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At least 19 recordsLinked to original sources
PubMed1977

The structure and function of ribonuclease T1. XXIII. Inactivation of ribonuclease T1 by reversible blocking of amino groups with cis-aconitic anhydride and related dicarboxylic acid anhydrides.

Ribonuclease T1 [EC 3.1.4.8] was inactivated rapidly by treatment at pH 8.0 and 0 degrees C with cis-aconitic anhydride and related dicabroxylic acid anhydrides, including citraconic, maleic, and succinic anhydrides. Under reaction conditions used, roughly 90% inactivation occurred within 30 min. Analyses of the inactivated enzymes indicated that the reaction took place fairly specifically at the alpha-amino group of the N-terminal alanine and the epsilon-amino group of lysine-41. Upon incubation of these inactivated enzymes at pH 3.6 and 37 degreeC, the activity was regenerated to various extents, depending on the nature of the introduced acyl groups. Under these conditions, the enzyme modified with cis-aconitc anhydride or citraconic anhydride recovered much of the origninal activity after 48 h whereas the enzyme modified with maleic anhydride recovered its activity only partially. Practically no activity was regenerated in the case of the enzyme modified with succinic anhydride under these conditions. The inactivation appears to be due mainly to the effect of the carboxyl group introduced at the epsilon-amino group of lysine-41. The results suggest the usefulness of cis-aconitic anhydride as a reversible blocking reagent for amino groups in proteins.

Aconitic Acid↗
PubMed1977

Asthma due to inhaled chemical agents--epoxy resin systems containing phthalic acid anhydride, trimellitic acid anhydride and triethylene tetramine.

Six workers with a diagnosis of occupational asthma and one with chronic bronchitis were examined for sensitivity to epoxy resin systems and certain of their components. In six cases the chemical agent responsible for their symptoms was identified by careful inhalation challenge testing, simulating their exposure at work and thus providing a precise aetiological diagnosis. In one worker asthma followed exposure to triethylene tetramine fume; four were sensitive to acid anhydrides, three to phthalic acid anhydride as a fume or powder and one to trimellitic anhydride. On worker thought to be sensitive to toluene di-isocyanate gave negative reactions to this and positive reactions to a phthalic acid anhydride epoxy resin and another thought to have asthma from acid anhydride fumes was found to be sensitive only to toluene di-isocyanate. Immediate, non-immediate or combined asthmatic reactions were elicited.

Adult↗
PubMed1977

GC-MS measurement of deuterium in succinic anhydride and TMS-succinate. An isotope memory effect with succinic anhydride.

Direct GC-MS of succinic and glutaric anhydrides has been investigated, and shown to be feasible. In the GC-MS determination of deuterium in succinic anhydride, an isotope memory effect was observed, shown to be due to strong adsorption of solute onto the column. This phenomenon was investigated, together with possible methods for its suppression. Succinate TMS ester also was found to be a suitable derivative for direct GC-MS of deutero-succinic acid.

Anhydrides↗
PubMed1978

Human antihapten antibodies in trimellitic anhydride inhalation reactions. Immunoglobulin classes of anti-trimellitic anhydride antibodies and hapten inhibition studies.

Inhalational exposure to trimellitic anhydride (TMA) produces an immediate-type asthmatic or a late respiratory systemic syndrome in certain workers after a latent period of work exposure. TMA has been found to react with proteins to produce a hapten-protein complex (trimellitate [TM] protein) or become hydrolyzed in aqueous, alkaline solutions to produce a salt, NaTM. Using a solid-phase radioimmunoassay technique, antibodies of different Ig classes were detected against TM-protein conjugates. IgE antibody was detected in three of five workers with asthma. IgG and IgA antibodies were detected in most exposed workers but higher levels of antibody were found in symptomatic workers even after long periods without direct TMA exposure. IgM antibody activity against TM-human serum albumin (TM-HSA) was detected but did not differentiate symptomatic from asymptomatic workers. NaTM served as a hapten for study because it does not react with proteins to form a hapten-protein complex as TMA does. The NaTM only partially inhibited IgG antibody activity against TM-HSA and much smaller amounts of TM-HSA than of NaTM were required to neutralize IgG antibody. A similar result was found with TM-ovalbumin. The latter results suggest that some IgG antibody is directed against a TM-protein moiety, probably a TM-amino acid determinant. In contrast to IgG, marked inhibition by NaTM of IgA and IgM antibody against TM-HSA was found in the sera studied.

