Treatment of 16 α-amino acidesters with isoamyl nitrite in the presence of a small amount of organic acid in chloroform or benzene, followed by chromatographic purification on alumina was found to afford the corresponding α-substituted-α-diazo esters (1) in fairly good yields.
Exclusive formation of amino acid esters took place at an appreciable rate in the CuII-catalysed solvolysis of 6,6â²-(α-alanylamino or α-phenylalanylamino)-2,2â²-bipyridine in alcoholâborate buffer (pH 7.2) solutions at 20 °C via formation of an amide-O-coordinated complex, even though appreciable amounts of water (0â40% v/v) were present in the solution.
Process for the production of L-aspartyl-L-phenylalanine ester
申请人:AJINOMOTO CO., INC.
公开号:EP0154472A2
公开(公告)日:1985-09-11
L-Aspartyl-L-phenylalanine R-ester (APR), wherein R-ester is an ester residue of an alcohol of 2 or more carbon atoms or substituted or unsubstituted phenol, is prepared in higher yield than the corresponding methyl ester (APM) by the action of a microorganism or enzymic product thereof on L-aspartic acid and L-phenylalanine R-ester. Certain genera of microorganism are specified, and certain species are exemplified.
Chemo-Enzymatic Synthesis of Optically Active Amino Acids and Peptides
作者:Shui-Tein Chen、Kung-Tsung Wang
DOI:10.1002/jccs.199900046
日期:1999.6
AbstractThe industrial alkaline protease, alcalase, is stable and active in a high concentration of organic solvents and useful as a biocatalyst for (i) diastereoselective hydrolysis of peptide esters and preparation of racemization‐free peptides; (ii) selective incorporation of esters of D‐amino acid into peptides in t‐butanol via a selective hydrolysis of esters of D,L‐amino acid, followed by using the unhydrolyzed D‐esters as a nucleophile in a kinetically controlled peptide bond formation; (iii) resolution of esters of amino acid in 95% t‐butanol/5% water, followed by saponification of the unreacted esters to offer both enantiomers with high yield and optical purity; (iv) completely resolve amino‐acid esters with high yield and optical purity via in situ racemization of the unreacted antipode catalyzed by pyridoxal 5‐phosphate; (v) cryobioorganic synthesis of peptides with increased yields 15%–40% of peptide bond formation by reaction at 5 °C instead of 25–30 °C of a kinetically controlled enzymatic reaction in alcohols.