Abstract: Food supplement containing alpha-keto acids for supporting diabetes therapy. The present invention relates to a formulation which is used as food supplement and contains alpha-keto acids for supporting therapy in diabetes mellitus type II (DM).

Abstract: Food supplement containing alpha-keto acids for supporting diabetes therapy. The present invention relates to a formulation which is used as food supplement and contains alpha-keto acids for supporting therapy in diabetes mellitus type II (DM).

Abstract: The present invention relates to a process for the resolution of DL-racemic mixtures of compounds which crystalize in the form of a conglumerate. Both, the D and L-enantiomers are obtained according to the invention in a industrially feasable process by adding chiral enantioselective polymers to the supersaturated solution of the racemat to inhibit crystalization of one enantiomer. Next a DL-racemic mixture of said compound is suspended in about twice the amount of the crystallized enantiomer. Consequently, the opposite enantiomer could be recovered by said suspension by physical separation.

Abstract: A method of isolating 1-[N2-((S)-ethoxycarbonyl)-3-phenylpropyl)-N6-trifluoroacetyl]-L-lysyl-L-proline (lisinopril (TFA) ethyl ester, LPE). The solvent or solvent mixture used for the extraction is also a main constituent of the solvent or solvent mixture from which the crystallization takes place. High yield as well as good purity of the end product are obtained, without distillation. 1-[N2-((S)-ethoxycarbonyl)-3-phenylpropyl)-N6-trifluoroacetyl]-L-lysyl-L-proline (lisinopril (TFA) ethyl ester, LPE) is described as a precursor for producing an ACE inhibitor.

Abstract: The invention concerns a process for the enzymatic preparation of protected di- and oligopeptides and the separation of the protective groups used. The process according to the invention enables peptides to be synthesized simply and economically and the protective group to be separated carefully. The process comprises three reaction steps: 1. Preparation of N-carbamoyl amino acid or N-carbamoyl amino acid derivatives; 2. Formation of the peptide bond between the carbamoyl-protected electrophile and nucelophile; and 3. Separation of the carbamoyl-protective group.

Abstract: The invention pertains to a process for the continuous production of basic cyclic optically active .alpha.-amino acids of general formula (I) by continuous racemate splitting via diastereomeric salt pairs with re-racemisation of the residual amino acid or amino acid derivative in the mother liquid with the aid of an optically active acid.

Abstract: A process employs amidine or amidine base and a metal compound in the presence of an alcohol or water to transesterify, or saponify esters or amides. Since the process employs relatively mild conditions, it is especially suitable for the production of optically active substances and biomolecules, e.g. peptides, amino acids and nucleic acids which are sensitive to elevated temperatures, extreme pH values and/or long reaction times since these compounds are easily racemised or denatured. The conditions additionally find use in solid phase systems. When amino acid or peptide esters are saponified, the splitting is brought about with lithium hydroxide alone under mild conditions. The use of an amidine base, more particularly DBU or DBN, in combination with the metal salt additionally accelerates the reaction so strongly that even sensitive acid derivatives can be reacted under mild conditions.

Abstract: The invention relates to a new process for the preparation of optically active amino acids and amino acid derivatives of the general formula (I), wherein *, X and R.sup.1 to R.sup.4 have the meaning given in the description. Starting from commercially obtainable (-)-menthol or (+)-menthol, the enantiomerically pure compounds of the formula (I) are obtained in high yields. The method is particularly suitable for the preparation of sterically demanding amino acids and amino acid derivatives.

Abstract: A process for producing 2-[3(S)-amino-2-(R)-hydroxyl-4-phenyl butyl]-N-tert,butyl decahydro-(4aS,8aS)-isoquinoline-e(S)-carboxamide of the formula (I) via 3(S)-[lower alkoxy carbonyl amino, phenoxy carbonyl amino or benzyl oxycarbonyl amino]-2-hydroxy-4-phenyl butyric acid and process for producing said acid.

Abstract: Disclosed is a process for producing .beta.-amino-.alpha.-hydroxycarboxylic acid derivatives of general formula (2R,3S)- or (2S,3E)-N-(X,Y)-3-amino-2-hydroxy-3-phenyl propionic acid-Z of Formula I, ##STR1## e.g. of (2E,3S)-3-amino-2-hydroxy-3-phenyl propionic acid or (2R,3S)-N-benzoyl-3-amino-2-hydroxy-3-phenyl propionic acid methylester. Compounds of type I are valuable intermediates in the total synthesis of Taxols which can be used in the treatment of various forms of cancer.

