Showing papers on "Carboxylic acid published in 1980"

Fluorescent Labeling of Fatty Acids with 9-Anthryldiazomethane (ADAM) for High Performance Liquid Chromatography

Abstract: A novel method for rapid and simple fluorescent labeling of carboxylic acids with 9-anthryldiazomethane (ADAM) for HPLC is described. This reagent is stable in solution and highly reactive with carboxylic acids. Esterification proceeds at room temperature without catalyst. The labeled compounds are separated using a reversed-phase system and determined with a flow-through flurometer. Picomole level of fatty acids are determined by this method.

Microelectrophoretic properties of natural surface-active organic matter in coastal seawater

Abstract: Measurements by the technique of particle electrophoresis rcvcal that different well charactcrizcd solid surfaces freshly cxposcd to seawater become covered by a tenacious film of natural surface-active organic matter which dominates their subsequent surface chemistry. The dependence of elcctrophorctic mobility (uB) on pH and metal ion concentration (pM) indicates that carboxylic acid (-COOH) and phenolic (-011) groups are the major ionizable functional groups iti the organic fihn exposed to the solution. Detailed treatment of the data on uK vs. pH and uE vs. pM allows calculation of intrinsic equilibrium constants for the dissociation of surface carboxylic acid groups and the complexation of metal ions by the organic film. The results obtained are in substantial agreement with data derived from more classical rlotentiometric titrations of marine and freshwater organic matter isolated by adsorption Or ultrafiltration methods.

Stabilized aqueous enzyme composition

Abstract: Stabilized aqueous enzyme compositions contain a stabilizing system comprising calcium ions and a low molecular weight carboxylic acid or salt, preferably a formate, preferably with a low molecular weight alcohol, and in a pH range of from about 6.5 to about 10. Most preferred is a detergent composition containing the stabilized enzymes.

Process for preparing alcohols

Abstract: An alcohol is produced in a high selectivity with a good yield from the corresponding carboxylic acid by reducing the latter with hydrogen in the presence of a rhenium catalyst in the coexistence of an organic base. An arylacetic acid, which is included in the starting carboxylic acid, can be produced in an excellent yield from the corresponding aryl aldehyde by reacting the latter with carbon monoxide and water in the presence of rhodium or its compound and hydrogen iodide.

Steroids and sex hormones. Part 262. The radical induced stannane reduction of selenoesters and selenocarbonates: A new method for the degradation of carboxylic acids to nor‐alkanes and for desoxygenation of alcohols to alkanes

Abstract: Esters of carboselenoic acids, formed from carboxylic acids by conventional methods, undergo reaction with tributyltin hydride in inert aromatic solvents, either by heating to give the corresponding aldehyde or the corresponding alkane depending on reaction temperature and the structure of the parent carboxylic acid, or by ultraviolet irradiation at ambient temperature when the aldehyde is formed predominantly in high yield. In the case of esters of α, β-unsaturated carboselenoic acids the thermal reaction leads only to the corresponding aldehyde. The above stannane reduction can also be applied to selenocarbonates of primary and secondary alcohols (prepared from the corresponding chloroformates), to give the alkane, the parent alcohol and the corresponding formate, in relative amounts depending on the reaction temperature. These reactions thus constitute preparatively useful and high-yield degradation methods compatible with the presence of many other functional groups.

Polyfluoroallyloxy compounds, their preparation and copolymers therefrom

Abstract: The reaction of a polyfluorocarbonyl compound such as a polyfluoroketone or polyfluorcarboxylic acid fluoride with fluoride ion and a polyfluoroallyl chloride, bromide or fluorosulfate produces a polyfluoroallyloxy carboxylic acid fluoride or sulfonyl fluoride, e.g., CF 2 ═CFCF 2 OCF 2 CF 2 SO 2 F. The polyfluoroallyloxy compounds copolymerize with ethylenically unsaturated monomers such as tetrafluoroethylene, chlorotrifluoroethylene or vinylidene fluoride to form polymers which are moldable, and in some cases electrically conducting or are water-wettable and dyeable.