Anhydrides↗
PubMed1975

A new inhibitor of coupled oxidative phosphorylation, 5-hydroxynaphthalenedicarboxylic anhydride, a derivative of a carcinogenic polynuclear hydrocarbon.

5-Hydroxy-1,2-naphthalenedicarboxylic anhydride is closely related to its precursor dibasic acid which is a metabolite of the carcinogenic polynuclear hydrocarbon dibenz[a,h]anthracene. The anhydride inhibited respiration of coupled mitochondria. This inhibition was relieved by 2,4-dinitrophenol. Several mitochondrial volume change processes energized by ATP were also inhibited by the anhydride. Both the mitochondrial ATPase activity induced by 2,4-dinitrophenol and the ATPase activity of submitochondrial particles induced by magnesium ion were inhibited by the anhydride. The spectrum of inhibitory activity was not associated with acetic anhydride, succinic anhydride, or phthalic anhydride. The data indicate that 5-hydroxy-1,2-naphthalenedicarboxylic anhydride inhibits the machinery of oxidative phosphorylation in a manner similar to rutamycin. 5-Hydroxy-1,2-naphthalenedicarboxylic anhydride is the first molecule derived from a carcinogen with such inhibitory properties.

Adenosine Triphosphatases↗
PubMed1976

The immediate uptake of potassium ion by mitochondria requiring gramicidin and 2,2-dimethylsuccinic anhydride.

The addition of 2,2-dimethylsuccinic anhydride to mitochondrial suspensions fortified with gramicidin and potassium ion but without any permeant anion caused an immediate and rapid increase in volume (as indicated by absorbance change at 520 nm) and the uptake of potassium ion (as indicated by a cation-specific electrode). The phenomena was not inhibited by rutamycin but was inhibited by either rotenone, antimycin or 2,4-dinitrophenol. Rotenone inhibition was relieved by succinate thus one of the requirements of the process was energy derived from endogenous substrates. Potassium ion could be replaced by rubidium and cesium ions but not by lithium or sodium ions. Since 2,2-dimethylsuccinate could not replace the anhydride and was not a permeant anion there must also be a requirement for the anhydride bond. The action of the anhydride on the mitochondria must be direct. Only closely related anhydrides were capable of engendering the effect of a highly effective permeant anion.

Adenosine Triphosphate↗
PubMed1975

Solvolytic reactions of cyclic anhydrides in anhydrous acetic acid.

The reversible reactions of several cyclic anhydrides with acetic acid to form acetic anhydride and the corresponding dicarboxylic acid, catalyzed by perchloric acid at 25degree, were studied. The equilibrium constants, calculated from spectral data, were 4.85 X 10-4, 1.08 X 10-1, and 4.6 X 10-1 M for succinic, trans-1,2-cyclohexanedicarboxylic, and glutaric anhydrides, respectively. Maleic, phthalic, and cis-1,2-cyclohexanedicarboxylic anhydrides did not undergo any detectable reaction with acetic acid under these conditions, suggesting still higher stability. The reverse rate constants were found to be relatively independent of the structure of the attacking diacid, while the forward rate constants were found to parrallel the equilibrium constants. The rate-determining step for the forward reaction appears to be the breakdown of the tetrahedral intermediate formed by the attack of an acetic acid molecule on the protonated cyclic anhydride.

Acetates↗
PubMed1975

Acylation of phenol by cyclic and acyclic anhydrides in anhydrous acetic acid.

Acylation of phenol with succinic, glutaric, trans-1,2-cyclohexanedicarboxylic, maleic, phthalic, and cis-1,2-cyclohexanedicarboxylic anhydrides in anhydrous acetic acid generally resulted in phenyl acetate as the major product. The formation of phenyl acetate as the major reaction product could be rationalized as being due to the reactivity of the cyclic anhydrides with acetic acid to form acetic anhydride as well as the greater reactivity of phenol with formed acetic anhydride than with the cyclic anhydride.

Acetates↗
PubMed1978

Heme sulfuric anhydrides as soybean leghemoglobin structure probes.

Mesoheme monosulfuric anhydride reacts at three distinct sites in soybean apoleghemoglobin a, at lysine-6, lysine-19 and lysine-57, the last one being the major site of reaction. The heme peptides obtained from thermolytic and pronase hydrolysates of the anhydride-leghemoglobin a were purified and correlated with the known amino acid sequence of the protein. Mesoheme bissulfuric anhydride also reacts with soybean apoleghemoglobin a giving a complex mixture of hemepeptides after hydrolysis with pronase. The visible spectrum of anhydride leghemoglobin is that of low spin heme. This suggests that anhydride leghemoglobin has a conformation with a covalent attachment via propionic acid side chain to lysine-57 and the sixth coordination position of the heme iron occupied by the distal histidine at position 61. Native leghemoglobin is assumed to exist in a similar type of configuration at low temperature, but with the heme propionate side chain being involved in a salt bridge with lysine-57.

