followed by base catalyzed partial hydrolysis. These terpolymers, called HRAM, impart unique and useful rheological properties to aqueous solutions. In a water or brine solution the hydrophobic groups associate to increase hydrodynamic size and enhance thickening efficiency. Solutions containing the HRAM terpolymers show increased viscosification at higher polymer concentration and reduced salt sensitivity relative to polyacrylamide based HPAM solutions.

Surface characterization of styrene/acrylamide copolymer latex particles

Abstract: Surface characteristics of styrene/acrylamide copolymer latex particles prepared without emulsifier were investigated as a function of acrylamide fraction in charged monomers. The presence of swelling or water-soluble polymer layer at the particle surface was suggested, and its thickness increased with increasing acrylamide fraction. The surface charge densities by conductometric and potentiometric titrations wer about half that of polystyrene latex particles at low pH and they increased slightly with increasing pH. Regarding the heterocoagulation between styrene/acrylamide copolymer latex particles and polystyrene latex particles, the critical coagulation concentration of KCI decreased with increasing acrylamide fraction. The consideration in terms of the interaction due to electrostatic and van der Waals forces also suggested that the swelling or water-soluble polymer layer at the particle surface plays an important role.

Acrylamide diallyl dimethyl ammonium chloride copolymers as improved dewatering acids for mineral processing

Abstract: An improved method of dewatering mineral slurries which comprises treating said slurries with a dewatering amount of a copolymer of acrylamide and DADMAC, which polymers are characterized as containing from 3-50 mole percent of acrylamide and having a Reduced Specific Viscosity of at least 2.

Graft Copolymerizations of Polysaccharides. II. Acrylamide Grafting to Yellow Dextrin

Abstract: Graft copolymers of acrylamide and yellow dextrin were prepared using cerium(IV) as initiator. The yellow dextrin had a very broad molecular weight distribution but was fractionated utilizing dialysis and ultrafiltration membranes. Initiator efficiencies were determined using size exclusion chromatography and were found to be between 2.4 and 34%. Initiator efficiency increased with acrylamide concentration at constant cerium (IV) and yellow dextrin concentrations, and decreased with increasing cerium(IV) concentration at constant acrylamide and yellow dextrin concentrations. Plots of acrylamide conversion and intrinsic viscosity vs initial acrylamide concentration at constant yellow dextrin and ceric ion concentrations showed a maximum at about 2.0 M.

Biochemical studies of acrylamide neuropathy

Abstract: Studies on the toxicokinetics and biochemical effects of acrylamide are reviewed in regard to their implications concerning the mechanism of acrylamide induced neuropathy. Specifically, investigations of the effects of acrylamide on several glycolytic enzymes including neuron-specific enolase and glyceraldehyde-3-phosphate dehydrogenase are evaluated. Both of these enzymes are decreased in activity in animals exhibiting clinical signs of neuropathy induced by acrylamide. The significance of these findings in terms of the mechanism of action of acrylamide is discussed.

Inhibition of glyceraldehyde-3-phosphate dehydrogenase in tissues of the rat by acrylamide and related compounds.

Abstract: In previous investigations acrylamide was found to inhibit several enzymes of glycolysis both in vitro and in vivo. The present study examines the characteristics of the in vitro inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and compares the in vivo effects of acrylamide on GAPDH activity to other analogs. Inhibition of GAPDH produced by acrylamide was characteristic of an irreversible or slowly reversible mechanism. In vivo, GAPDH activity was determined in sciatic nerve, brain, skeletal muscle and liver after cumulative doses of 250, 350 or 500 mg/kg of acrylamide. Specific activities were significantly lower in extensor muscle and liver after the 250 mg/kg dose. Activities in brain and sciatic nerve tended to be decreased but the differences were not statistically significant. Specific activity of GAPDH was decreased in medulla pons, cerebellum and the rest of the brain after a 350 mg/kg cumulative dose of acrylamide, although protein concentrations were not different from those in controls. The maximum decrease was about 20%. Treatment with acrylamide, methylene-bis-acrylamide (non-neurotoxic), or N-isopropylacrylamide (neurotoxic) significantly decreased the weight of the cortex and associated brain areas as well as general body weights. No signs of developing neuropathy were observed during treatment with methylene-bis-acrylamide to a cumulative dose (8.1 mmoles/kg) equivalent to that of acrylamide causing frank paralysis. Although the compound exhibited some ability to inhibit GAPDH in vitro, no decrease in GAPDH activity was found in rat brain. Treatment with N-isopropylacrylamide resulted in progressive neurologic impairment. After treatment to a cumulative dose of the compound causing a severe hind-limb paralysis (9.2 mmoles/kg), a small but significant decrease in GAPDH was found in the three areas of brain examined.