Process for producing fluorinated polymer having ion-exchange groups

Abstract: A fluorinated copolymer having ion-exchange group is produced by copolymerizing a fluorinated ethylenic unsaturated monomer and a functional monomer having a functional group of carboxylic acid group or a group which can be converted to carboxylic acid group in an aqueous medium in the presence of a polymerization initiator source and in the presence of a specific molecular weight regulator. The specific molecular weight regulator is selected from the group consisting of aliphatic alkanes alicyclic alkanes and water soluble organic solvents and controls the molecular weight without lowering the copolymerization velocity and without lowering the stability of the aqueous latex.

Water-dispersible urethane polymers and aqueous polymer dispersions

Abstract: Aqueous dispersions of polyurethane polymers in ammonium salt form are prepared by reacting diisocyanates with a polyhydroxy, carboxylic acid to form an isocyanate-terminated prepolymer that is united with an unsaturated fatty acid ester polyol to provide carboxylic-containing, water-dispersible polyurethanes having properties exhibited by organic solvent-based, oil-modified polyurethanes. The aqueous dispersions can be formed by neutralization of "oil-modified," carboxylic group-containing, water-dispersible polyurethanes with ammonium salt-forming materials such as ammonia and amines. The aqueous dispersions are especially desirable coating compositions.

Mixed metal salts and lubricants and functional fluids containing them

Abstract: Mixed metal salts (especially zinc salts) of dialkylphosphorodithioic acids and carboxylic acids, the ratio of equivalents of the dialkylphosphorodithioic to the carboxylic acid being between about 05:1 and about 45:1, are useful in lubricants and functional fluids (such as hydraulic fluids) as antioxidants and extreme pressure agents having improved thermal stability

Anti-inflammatory/anti-pyretic salicylic acid esters with low gastric ulcerogenic activity

Abstract: The methyl and some other esters of acetylsalicylic and salicylic acids and their derivatives were found to have much lower gastric ulcerogenic activity (when assayed in the stress-sensitized rat) compared with their corresponding acids. There was little or no loss in therapeutic potencies of these salicylate esters as determined by assessment of anti-inflammatory activity (against the carrageenan-induced oedema) and antipyretic activity (against yeast-induced fever in rats. The methyl ester of acetylsalicylic acid (=AME) was almost devoid of gastric irritancy/ulcerogenicity (as observed with acetylsalicylic acid) when given orally to pigs for 10 days. AME had appreciable anti-inflammatory activity in the adjuvant-arthritis model and at high doses (200 mg/kg t.i.d.) was without the lethal effects seen with acetylsalicylic acid. Moreover, no toxic effects were seen after long-term administration of 100-1000 mg/kg/day AME for 3-4 months. The results provide further evidence for the hypothesis that the carboxylic acid moiety of salicylates is a major factor in the gastric ulcerogenic activity of these drugs. The methyl esters of these salicylates may be considered as models for the development of pro-drugs and in some cases may be therapeutic alternatives to acetylsalicylic acid or salicylate.