Affinity Labels↗
PubMed1979

Mixed anhydrides of nucleotides and mesitylenecarboxylic acid as new specific inhibitors of mitochondrial adenosien triphosphatase.

Mixed anhydrides of nucleoside triphosphates and mesitylenecarboxylic acid inhibit soluble mitochondrial ATPase (adenosine triphosphatase), but do not inhibit ATPase of submitochondrial particles. Inhibition of soluble mitochondrial ATPase by the mixed anhydride of epsilon-ATP and mesitylenecarboxylic acid is followed by the covalent binding of one nucleotide residue to a molecule of the protein. It is suggested that this covalent binding occurs in the catalytic site of the mitochondrial ATPase. The mixed anhydride of ADP and mesitylenecarboxylic acid inhibits the ATPase activity of submitochondrial particles and has no effect on the activity of soluble mitochondrial ATPase. After separation of the submitochondrial particles from the mixed anhydride of ADP and mesitylenecarboxylic acid, their ATPase activity is restored to its original value (half-time of reactivation 3--4 min). Incubation of submitochondrial particles or soluble mitochondrial ATPase with the mixed anhydride of ADP and mesitylenecarboxylic acid results in AMP formation.

Adenosine Triphosphatases↗
PubMed1975

Radiolabeling of proteins and viruses in vitro by acetylation with radioactive acetic anhydride.

We describe a convenient, rapid, and reproducible method for labeling proteins in vitro by acetylation with [3H] or [14-C]acetic anhydride dissolved in small amounts of anhydrous dioxane. The reaction is carried out at neutral pH and does not require the use of detergents, water-immiscible organic solvents, oxidizing, or reducing agents. Thus undesirable solvent-induced alterations in protein structure and biological activity are minimized. A method for calculating the specific activity of the protein and the efficiency of acetylation at known concentrations of protein and acetic anhydride is presented. Radioacetylated proteins were shown to be suitable for use as molecular weight calibration standards and as protein markers in polyacrylamide gel electrophoresis, gel filtration, and enzyme studies. Acetic anhydride was used to label intact oncornaviruses, which consist of a complex ribonucleo-protein core within a lipid envelope. Some of the viral lipid and all of the viral proteins, including the internal ones, were labeled without detectable alterations in viral morphology or buoyant density. This result suggests that acetic anhydride, evidently by virtue of its small size and neutral charge, penetrates freely throughout the viral membrane and core structures. The reactivity of RNA with acetic anhydride was less than 1% that of protein under similar reaction conditions.

Acetates↗
PubMed1977

Recording pH method of characterizing composition and monitoring dissolution profile of an anhydride-acid copolymer and its salt derivatives.

A sensitive potentiometric monitoring method was developed that permits the continuous measurement of the disolution profiles of methyl vinyl ether-maleic anhydride-acid copolymers and salt derivatives. Three distinct rate periods were observed in the dissolution rate of the anhydride copolymer, expressed as percent anhydride dissolved, was independent of sample weight over the weight range studied. The acid form of the copolymer showed only one dissolution rate period, with dissolution being very rapid. The rapid initial pH decrease observed during the first stage of dissolution for a series of anhydride-acid copolymer powder samples correlated closely with the anhydride-acid ratio, permitting chemical characterization of the copolymer functionality simultaneously with the analysis of dissolution profiles. Similarly, the extent of copolymer alkaline salt conversion was inversely proportional to the initial maximum pH increase observed during the first stage of dissolution of these salts. Mechanisms of dissolution of copolymer powder materials are discussed and compared to the dissolution of compressed disks and films reported previously.

Hydrogen-Ion Concentration↗
PubMed1975

Preparation, properties and metabolism of retinoic acid anhydride.

A new analogue of vitamin A, viz., retinoic acid anhydride was prepared, for the first time, by the action of thionyl chloride on retinoic acid in benzene containing pyridine. The amhydride was charcterised by its chromatographic properties, elemental analysis, ultraviolet absorption, infrared and nuclear magnetic resonance spectral characteristics. The compound could be readily hydrolysed to retinoic acid both by acid and alkali treatments and reduced by lithium aluminium hydride to vitamin A alcohol (retinol). The spectral changes with antimony trichloride reagent were similar to those observed for retinoic acid. The metabolism of retinoic acid anhydride was found to be similar to that of retinoic acic. When administered either orally or intraperitoneally, the compound promotes growth in vitamin A-deficient rats. Time-course experiments revealed that retinoic acid anhydride is converted into retinoic acid by non-enzymatic hydrolysis and thereby exerts its biological activity. The biopotency of the anhydride was found to be nearly the same as that of the acid. A new method of preparing esters of retinoic acid employing retinoic acid anhydride as an intermediate, has been described.

