Abstract: Disclosed is a method for separating lycine and L-serine from a solution containing both of them in the dissolved state and, in particular, a reaction solution obtained from a fermentation or enzymic conversion process for the preparation of L-serine by using glycine as the raw material. This method is based on a chromatographic technique utilizing the differential affinity of L-serine and glycine for a strongly acidic ion exchange resin.

Abstract: Hydrochloric acid is added to a solution containing L-cysteine, L-cystine, L-serine and an inorganic salt until it contains at least 15% by weight of hydrochloric acid. The solution is held at a temperature of at least 20.degree. C. so that the L-cystine and the inorganic salt may form a solid, and the solid is removed from the solution. The solution is cooled to a temperature not exceeding 10.degree. C., so that crystallization may take place to form the monohydrate of L-cysteine hydrochloride. The monohydrate is separated from the L-serine in the solution.

Abstract: The invention relates to a process for the separation of L-leucine and L-isoleucine. The process is carried out by subjecting a mixture of leucine ester, and isoleucine ester, (or a mixture of leucine ester, isoleucine ester and valine ester) to an esterase catalyzed hydrolysis resulting in a selective hydrolysis of the leucine ester. The pure L-leucine can be isolated from the reaction mixture by first removing the non-hydrolyzed esters by extraction with an organic solvent and then crystallizing the L-leucine at its isoelectric point. The recovered L-iso-leucine ester is purified by distillation (if necessary), and hydrolyzed to yield pure crystalline L-isoleucine.

Abstract: A process for separating basic amino acids from a liquid containing the same using cation exchange resin towers in series, which comprises effecting repetitive adsorption and elution steps in sequence, wherein the washing water employed in said adsorption and elution steps is obtained by recycling the latter portion of a liquid discharged from a first tower of the adsorption step into an adsorption step in a subsequent cycle, or by recycling a liquid discharged from a first tower at the elution step into an elution step in a subsequent cycle.

Abstract: A method for separating a basic amino acid from a liquor containing the same, which entails (a) contacting the basic amino containing liquor with a strongly acidic cation exchange resin at a pH at which the basic amino acid exists in the form of a divalent cation, thereby adsorbing at least a part of the basic amino acid in the form of the divalent cation; (b) contacting said ion exchange resin with a liquor containing said basic amino acid and a neutral amino acid or an acidic amino acid at a pH at which the basic amino acid exists in the form of a monovalent cation; (c) passing an eluant through said ion exchange resin, thereby eluting the basic amino acid from the ion exchange resin; and (d) separating and recovering the basic amino acid from the eluate.

Abstract: (Benzothiadiazine, benzamido and benzenesulfonyl)phenyl-substituted carboxyalkyl dipeptide compounds are disclosed. Compounds of this invention are useful as antihypertensive agents.

Abstract: The present invention relates to a spherical amino acid having an average particle size of about 1 mm or below and a process for the preparation thereof.

Abstract: A process for the total or partial elimination of aspartic acid and glutamic acid from a protein hydrolyzate or a mixture of aminoacids is described, which consists of passing the hydrolyzate or mixture of aminoacids in solution on an anion exchange resin and then washing with water or eluting the aminoacids from the resin. Aspartic acid and glutamic acid are at least partially separated from the other aminoacids because of their affinity for the resin which is greater than the affinity of the other aminoacids. The resulting mixtures of aminoacids may be used as such or may be further adjusted by addition of valine, leucine, isoleucine, and arginine to give products valuable in clinical nutrition.

Abstract: Amino acids can be purified and/or concentrated by extracting aqueous mixtures such as fermentation broths by contacting an aqueous mixture containing amino acids with an organic solution containing a water insoluble extractant.

Abstract: There is disclosed a process for reducing the reaction time in the hydrolysis of a condensation polymer wherein molten condensation polymer is intimately admixed with a depolymerizing agent which is either (i) one of the products resulting from the complete hydrolytic depolymerization of the condensation polymer; or (ii) water. The depolymerization agent is present in the mixture in an amount which is less than the weight of the condensation polymer and the materials are intimately admixed for a time sufficient that the molecular of the condensation polymer is reduced by at least 50%. The treated condensation polymer of lower molecular weight is thereafter subjected to neutral hydrolysis. In addition to decreasing the overall time required to effect complete hydrolytic depolymerization, this process additionally permits the use of a smaller hydrolysis vessel, thereby reducing the fabrication cost of the hydrolysis unit.