Macrocyclic hexacarboxylic acid. A highly selective host for uranyl ion

Abstract: Previously a macrocyclic hexaketone which effectively bound uranyl ion was prepared succesfully. Recently, two types of ligand of macrocyclic hexacarboxylic acid were prepared by symmetrically arranging six carboxylates on a macrocyclic skeleton in which the ring size was adjusted to give a cavity to accommodate uranyl ion comfortably. Three of six carboxylates seem to compose a binding site. One of the three additional carboxylic acid units in both ligands is amenable to attachment to a suitable polymer support. The other two probably act to make the microscopic environment around the metal binding site more hydrophilic as well as to decrease the entropy loss involved in the complexation. Compared with the previous hexaketone, the new macrocycle hexacarboxylic acids are capable of much more facile preparation in reasonable overall yields and are far more effective and selective for the binding of the uranyl ion. The preparation is a straightforward reaction between tetraethyl n-decane-1,1,-10,10-tetracarboxylate and diethyl ..cap alpha.., ..cap alpha..-bis(8-iodooctyl)malonate. The cyclization was achieved under high-dilution conditions, and the hexaethyl ester of macrocyclic hexacarboxylic acid was isolated through silica gel column chromatography. Alkaline hydrolysis yielded the hexacarboxylic acid. Similar procedures gave a hexacarboxylic acid containing an ether bridge. Uranyl ion is known tomore » form a stable complex with carbonate (CO/sub 3//sup 2 -/). High selectivity of these ligands to uranyl was ascertained also by competition with other metal cations such as: Na/sup +/, Mg/sup 2 +/, Ni/sup 2 +/, and Zn/sup 2 +/. These results indicate that uranyl ions can be extracted efficiently from sea water using these hexacarboxylic acid ligands which are attached to a polymer completely insoluble in water.« less

Partial characterization of undegraded oat phytochrome

Abstract: We characterized immunoaffinity-purified, undegraded oat (Avena sativa L., cv. Garry) phytochrome by several physicochemical techniques. Phytochrome, of greater than 98% purity [Hunt, R. E., & Pratt, L. H. (1979) Plant Physiol. 64, 332-336], existed in solution as a dimer of its 118 000-dalton monomers and had a full complement of the typical amino acids with about 35% nonpolar residues, 115 carboxylic acid groups per monomer, and an average of one phosphate per monomer. Although the dimer was not held together by disulfide bridges, each monomer contained three disulfide bonds and 14 reduced cysteines out of a total of 27 cysteine-half-cystine residues. Phytochrome preparations, although very pure, exhibited heterogeneity by discontinuous sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which revealed three closely spaced bands, and by nondenaturing gel electrophoresis at pH 7.0, which revealed four bands. Amino-terminal analysis indicated two residues, Lys and Ala. Manual Edman degradation yielded Leu and Ala after one round and Val and Leu after a second round. These data indicate a possible amino-terminal sequence of NH3-Lys-Ala-Leu-Val- with some monomers not having Lys.

Manufacture of ethylene from synthesis gas (D#75,673-C1)

Abstract: This invention concerns a two-step process for the preparation of ethylene from mixture of carbon monoxide and hydrogen (commonly known as synthesis gas) by reaction of said carbon monoxide/hydrogen mixtures with a carboxylic acid in the presence of one or more ruthenium catalyst complexes to form an ethyl ester of said carboxylic acid coreactant, followed by pyrolysis of said ethyl ester intermediate to ethylene.

Homogeneous catalytic hydrogenation of carboxylic acid esters to alcohols

Abstract: The homogeneous catalytic hydrogenation of activated and simple aliphatic carboxylic acid esters to their corresponding primary alcohols has been accomplished under mild conditions [90 °C; 620 kPa (gauge) of hydrogen] using a novel anionic ruthenium hydride complex.

Novel heparin derivative, method for production thereof, and method for rendering biomedical materials antithrombotic by use of the novel heparin derivative

Abstract: A heparin derivative in which at least 0.5% of the entire hydroxyl groups of heparin are in the form of an ester of the following formula ##STR1## wherein R 1 , R 2 and R 3 each represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; a method for producing aforesaid heparin derivative which comprises reacting heparin with a halide or anhydride of an unsaturated carboxylic acid of the formula ##STR2## wherein R 1 , R 2 and R 3 are the same as defined above; and a method for imparting antithrombotic activity to a biomedical material, which comprises treating that surface of the biomedical material which makes contact with the blood with actinic light in the presence of aforesaid heparin derivative.

Modification of the 5' position of purine nucleosides. 2. Synthesis and some cardiovascular properties of adenosine-5'-(N-substituted)carboxamides.

