Showing papers on "Carboxylic acid published in 1982"

9-Thiomaytansinoids and their pharmaceutical compositions and use

Abstract: This invention relates to 9-thiomaytansinoid compounds represented by the formula ##STR1## wherein R is hydrogen or acyl derived from a carboxylic acid, X is chlorine or hydrogen, Y is hydrogen, lower alkylsulfonyl, or alkyl or aralkyl which are unsubstituted or substituted, and methods of producing the same. The compounds are useful as antitumor, antiprotozoal and antifungal agents.

Structure and dynamics of intramolecular hydrogen bonds in carboxylic acid dimers: A solid state NMR study

Abstract: Direct evidence for dynamic intramolecular double proton exchange in carboxylic acid dimers in the solid is obtained from NMR measurements. For the p‐toluic acid dimer, an asymmetric double minimum potential with an energy difference ΔG = 1.0 kJ/mol and an activation energy of Ea = 4.8 kJ/mol between the two tautomeric forms is found. The equilibrium position of the carboxylic proton pair at low temperature is derived from the corresponding dipolar coupling tensor. The importance of double proton tunneling at low temperature is discussed.

Process for hydrogenolysis of carboxylic acid esters

Abstract: A process for effecting hydrogenolysis of a carboxylic acid ester comprising contacting a vaporous mixture containing the ester and hydrogen with a catalyst comprising a reduced mixture of copper oxide and zinc oxide at a temperature in the range of from about 75 C up to about 300 C and at a pressure in the range of from about 0.1 kg/cm absolute (about 9.8 kPa) up to about 100 kg/cm absolute (9813 kPa).

Composition for oral cavity

Abstract: The purpose of the present invention is to provide a composition for oral cavity that shows a high stability of a nonionic antimicrobial agent and gives an excellent feeling in use. Provided is a composition for oral cavity which contains: component (A) comprising one or more kinds of lactam compounds selected from the group consisting of a pyrrolidone carboxylic acid, a 6-oxo-2-piperidine carboxylic acid, 3-(2-oxo-1-azepanyl) propanoic acid and salts thereof; and component (B) comprising a nonionic antimicrobial agent. It is preferred that component (A) is a pyrrolidone carboxylic acid and/or a salt thereof. It is preferred that component (B) is isopropylmethylphenol, thymol, triclosan and/or hinokitiol.

Selective Dimerization of Aldehydes to Esters Catalyzed by Hydridoruthenium Complexes

Abstract: RuH2(PPh3)4 and other hydridoruthenium complexes catalyze selective conversion of aldehydes into esters in high yields. The method is applicable to most aliphatic aldehydes as well as to aromatic aldehydes. The purity of aldehydes is critical for achieving high conversions, since the presence of carboxylic acid completely inhibits the reaction and alcohol and triphenylphosphine reduce the yields of esters. RuH2(PPh3)4 is converted into Ru(CO)3(PPh3)2 through the reaction indicating the occurrence of decarbonylation of aldehyde. A mechanism involving the acyl-H cleavage of aldehyde is proposed to account for the catalysis and formation of compounds accompanying the reaction. The mechanism is compared with an alternative one which comprises of consecutive insertions of two aldehyde molecules into Ru–H bond followed by β-hydrogen abstraction from an alkoxo intermediate formed. Addition of water changes the reaction course to give carboxylato carbonyl complexes Ru(OCOR)2(CO)m(PPh3)2 (m=1 and 2). Cross esterif...

Process for producing olefin polymers or copolymers and catalyst components used therefor