Abstract: Novel octopine derivatives are disclosed which are useful for the selective growth of the agriculturally useful A. tumefaciens bacterium along with a synthetic method for their preparation. Also disclosed is a method of separating octopine derivatives from their diastereoisomers along with a method of selectively growing strains of the bacterium A. tumefaciens.

Abstract: This is a method for separating or purifying an amino acid from a mixture including other substance such as an inorganic salt other than the amino acid and/or a mutual mixture of amino acids including the amino acid by means of piezo-dialysis employing an amphoteric ion exchange membrane. This membrane is made from a ternary block copolymer having a molecular structure of straight chain in which first macro-molecule with a cation exchange group, second macromolecule with an anion exchange group and third macromolecule without ion exchange group are linked together.

Abstract: A process for producing nitrilotriacetate salts from nitrilotriacetonitrile in which a mixture of substantially stoichiometric amounts of an alkali metal hydroxide and nitrilotriacetonitrile in water are partially hydrolyzed, followed by boiling to complete the reaction, followed by addition of a bleaching agent, and recovery of the product as a solution or in crystalline form.

Abstract: A method for the extraction of certain amino acids from aqueous solutions by contacting said solutions with various dithiophosphinates in conjunction with a polar diluent is disclosed.

Abstract: Amino acid fractions of different composition are obtained at different times by fractional filtration after neutralization of the hydrolysates. Tyrosine-rich and leucine-rich fractions are specifically treated and lead to the recovery of L-tyrosine, L-cystine, L-leucine and L-phenyl-alanine.

Abstract: A method for separating an ionic substance from a liquid medium, which comprises including a metal ion, a metal oxide ion, a metal complex ion, ammonium compounds, etc. dissolved or dispersed in the liquid medium by using a fluorine containing compound of the following formula[{Rf-(A).sub.a -Y}(X).sub.b ].sub.n (Z).sub.ccontaining a fluoroalkyl group (Rf) having 3 to 20 carbon atoms and a group (Y) having affinity for the ionic substances. A composition for trapping ionic substances, comprising the aforesaid fluorine-containing compound as a main ingredient. The invention can be advantageously applied to the recovery of useful metals from ocean waters.

Abstract: Provided is a method of increasing the purity of amphoteric compound compositions. The method is: (a) providing an amount of a crude amphoteric compound composition, (b) using a portion of the crude composition to prepare in solution a cationic salt of the amphoteric compound, (c) using another portion of the crude composition to prepare in solution an anionic salt of the amphoteric compound, (d) mixing together the solutions wherein a precipitate is formed, and (e) collecting the precipitate which is an amphoteric compound composition of higher purity than the crude composition.

Abstract: A process for recovering omega-amino-dodecanoic acid by separating the byoducts from the crude acid that comprises, in the sequence indicated (a) treating the crude acid in the presence of water with an acid (A) in such an amount as to obtain an acid (A)/amino acid molar ratio comprised of between 2:1 and 1:1, the amount of water being such as to dissolve at least part of the salt obtained and not to dissolve at least part of the by-products, (b) separating the phases into one containing most of the salt and another containing most of the by-products, (c) decomposing the salt by treatment with an organic or inorganic base (B) and isolating the amino acid in the free state.

Abstract: Aqueous sodium methioninate solutions having a low content of sodium carbonate can be recovered from the crude hydrolysis mixture resulting from the saponification of 5-(.beta.-methylmercaptoethyl)hydantoin with 1.1 to 6 equivalents of sodium hydroxide and/or sodium carbonate by cooling the crude hydrolysis mixture to a temperature below 10.degree. C., separating off the precipitated sodium carbonate and concentrating the sodium methioninate solution remaining to 40 to 65 weight percent.

Abstract: Aqueous sodium methioninate solutions having a low content of sodium carbonate can be recovered from the crude hydrolysis mixture resulting from the saponification of 5-(.beta.-methylmercaptoethyl)-hydantoin with 1.1 to 6 equivalents of sodium hydroxide and/or sodium carbonate by distilling off the water from the crude hydrolysis mixture until the sodium methioninate content is 40 to 65 weight percent, and after cooling to at most room temperature separating off the precipitated sodium carbonate.