Abstract: We have shown previously that the esters of adenosine-5'-carboxylic acid (10) represent a new class of potent nontoxic coronary vasodilators. For example, the ethyl ester (12), which is active by an intraduodenal or intravenous route in dogs, causes a large increase in coronary sinus PO2 and coronary blood flow. Because of the pronounced vasoactive properties of the esters of adenosine-5'-carboxylic acid, a systematic study of the corresponding amides (14--50) was undertaken. In addition, several other analogues containing the N1-oxide function (51--52) or 2',3' substituents (3--9, 53--54) were studied.

Endiandric acid, a novel carboxylic acid from Endiandra introrsa(Lauraceae): X-ray structure determination

Abstract: X-Ray crystal structure analysis shows that endiandric acid, a constituent of the Australian tree Endiandra introrsa, has the novel racemic structure (1), (1RS,3RS,6SR,7SR,10SR,11RS,12RS,13RS)-(6-phenyltetracyclo[5.4.2.03,13010,12]trideca-4,8-dien-11-yl]acetic acid.

Co-oligomerization of butadiene and carbon dioxide catalysed by tertiary phosphine–palladium complexes

Abstract: Tertiary phosphine–palladium complexes catalyse the co-oligomerization reaction of butadiene and carbon dioxide under mild conditions of temperature and pressure (70 °C, 100 atm) to yield (E)-2-ethylidenehept-6-en-5-olide (2) and octadienyl esters of (E)-2-ethylidenehepta-4,6-dienoic acid (3b, c) and of 2-vinylhepta-4,6-dienoic acid (4b, c). At higher temperature (90 °C) esters (3b, c) yield octa-1,3,7-triene and (E)-2-ethylidenehepta-4,6-dienoic acid through an oxidative addition of the allyl carbon–oxygen bond to a palladium(0) species. Subsequent reactions of the carboxylic acid in the presence of [PdLn](L = tertiary phosphine) complexes yield (E)-2-ethylidenehept-5-en-4-olide (1) and 2-ethylhepta-2,4-dien-4-olide (5).

Resin compositions comprising polyphenylene oxide, polyamide and a compound improving the impact resistance

Abstract: A resiin composition comprising a resin (1) comprising 5 to 95% by weight of a polyphenylene oxide and 95 to 5% by weight of a polyamide and (2) 0.01 to30 parts by weight of (A) a liquid diene polymer, (B) an epoxy compound or (C) a compound having in the molecule both (a) an ethylenic carbon-carbon double bond or a carbon-carbon triple bond and (b) a carboxylic acid, acid anhydride, acid amide, imido, carboxylic acid ester, amino

Structure--activity relationships in a series of novel 3,4-dihydro-4-oxopyrimido[4,5-b]quinoline-2-carboxylic acid antiallergy agents.

Abstract: A series of more than 50 new 3,4-dihydro-4-oxopyrimido[4,5-b]quinoline-2-carboxylic acid derivatives and related compounds with substituent variations at the 2, 3, and 5--9 positions was prepared and evaluated for antiallergy activity using the rat PCA assay. These compounds were obtained by the condensation of the appropriately substituted 2-aminoquinoline-3-carboxamides with dialkyl oxalates, followed by further chemical transformations. More than two-thirds of the compounds prepared exhibited intravenous activity ranging from 1 to 400 times disodium cromoglycate (DSCG). Structure--activity data suggest that the presence of a carboxylic acid moiety at the 2 position affords optimal potency and that esters are preferred for good oral absorption. Best oral activity, with ED50 values ranging from 0.3 to 3.0 mg/kg, was displayed by ethyl esters with methoxy and/or ethoxy groups at the 7 and 8 positions.

Stabilized aqueous enzyme composition

Abstract: Stabilized aqueous enzyme compositions contain a stabilizing system comprising calcium ions and a low molecular weight carboxylic acid or salt, preferably a formate, preferably with a low molecular weight alcohol, and in a pH range of from about 6.5 to about 10. Most preferred is a detergent composition containing the stabilized enzymes.