Abstract: A process for producing olefin polymers or copolymers which comprises polymerizing olefins or copolymerizing olefins with each other or with dienes in the presence of a catalyst system composed of the following components (A), (B) and (C): (A) a solid titanium catalyst component containing magnesium, titanium, halogen and an ester selected from the group consisting of esters of polycarboxylic acids and esters of polyhydroxy compounds, said catalyst component being obtained by contacting a liquid hydrocarbon solution of (i) a magnesium compound with (ii) a titanium compound in the liquid state to form a solid product or first preparing a liquid hydrocarbon solution of the magnesium compound (i) and the titanium compound (ii) and then forming a solid product therefrom, said reaction of forming the solid product being carried out in the presence of (D) at least one electron donor selected form the group consisting of monocarboxylic acid esters, aliphatic carboxylic acids, carboxylic acid anhydrides, ketones, aliphatic ethers, aliphatic carbonates, alkoxy group-containing alcohols, aryloxy group-containing alcohols, organic silicon compounds having an Si-O-C bond and organic phosphorus compounds having a P-O-C bond, and during or after the formation of the solid product, contacting the solid product with (E) and ester selected from the group consisting of esters of polycarboxylic acids and esters of polyhydroxy compounds, (B) and organometallic compound of a metal selected from the group consisting of metals of Groups I to III of the periodic table, and (C) and organic silicon compound having an Si-O-Cbond or Si-N-C bond;and a solid titanium catalyst component used therefor.

Functionalization of polymeric organolithium compounds. Carbonation

Abstract: The carbonation reactions of polymeric organolithium compounds with high purity, gaseous carbon dioxide have been investigated in benzene and benzene/tetrahydrofuran (75/25) solutions. The polymers investigated were poly(styryl)lithium, poly(isoprenyl)lithium, and poly(styrene-b-isoprenyl)lithium. In Benzene solution the products are a mixture of the carboxylic acid and the ketone (dimer). No tertiary alcohol product (trimer) was observed. In benzene/tetrahydrofuran solution, the quantitative carboxylation of chain ends was observed.

Syntheses of biologically active ubiquinone derivatives.

Abstract: Various 6-alkylubiquinone or 6-(omega-haloalkyl)ubiquinone derivatives were synthesized through a radical coupling reaction between alkanoyl or omega-haloalkanoyl peroxides and ubiquinone 0. The latter was synthesized from 2-methoxy-4-methylphenol via nitration, methylation, reduction, and oxidation by modifications of the reported methods. 6-(omega-Haloalkyl)ubiquinones were converted to 6-(omega-hydroxyalkyl)ubiquinones by a mercuric-assisted solvolysis technique. The 6-(omega-hydroxyalkyl)ubiquinones were then esterified with carboxylic acid anhydrides or carboxylic acid bearing reporting groups, such as a photoaffinity label, N-(4-azido-2-nitrophenyl)-beta-alanine, or a spin-label, 3-carboxy-2,2,5,5-tetramethyl-3-pyrrolinyl-1-oxy. The esterification was catalyzed by dicyclohexylcarbodiimide and pyridine, and the esters were purified by preparative silica gel thin-layer chromatography, developed by 3% ethanol in benzene. The spectral properties and biological functions of the synthesized ubiquinone derivatives were studied. The biological function of the synthesized compounds was followed by the ability to serve as an electron acceptor, donor, or mediator in the isolated mitochondrial electron transfer complexes of succinate-Q reductase, ubiquinol-cytochrome c reductase, and succinate-cytochrome c reductase, respectively. The concentration effect of these ubiquinone derivatives on the electron transfer reaction was compared with that of ubiquinone 10. The study of the inhibitory effect of synthesized arylazidoubiquinone on succinate-cytochrome c reductase after photolysis confirmed the existence of specific Q-binding proteins in this segment of the respiratory chain. The specific interaction between ubiquinone and protein has also gained support from the immobilization of the spin-label of a synthesized spin-labeled ubiquinone derivative.

Direct separation of amino enantiomers by high performance ligand exchange chromatography on chemically bonded chiral phases

Abstract: Various chiral chemically bonded stationary phases for the separation of amino acid enantiomers by high performance ligand exchange chromatography are described. The phases were synthesized by treating silica gel with 3-glycidoxypropyltrimethoxysilane and bonding L-amino acids such as L-azetidine carboxylic acid, L-pipecolic acid or L-phenylalanine to the product. The best results were obtained with L-pipecolic acid as a fixed ligand. Nearly all common amino acid enantiomers could be separated.

