METHOD FOR THE CONVERSION OF METHYLMERCAPTOPROPIONALDEHYDE FORMED FROM CRUDE ACROLEIN AND CRUDE METHYL MERCAPTAN
申请人:Steffan Martin
公开号:US20130245318A1
公开(公告)日:2013-09-19
A reactive rectification column suitable for the production of 2-hydroxy-4-methylmercaptobutyric acid and/or methionine contains a weir having a height of 100 mm or more.
Preparation and use of methionylmethionine as feed additive for fish and crustaceans
申请人:Kobler Christoph
公开号:US09095161B2
公开(公告)日:2015-08-04
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.
<i>N</i>-Carbamyl-<scp>L</scp>-Amino Acid Amidohydrolase of<i>Pseudomonas</i>sp. Strain NS671: Purification and Some Properties of the Enzyme Expressed in<i>Escherichia coli</i>
An N-carbamyl-L-amino acid amidohydrolase was purified from cells of Escherichia coli in which the gene for N-carbamyl-L-amino acid amidohydrolase of Pseudomonas sp. strain NS671 was expressed. The purified enzyme was homogeneous by the criterion of SDS–polyacrvlamide gel electrophoresis. The results of gel filtration chromatography and SDS–polyacrylamide gel electrophoresis suggested that the enzyme was a dimeric protein with 45-kDa identical subunits. The enzyme required Mn2+ ion (above 1 mM) for the activity. The optimal pH and temperature were 7.5 and around 40°C, respectively, with N-carbamyl-L-methionine as the substrate. The enzyme activity was inhibited by ATP and was iost completely with p-chloromercuribenzoate (1 mM). The enzyme was strictly L-specific and showed a broad substrate specificity for N-carbamyl-L-α-amino acids.
Recent developments in peptide synthesis have underlined the importance of optimising, on a preparative scale, the N-carbamoylation of amino acids by aqueous cyanate. To this purpose, a theoretical model of aqueous cyanate reactivity was designed. The parameters of the model were evaluated, for various pH and temperatures, from a critical survey of the literature, together with additional experimental
Synthesis of Chiral Pyrimidin-2(1H)-ones from N-Carbamoyl Amino Acids
作者:Ilya N. Egorov、Vladimir L. Rusinov、Oleg N. Chupakhin
DOI:10.5560/znb.2013-3129
日期:2013.11.1
A series of previously unknown pyrimidin-2(1H)-ones containing chiral amino acid fragments was synthesized from 1,1,3,3-tetramethoxypropane and N-carbamoyl derivatives of amino acids under acidic conditions.