Insulin compsns. for admin via mucosa - contg. selected acids to increase absorption pref. also contg. a surfactant and a protease inhibitor

Abstract: Insulin prepns. comprise insulin, a carrier for absorption via mucous membranes, and 0.01-0.5 wt.% of >=1 selected from (a) 1-6C alkanoic acid, (b) lower hydroxy carboxylic acid, (c) inorganic acids selected from HCl, H3PO4, HN3, phosphotungstic acid and HClO4, (d) benzoic, phthalic and pyromellitic acids, (e) monochloro-, dichloro-, trichloro- and sulpho-acetic acids, (f) acrylic and maleic acids, and (g) pyruvic, furoic and picric acids. The carrier is pref. a suppository base. Pref. acids are 1-5C alkanoic acids (esp. acetic), tartaric acid, glycolic acid, HCl, HNO3 and monochloroacetic acid. The prepns. can also contain a surfactant and a protease inhibitor. They are pref. produced by dissolving insulin in an aq. soln. of the acid and incorporating the soln. into the carrier (esp. molten suppository base). The prepns. are esp. useful for rectal, intravaginal or sublingual admin. giving large reductions in blood sugar levels at low insulin concns.

Siloxane-modified epoxy resin compositions

Abstract: Compositions containing siloxane-modified epoxy resins, epoxy, methacryl, or amino organofunctional alkoxysilicon compound and conventional epoxy curing agents are described which have improved resistance to degradation of both electrical properties and adhesion when exposed to moisture or boiling water. The compositions consist essentially of (A) siloxane-modified epoxy resin, (B) an organofunctional alkoxysilicon compound such as γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, or γ-glycidoxypropyltrimethoxysilane, and (C) curing agents such as carboxylic acid anhydrides.

Peptide affinity labels for thrombin and other trypsin-like proteases

Abstract: A peptide affinity label of the formula (I): ##STR1## wherein X is a radical capable of acting as a leaving group in a nucleophilic substitution reaction; A is an aromatic amino acid residue; B is H, or a C 1 -C 4 alkyl group, or aryl; Y is selected from the group consisting of hydrogen, aroyl, C 1 -C 6 acyl, and Q--(A)-- n , wherein Q=hydrogen, aroyl, or C 1 -C 6 acyl, n=1-10, A is an amino acid residue selected from the aliphatic, hydroxy-containing, carboxylic acid group, and amide-thereof-containing, aromatic, sulfur-containing and imino-containing amino acids; and wherein J is selected from the group consisting of --CH 2 --, --CH 2 --CH 2 --,--CH 2 --CH 2 --CH 2 --, --CH═CH-- and --CH(OH)--CH 2 . The affinity label is useful for irreversibly inactivating thrombin and trypsin-like enzymes and may be used as a potential anticlotting agent.

Association of 6-oxo-piperidine-2-carboxylic acid with penicillin v

Abstract: Analysis of a 13C NMR spectrum of a concentrated broth from Penicillium chrysogenum fermentation revealed the presence of penicillin V and 6-oxo-piperidine-2-carboxylic acid (1) as the principal constituents. The latter lactam, identical to an authentic sample prepared by the cyclization of α-aminoadipic acid was present to the extent of 28mol% of penicillin V. The lactam isolated from the broth was nearly racemic, having a slight excess of the L-isomer. This isolation provides further evidence regarding the biosynthetic precursors of the hydrophobic penicillins.

Photopolymerized hydrophilic interpolymers of unsaturated carboxylic acid and esters

Abstract: Highly water absorbent films and fibers are prepared by photopolymerizing an alkaline metal salt of acrylic acid, at least one alkyl acrylate or methacrylate wherein the alkyl group contains 10 to 30 carbon atoms, at least one alkyl acrylate or methacrylate wherein the alkyl group contains 1 to 4 carbon atoms and a photoinitiator. The resulting interpolymers are particularly useful in the preparation of highly absorbent personal hygiene and care products.