ML-236B Derivatives

Abstract: A compound of formula (I): ##STR1## (called 6-methoxy-IsoML-236B lactone) and its corresponding free hydroxy-carboxylic acid and salts and esters of said acid may be prepared by the enzymatic alkoxylation of an ML-236B compound, preferably using a microorganism of the genus Syncephalastrum, Absidia or Cunninghamella, eg Absidia coerulea, or a cell-free enzyme-containing extract from said microorganism If desired, the lactone or carboxylic acid may be converted by conventional salification or esterification techniques to the desired salt or ester These compounds have the ability to inhibit the biosynthesis of cholesterol and are thus of value in the treatment of hypercholesteraemia, for which purpose they may be formulated as compositions in admixture with conventional pharmaceutical carriers or diluents

Process for preparing 3-hydroxy-ml-236b derivatives known as m-4 and m-4'

Abstract: Compounds of formula (I): ##STR1## (wherein OH represents OH or OH), that is to say M-4 carboxylic acid and M-4' carboxylic acid, as well as pharmaceutically acceptable salts and esters thereof and the corresponding ring-closed lactones may be prepared by contacting an ML-236B compound with a microorganism of the genus Nocardia or a cell-free, enzyme-containing extract thereof and then, if necessary, subjecting the resulting product to one or more of the following reactions: hydrolysis, salification, esterification and lactonisation. The resulting M-4 and M-4' derivatives have the ability to inhibit the biosynthesis of cholesterol and are therefore of value in the therapy and/or prophylaxis of hyperlipaemia and arteriosclerosis.

Coupling of polyorganophosphazenes to carboxylic acid

Abstract: A carboxylated phosphazene polymer, comprising a phosphazene polymer backbone covalently coupled to a carboxylate-containing compound through a divalent organic radical attached at one end to the carboxylate by an amide bond formed at a primary aliphatic amino group of the radical and at the other end to a phosphorous of the phosphazene backbone.

Synthesis and characterization of silica gel ion-exchanger bearing 2-amino-1-cyclopentene-1-dithio-carboxylic acid (ACDA) as chelating compound

Abstract: A method is described for the preparation of ACDA chemically bonded to silica gel as well as ACDA filter papers and their ion-exchange properties with metal ions have been investigated. The parameters such as effect of pH and effect of time on the extraction efficiency of metal ions using SG-ACDA were studied. The SG-ACDA show greater affinity for Ag(I), Hg(II) and Pd(II) (exchange capacities about 1 mmol/g) compared to other metal ions like Cu(II), Ni(II), Cd(II), Zn(II), Pt(IV) (0.2–0.6 mmol/g). The kinetics of ACDA functionalised silica-metal interactions have been found to be very rapid, the time for 90% uptake being 1–5 min.

Liquid detergent composition

Abstract: A liquid detergent composition comprises: (A) 5-25 wt % of an ammonium alkyl sulfate of the formula (1): Rsub1 OSOsub3 NHsub4 (1) wherein R 1 is a straight-chain or branched, saturated hydrocarbon group having 8-18 carbon atoms on the average, (B) 005-5 wt % of an alkylenediaminecarboxylic acid derivative of the formula (2): ##STR1## wherein R 2 is an alkylene group having 2-3 carbon atoms, A, B, C and D may be the same or different and each is ##STR2## or hydrogen, R 3 is C n H 2n (n being 1 or 2), or ##STR3## and Y is hydrogen or a cation, with the proviso that the number of hydrogen atoms contained in A, B, C and D is at most 2, and (C) 01 to 5 wt % of a carboxylic acid, a salt of the carboxylic acid, an amino acid or a salt of the amino acid

Tetronomycin, a novel polyether of unusual structure.

Abstract: Tetronomycin, C34H50O8, isolated from a strain of Streptomyces sp. nov. represents a novel polycyclic ionophore polyether. The crystal structure and absolute configuration were established by X-ray analysis of the mono-O-acetyltetronomycin silver salt. Tetronomycin is the first metabolic polyether which contains a tetronic acid moiety instead of the essential carboxylic acid function. A trisubstituted cyclohexane ring and an interesting molecular conformation of the silver salt represent additional unique structural features. Extensive NMR-studies enabled the assignment of chemical shifts and the correlation of the proton and carbon signals. Tetronomycin exhibits activity against Gram-positive bacteria.