Controlled modulation of the phase separation and opacification temperature of purified bovine γIV-crystallin

Abstract: In the bovine lens the γIV-crystallin fraction is a principal determinant of the phase separation and opacification temperature, TC (Siezen et al, Proc. Natl. Acad. Sci. USA 82, 1985, 1701). We have now measured the effect on TC of purified γIV-crystallin solutions produced by a variety of reagents which affect protein-protein, protein-water and water-water interactions.Ionic strengths less than physiological increase TC dramatically, while higher ionic strength has very little effect. Calcium ion concentrations up to 8 mM produce no change in TC. Glycerol and acrylamide both depress TC linearly with reagent concentrations; TC depression of γIV-crystallin by these compounds is quantitatively the same as for whole lens.Sulfhydryl reducing agents such as glutathione and dithiothreitol lower TC, while hydrogen peroxide increases TC. Changes in opacification temperature of γIV-crystallin produced by oxidizing and reducing agents are time-dependent and highly non-linear with reagent concentration.Our results c...

Effect of acrylamide and related compounds on glycolytic enzymes in rat sciatic nerve in vivo

Abstract: The effect of acrylamide and six analogues on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and enolase in sciatic nerve was examined in rats after their prolonged administration in drinking water. After 15 days' treatment with acrylamide and N-isopropylacrylamide, slight signs of peripheral neuropathy were produced with no changes in the activity of either enzyme. N,N-dimethylacrylamide, a non-neurotoxic analogue, produced only body weight loss at this stage. After 30 days' treatment, acrylamide and N-isopropylacrylamide produced moderate signs of neuropathy, but no changes in enzyme activity. N,N-dimethylacrylamide produced a reduction in GAPDH activity as well as body weight loss. After 45 days' treatment, acrylamide, N-isopropylacrylamide, N-hydroxymethylacrylamide and N-methylacrylamide produced severe signs of neuropathy as well as body weight loss. All these analogues also produced a reduction in the two enzyme activities, except for enolase after N-isopropylacrylamide. N,N-dimethylacrylamide produced inhibition of GAPDH as well as body weight loss without neuropathy. N-tert-butylacrylamide and N,N'-methylene-bis-acrylamide induced neither neuropathy nor inhibition of either enzyme.

Stabilization of iron in aqueous systems

Abstract: The copolymers are effective in stabilizing iron in solution and as antiscalants in the presence of soluble iron, the copolymers are used in amount of 1 to 200 ppm, have molecular weight of about 1,000 to 50,000, and are prepared by polymerizing 40 to 95 weight parts of an acrylic acid with 5 to 60 weight parts of a substituted acrylamide.

Effect of acrylamide and related compounds on glycolytic enzymes in mouse brain in vitro.

Abstract: The effects of acrylamide and eight analogues on mouse brain glycolytic enzymes were studied in vitro. Most of the neurotoxic and non-neurotoxic analogues showed inhibitory effects on enolases. Their inhibitory constants, I50, for both mouse brain total enolases and purified bovine neuron specific enolase were similar for each analogue, being lowest for N,N′-methylene-bis-acrylamide and highest for methacrylamide. A neurotoxic compound, N-isopropylacrylamide, and a non-neurotoxic compound, N,N′-methylene-bis-acrylamide, showed non-competitive inhibition towards mouse brain total enolase. After preincubation of anologues in vitro for 90 min with hepatic S-9 fraction prepared from normal mice, their inhibitory potency towards brain total enolase was also seen. When the S-9 fraction was prepared from mice pretreated with phenobarbital, the inhibitory potency was not different from that of the control. After preincubation with S-9 fraction prepared from either diethyl maleate-, or piperonyl butoxide-pretreated mice the inhibitory potency was significantly greater than with non-pretreated control mice. Many of the test analogues also showed inhibition of glyceraldehyde 3-phosphate dehydrogenase activity, the highest inhibitory potency being seen with acrylamide, but no compounds inhibited phosphofructokinase.

High molecular weight polyacrylamide synthesis

Abstract: This invention discloses a process for the polymerization of acrylamide and for the copolymerization of acrylamide with other monomers. It employs a ferrous/hydroperoxide redox initiator system that greatly enhances the molecular weight of the polymer formed. These high molecular weight acrylamide polymers offer outstanding advantages in enhanced oil recovery as injection water viscosifiers.

Some aspects of inverse emulsion copolymerization of acrylamide with methacrylic acid

Abstract: Inverse emulsion copolymerization studies of acrylamide (Am) with methacrylic acid (MAA) are reported. Aqueous monomer emulsions in toluene were prepared with a blend of two surfactants (sorbitan sesquioleate - Cl8 - terminated acrylamide oligomers). Polymerization kinetics in presence of an oil soluble initiator (AIBN) were determined at 40°C as function of MAA content and aqueous phase pH : monomer reactivity ratios have been derived as rAm = 0.58 ± 0.02, rMAA = 4.40 ± 0.10 at pH 4 and rAm = 0.56 ± 0.005, rMAA = 0.15 ± 0.03 at pH 10. Particle size and stability of inverse monomer emulsions and final latexes were found to depend upon the aqueous phase pH, as well as the intrinsic viscosities of the copolymers; this suggests differences in polymerization mechanism versus the pH.