Absorption↗
PubMed1979

Formation of stable anhydrides from CoA transferase and hydroxamic acids.

Acetohydroxamic acid reacts with the enzyme-CoA form of succinyl-CoA:3-ketoacid coenzyme A transferase to give an inactive product with a rate constant of 860 M-1 min-1 at pH 8.1, 25 degrees C. The reaction is reversible in the presence of coenzyme A and has an equilibrium constant of 0.040. The product is an anhydride that is an analog of the intermediate that has been postulated in the normal catalytic pathway; it is inactive because coenzyme A does not react with the acyl group of the hydroxamic acid. The equilibrium constant for formation of the anhydride from the thil ester of enzyme and methyl 3-mercaptopropionate is 75 times larger than the equilibrium constant of 2.2 for the formation of N,O-diacetylhydroxylamine from acetohydroxamic acid and acetyl-CoA. This shows that the enzyme stabilizes the anhydride at the active site by at least -2.6 kcal mol-1. Succinomonohydroxamic acid reacts with enzyme-CoA as both a substrate and an inactivator, with relative rate constants of 25:1. The inactivation is irreversible, indicating that the enzyme provides a larger stabilization of at least -5.9 kcal mol-1 for the anhydride of an analog of the specific substrate, succinate. The results are consistent with the hypothesis that the enzyme stabilizes an anhydride that is formed at the active site during turnover of normal substrates through a stepwise reaction mechanism.

Acetoacetates↗
PubMed1979

Sampling and analysis of acetic anhydride in air.

This paper describes the development of a new method for monitoring acetic anhydride in the presence of acetic acid in the occupational environment. The method consisted of collecting airborne acetic anhydride on a solid sorbent, desorbing it with acetone and analyzing it by gas chromatography. During the development of this method various parameters such as selection of column, selection of solid sorbent, selection of desorber solvent, effects of humidity, flow rate, total sample volume, desorption efficiency, and shelf-life of samples were studied. Interference from methyl acetate, water, formic acid, and acetic acid was also tested with the determination of acetic anhydride.

Acetates↗
PubMed1975

Femtomole sensitive radioimmunoassay for cyclic AMP and cyclic GMP after 2'0 acetylation by acetic anhydride in aqueous solution.

The sensitivity of radioimmunoassays for cyclic AMP and cyclic GMP has been markedly improved to readily detect femtomole (10-15) amounts in tissue extracts by acetylating the cyclic nucleotides at the 2'0 position with acetic anhydride. Acetylation of cyclic nucleotides by acetic anhydride in aqueous solution proceeds more rapidly than the hydrolysis of acetic anhydride to acetic acid thus yielding 100% acetylated cyclic nucleotide. 2'0 substituted cyclic nucleotides have greater affinity for the antibody than the parent cyclic nucleotides because the antibody has been made to a protein conjugate coupled at the 2'0 position. This simple acetylation technique makes it possible to measure cyclic AMP and cyclic GMP in minute quantities of tissue without purification or concentration of the sample.

Acetates↗
PubMed1979

Isolation of salicylsalicylic acid, acetylsalicylsalicylic acid, and acetylsalicylic anhydride from aspirin tablets by extraction and high-pressure liquid chromatography.

Aspirin and four salicylate impurities of aspirin (salicylic acid, acetylsalicylsalicylic acid, acetylsalicylic anhydride, and salicylsalicylic acid) were resolved by silica gell TLC and by high-pressure liquid chromatography (HPLC) on a reversed-phase C18 column. Care was necessary in the choice of a column because of similar column failed to resolve these five compounds. Salicylsalicylic acid was isolated from aspirin tablets by extraction followed by reversed-phase C18 HPLC. The structure of this compound was confirmed by comparison with an authentic sample of salicylsalicylic acid by HPLC, TLC, IR and UV spectrophotometry, and mass spectrometry. Two other compounds, acetylsalicylic anhydride and acetylsalicylsalicylic acid, which had been previously identified by chromatography as impurities in aspirin, were isolated and further characterized.

Anhydrides↗