Abstract:
Insoluble enzyme complexes are prepared by chemically bonding enzymes to natural sponge. The enzyme can be either directly bonded to the sponge, or the sponge can be first modified with an appropriate chemical reagent, such as a cyclic dicarboxylic acid anhydride, prior to chemical bonding with the enzyme.
Abstract:
A process for the preparation of 2-thionoxazolidone-5 and derivatives thereof is disclosed wherein tertiary alkyl esters of secondary amino carboxylic acid or the N-thiocarbonyl chloride of an Alpha -secondary aminocarboxylic acid is subjected to the action of a proton yielding acid. The compounds produced by the process of this invention are useful as amino acid derivatives in the synthesis of peptides.
Abstract:
1331714 Peptides STAMICARBON NV 19 April 1971 [18 Feb 1970] 23565/71 Heading C2C Peptides are prepared by reacting a free amino hydrogen of an amino acid or an initial peptide or a compound derived therefrom (e.g. an ester or amide or an amino acid or peptide bound to a solid polymeric carrier by its C- terminal COOH group) with a 2-thionooxazolidone-5 compound of formula wherein R 1 is H or an α-amino acid residue, R 2 is H or optionally substituted C 1-3 alkyl and R 3 is H or C 1-3 alkyl, or wherein R 1 and R 3 together represent a C 1-3 alkylene group forming an α-amino acid residue in which the amino group forms part of a ring. N-thiocarboxylated derivative is first which may be dethiocarboxylated by lowering the pH below 5. The first step is preferably carried out at a pH between 8 and 12.