摘要:
The invention relates to a process for the production of 2-hydroxy-4-methylthiobutyric acid ammonium salt from 2-hydroxy-4-methylthiobutyronitrile, and to the use of the 2-hydroxy-4-methylthiobutyric acid ammonium salt produced by this process.
摘要:
The invention relates to recombinant microorganisms which, in comparison to the starting organism, have a higher concentration or activity of a D-amino acid oxidase, of an L-amino acid dehydrogenase, of an NADH cosubstrate regenerating enzyme and, if necessary, of a catalase. The invention also includes methods for preparing L-amino acids from D-amino acids using of these microorganisms.
摘要:
A method for preparing 3-(methylthio)propanal and 2-hydroxy-4-(methylthio)butanenitrile by catalyzed addition of methylmercaptan to acrolein and hydrogen cyanide to 3-(methylthio)propanal.
摘要:
A process for the preparation of &agr;-amino acids by hydrolysis of hydantoins in the presence of water and at least one metallic oxide under conditions such that all the starting materials are completely dissolved in the water as a result of high pressure and high temperature and only one further phase is present in the reactor in addition to the metallic oxide phase.
摘要:
A process for the production of 2-hydroxy-4-methylmercaptobutyric acid (MHA) by electrochemical carboxylation of 3-methylmercapto-propionaldehyde in an undivided electrolytic cell containing a sacrificial anode, in an aprotic solvent in the presence of a supporting electrolyte. Preferred anode/cathode combinations are Mg/Mg and Mg/carbon. MHA is obtainable in a high yield.
摘要:
The present invention relates to a catalyst which comprises a support material and an oxidic composition containing at least one alkali metal and tungsten, a process for producing such catalysts and also a process for preparing alkyl mercaptans by reaction of alkanols with hydrogen sulphide in the presence of such a catalyst.
摘要:
This disclosure relates to a process for preparing D,L-methionine by feeding carbon dioxide to an aqueous potassium methioninate solution obtained by hydrolysis of 5-(2-methylmercaptoethyl)hydantoin, in order to precipitate out crude methionine, which is separated off and purified. In this process an aqueous solution of the separated-off crude methionine is purified by recrystallization from a solution containing potassium ions and also a crystallization additive. The crystallization additive is a nonionic or anionic surfactant, or a mixture of different nonionic or anionic surfactants. The recrystallization occurs by introducing a 60 to 110° C.-hot methionine solution into a 35 to 80° C.-warm methionine suspension, a temperature of which is lower than that of the introduced solution, such that the temperature of the methionine suspension being maintained between 35 and 80° C. during the addition. The crystallization additive is a sorbitan fatty acid ester or a mixture of different sorbitan fatty acid esters.
摘要:
An animal feed mixture containing DL-methionyl-DL-methionine and salts thereof for animals kept in aquacultures is provided. Methods for preparing DL-methionyl-DL-methionine of formula (I) and methods to fractionate the diasteriomeric forms obtained are also provided.
摘要:
The present invention relates to a catalyst which comprises a support material and an oxidic composition containing at least one alkali metal and tungsten, a process for producing such catalysts and also a process for preparing alkyl mercaptans by reaction of alkanols with hydrogen sulphide in the presence of such a catalyst.
摘要:
A method is described to prepare a Mo containing supported catalyst comprising TeO2 as active promoter and a process for preparing methanethiol in the presence of said catalyst.