Method for producing acrylamide using a microorganism

Abstract: A method is described for producing acrylamide from acrylonitrile by the action of a microorganism having nitrilase activity in an aqueous medium, which comprises conducting the reaction in the presence of an alkali metal sulfate at an ionic activity of from 0.004 to 0.01 mole per liter while controlling the pH of said aqueous medium within a range of from 7 to 9 with an alkali hydroxide.

Water-soluble copolymers. XI. Selectivity in the graft copolymerization of acrylamide/N-(1,1-dimethyl-3-oxybutyl)acrylamide comonomers onto dextran by Ce(IV)-induced initiation

Abstract: Characteristic behavior in the graft copolymerization of acrylamide/N-(1,1-dimethyl-3-oxybutyl)acrylamide (AM/DAAM) comonomers onto dextran by Ce(IV)-induced initiation was investigated From a preliminary study, it was found that ceric ammonium nitrate polymerized AM/DAAM comonomer mixtures and diacetone acrylamide, but not acrylamide alone in the aqueous solution The effect of grafting conditions on the graft copolymerization product was studied with the aid of aqueous size exclusion chromatography and the anthrone reagent The selectivity of formation of the graft copolymer over random copolymer was found to increase as the reaction temperature and AM/DAAM ratio increased and as both the Ce(IV)/Dextran molar ratio and HNO3 concentration decreased After establishing optimum grafting conditions, graft copolymer samples were prepared, and their aqueous solution behavior studied as functions of structure, temperature, and added salts

Element for electrophoresis containing polyacrylamide gel membrane

Abstract: An element for electrophoresis suitably employable for electrophoresis of biopolymers such as proteins, as well as for determination of base sequence of DNA, RNA, their fragments, and their derivatives, which comprises a plastic support, an adhesive layer containing a cellulose derivative, and an electrophoresis medium layer comprising an aqueous polyacrylamide gel formed by crosslinking polymerization of an acrylamide compound and a crosslinking agent in the presence of water, which are superposed in this order. The electrophoresis medium layer may contain a water-soluble polymer and agarose. The medium layer may contain a modifier such as an anionic surfactant, formamide or urea.

Methacrylic resin having improved solvent resistance

Abstract: PURPOSE:To obtain a methacrylic resin having improved solvent resistance, by copolymerizing methyl methacrylate with a (meth)acrylamide monomer. CONSTITUTION:Methyl methacrylate is copolymerized with 0.1-50wt% (meth) acrylamide shown by the formula (R1 is H, or methyl; X is H, methyl containing <=4C saturated alkoxy as a substituent group) such as (meth)acrylamide, N- methoxy-methyl(meth)acrylamide, N-propoxymethyl(meth)acrylamide, etc., to give the desired methacrylic resin.

Mechanical stabilization of large pore acrylamide gels by addition of linear polyacrylamide

Abstract: Linear polyacrylamide has been used to increase the tensile strength and stability of low percentage acrylamide gels in the range of 2.5 to 6.0 % w/v acrylamide. This added strength allows handling and staining of the gel without the excessive difficulty which is normally incurred when working in this range. Addition of up to 0.6 % w/v of linear polyacrylamide gives no pore size reduction. While addition of linear polyacrylamide to acrylamide gels using bisacrylamide as a crosslinker has a hazy appearance, the use of diallyltartardiamide as a crosslinker gives the desired clarity without loss of large pore size and improves adherence to glass walls. A further advantage of acrylamide gel matrices is that the traditional methods of silver staining can be used for detection of DNA. Thus, adding linear polyacrylamide to an acrylamide gel using diallytartardiamide as a crosslinker allows easy use of low percentage acrylamide gels for separation and detection of DNA fragments in the range of 70 to 2500 base pairs.

Anionic Polymerization of Acrylamide Initiated with the Disodium Salt of Poly(ethylene oxide)

Abstract: Anionic Polymerization of Acrylamide Initiated with the Disodium Salt of Poly(ethylene oxide)

Temporary coating compositions

Abstract: An alkali-soluble aqueous composition which is suitable for producing a temporary protective coating upon a surface which is prone to deterioration or damage, particularly a bare metal surface, comprises an aqueous medium and, dissolved or dispersed therein in salt form, an addition polymer having a weight average molecular weight of 3,000-15,000, a Tg of - 15 DEG C to +40 DEG C, and contains both carboxyl groups and hydrophilic groups selected from acrylamide, C1-8 alkyl-substituted acrylamide, vinyl pyrrolidone, vinyl pyridine and poly(oxyethylene) groups The salt is preferably formed with ammonia