Abstract: Amino acid fractions of different composition are obtained at different times by fractional filtration after neutralization of the hydrolysates. Tyrosine-rich and leucine-rich fractions are specifically treated and lead to the recovery of L-tyrosine, L-cystine, L-leucine and L-phenyl-alanine.

Abstract: A process for recovering carboxylic acids with a material of which the main component is a polymeric compound having a pyridine skeletal structure and a crosslinked structure, followed by desorbing the captured carboxylic acids by use of a desorbing agent.

Abstract: From a mixture of isoleucine and leucine in a ratio by weight of at least 3:7, the isoleucine is precipitated in an anhydrous solvent, particularly methyl ethyl ketone, using concentrated sulphuric acid. The precipitate is separated and freed from sulphuric acid, for example by neutralisation with barium hydroxide after elimination of the solvent. Industrial production of marketable isoleucine from a mixture still containing leucine.

Abstract: A novel separation process of an iminodiacetic acid component from an aqueous glycine solution including the same is provided. In this process, sulfuric acid is added, in the presence of sodium salt, to the aqueous glycine solution in such an amount that the pH of the aqueous glycine solution becomes 1.5 or less, whereby the iminodiacetic acid is crystallized from the solution and, then, the crystallized iminodiacetic acid component is separated from the mother liquor. Thus, glycine can be efficiently recovered without causing undesirable accumulation of the iminodiacetic acid component in the mother liquor.

Abstract: The invention relates to a process for the recovery of .alpha.-hydroxy- and .alpha.-amino-carboxylic acids from sugary media containing them.According to the process of the invention:in a first phase, the mixture from which it is proposed to recover the .alpha.-hydroxy- or .alpha.-amino-carboxylic acid and which contains the latter in the form of its calcium salt is contacted with a cationic resin in the calcium form for a sufficient time to reach optimal adsorption of said calcium salt and then,in a second phase, the previously saturated resin is eluted by resorting to water.The process according to the invention enables the quantitative production of a pure calcium salt.

Abstract: A solution of leucine, isoleucine and valine is concentrated at a pH-value of from 1.5 to 2.0 to produce a mother liquor enriched with isoleucine and valine and a solid phase enriched with leucine. Concentrated hydrochloric acid is added to the mother liquor enriched with isoleucine and valine and, after concentration, a mother liquor enriched with valine and leucine and a solid phase enriched with isoleucine are obtained.

Abstract: Pure L-cystine is recovered from a mixture with other aminoacids by fractional crystallization in presence of acids and water from an alcoholic medium.

Abstract: Methionine devoid of a coloring matter can be obtained from the aqueous solution of alkali salts of methionine prepared by hydrolysis of 5-(.beta.-methylmercaptoethyl)-hydantoin with an alkali by decolorizing the said solution with reducing sulfur compound and thereafter collecting methionine as colorless crystals.

Abstract: The isomers of synthetic insect sex pheromones or their precursors are separated by selectively forming an inclusion complex with the E-isomer and urea or thiourea. In order for the E-isomer complex to form selectively it is necessry that the mono-olefin which forms the complex have a primary, linear chain of at least 7 atoms, a molecular diameter of 2.8-6A, and a polar functional group having transverse dimensions of less than 6A. Branching between the olefinic bond and the polar functional group is limited to methyl groups.

Abstract: The separation of constituents is carried out in such a way that a mixed amino acid sample is supplied to a separation column packed with a cation exchange resin and that, during the analysis of the single sample, five sorts of elutes of different compositions are supplied to the separation column in succession and by stages. The pH of the elute at the second stage is held higher than that of the elute at the first stage, and the pH's of the elutes at the third to fifth stages are held successively higher. However, the pH of the elute at the third stage is held lower than that of the elute at the second stage. On the other hand, the concentrations of counter ions contained in the elutes at the first to fifth stages are held successively higher inversely to the order in which the elutes are supplied. Notwithstanding that the pH of the elute at the third stage is lowered, the broadening of a component peak can be prevented by the increase of the counter ion concentration.