Mixture analysis by triple-quadrupole mass spectrometry: metabolic profiling of urinary carboxylic acids.

Abstract: In this new method for profiling urinary carboxylic acids, lyophilized urine samples are analyzed directly with a triple-quadrupole mass spectrometer. Extraction, derivatization, and lengthy gas-chromatographic separation procedures are obviated by this approach. Total sample-preparation, instrument, and data-analysis time per sample is about 15 min. More than 100 different organic acids can be detected in a typical urine sample. All components of the solid urine residue are volatilized into the ion source of the mass spectrometer and converted to (M-1)- ions by reaction with OH- under chemical ionization conditions. Quadrupole 1 is set to transmit ions of a particular m/z ratio, which in turn collide with molecular nitrogen in quadrupole 2 and dissociate to smaller charged fragments. Carboxylic acid (M-1)- ions uniquely lose either CO2 (44 atomic mass units) or both H2O and CO2 (62 atomic mass units). Quadrupole 3 is set to pass only ions that have lost either 44 or 62 atomic mass units. Accordingly, the instrument specifically detects carboxylic acids in the urine matrix and no other components. Direct analysis of polyethylene glycols and their acidic metabolites in urine and serum of a burn patient treated with an antimicrobial cream having a polyethylene glycol base is also discribed.

Studies on chitin, 8. Modification reaction of chitin in highly swollen state with aromatic cyclic carboxylic acid anhydrides

Abstract: Reaction of partially deacetylated chitin with aromatic cyclic carboxylic acid anhydrides such as phthalic anhydride, trimellitic anhydride, and pyromellitic dianhydride was successfully carried out under almost homogeneous conditions in organic aprotic solvents using highly swollen precipitates of water-soluble chitin with about 50% deacetylation. The resulting amic acid-chitins were converted into the corresponding imide-chitins by heating. In addition to imidization, this heat treatment also promotes removal of acid anhydrides reacted at the hydroxyl group giving rise to the formation of selectively N-substituted derivatives. These novel chitin derivatives exhibit a much improved solubility in organic solvents and aqueous alkaline solutions. As anticipated, the imide-chitins, derived from trimellitic anhydride and pyromellitic dianhydride, showed reactivity toward amine under heterogeneous conditions, and the reaction capacities toward p-chloroaniline were determined to be 4,2 · 10−4 and 4,6 · 10−4 mol · g−1, respectively.

Water-borne hard coating compositions and processes therefor

Abstract: Water reducible, dispersible coating composition comprising: organic vehicle containing wax compounds of low oil content, neopentyl ester, carboxylic acid, amine, alcoholic coupling solvent, water. Vehicle is preferably amine salt of organic wax of low oil content, long-chain carboxylic acid and neopentyl ester, e.g. C30 acid and pentaerythritol.

The interaction of Cu(II) ion with humic acid

Abstract: The interaction of Cu(II) ion with a humic acid gel was carefully examined as a function of ionic strength and degree of dissociation to test the utility and validity of the fundamental approach developed by the authors for the unambiguous analysis of the protolytic and metal-ion complexation properties of such organic acid substances. Several of the equations developed earlier have been useful for this purpose. Two complexed species, CuS2, where S is believed to be an oxygen atom accessible from ether, aldehyde, ketone, or phenolic groups contained in the three-dimensional array of aromatic rings and their side chains which determine the structure of humic acid, and (RCOOCu+)ν are believed to be the only Cu(II)-bound entities formed. The stability constant of the more strongly complexed CuS2 is approximately 1 × 104; the formation constant of (RCOOCU+)ν is ∼18, a value not too different from the formation constant that has been reported for this particular species when formed by the interaction of Cu(II) with mononuclear carboxylic acid molecules. The sizable variation in pK(HA)νapp of three orders of magnitude, attributed initially to the heterogeneity of humic acid samples, was found to be more likely a consequence of differences in the accessibility of the functional units (RCOOH)ν, (RCOO−)ν, and (RCOOCu+)ν in these condensed systems.