Abstract: A method of isolating 1-?N.sup.2 -((S)-ethoxycarbonyl)-3-phenylpropyl)-N.sup.6 -trifluoroacetyl!-L-lysyl-L-proline (lisinopril (TFA) ethyl ester, LPE). The solvent or solvent mixture used for the extraction is also a main constituent of the solvent or solvent mixture from which the crystallization takes place. High yield as well as good purity of the end product are obtained, without distillation. 1-?N.sup.2 -((S)-ethoxycarbonyl)-3-phenylpropyl)-N.sup.6 -trifluoroacetyl!-L-lysyl-L-proline (lisinopril (TFA) ethyl ester, LPE) is described as a precursor for producing an ACE inhibitor.

Abstract: A process for producing 2-?3(S)-amino-2-(R)-hydroxyl-4-phenyl butyl!-N-tert,butyl decahydro-(4aS,8aS)-isoquinoline-e(S)-carboxamide of the formula (I) via 3(S)-?lower alkoxy carbonyl amino, phenoxy carbonyl amino or benzyl oxycarbonyl amino!-2-hydroxy-4-phenyl butyric acid and process for producing said acid.

Abstract: A process is disclosed for reducing amino acids and derivatives thereof Compounds of formula (I), in which n=0 or 1 and R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 have the meanings given in the description, are reduced to the corresponding amino alcohols of formula (II): the formula (I) compounds are converted in a first step, in at least one alcohol and with the addition of acid and heat to an ester, this process producing a reaction mixture containing the ester; the ester is converted in a second reaction step with alkali or alkaline earth borohydride to compounds of formula II. By specifying that the second step be carried out without isolating the ester from the reaction mixture and by using alkali or alkaline earth borohydrides which are not activated, the invention facilitates the production from amino acids and their derivatives of the correponding alcohols in a simple "single vessel" process, with high yields and in such a way as to preserve a given centre of chirality.

Abstract: A method is disclosed by which N-carbamoyl-(R)-tert.-leucine is obtained from tert-butyl hydantoin by means of an (R)-specific hydantoinase, in which N-carbamoyl-(R)-tert.-leucine is converted by reaction with nitrite or an (R)-carbamoylase to (R)-tert-leucine.

Abstract: Method for the preparation of N-protected 4-ketoproline derivatives of formula I ##STR1## by oxidation of the corresponding N-protected 4-hydroxyproline derivatives of ##STR2## using the system TEMPO (2,2,6,6-tetramethylpiperidinyl oxy free radical)/NaOCl.

Abstract: A process for purifying 1-[N.sup.2 -((S)-ethoxycarbonyl)-3-phenylpropyl)-N.sup.6 -trifluoroacetyl]-1-lysyl-1-proline by extraction and crystallization. The process includes a two step extraction in a two phase aqueous/organic solvent system and crystallization from organic solvent.

Abstract: The invention relates to a method of preparing 5-(aminoalkyl)-hydantoins with basic side chain in which the protection of the amino function in the side chain is necessary during the formation of the hydantoin requires minimal expense.

Abstract: A method of producing optically active pyrrolidines of the general formula ##STR1## in which R.sup.1 is hydrogen or OH,R.sup.2 is a benzyl group which can have one or more alkyl-, alkoxy- and/or halogen substituents on the aromatic, and* is and/or can be an asymmetric center,by reducing the corresponding, enantiomerically pure pyrrolidinediones using activated alkali boron hydride.

Abstract: N-substituted .alpha.-amino acids and dipeptides are valuable intermediate products for the production of inhibitors of the angiotensin converting enzyme (ACE); representatives are e.g. enalapril and ramipril. These compounds are prepared by means of hydrogenolytic conversion of a primary amine with a ketone with the addition of an organic or inorganic base; among the inorganic bases, basic aluminum oxide is preferred. The use of chiral organic bases favors the production of a diastereomer.

Abstract: 2.2. 1,3-imidazolidine-4-ones having the General Formula: ##STR1## are obtained in a pure form especially by means of precipitation, in which production an optically active acid can be used at 0.5-0.8 eq. for the separation of racemates. The non-desired enantiomer can be racemized in an inert solvent and the cyclization to imidazolidinone can take place by means of the optically active acid, whereupon the separation of racemates takes place directly thereafter. 1,3-imidazolidine-4-ones are valuable educts for the preparation of branched or unbranched, proteinogenic or non-proteinogenic .alpha.-amino acids by means of diastereoselective alkylation and subsequent ring splitting.