Synthesis of Polypeptides with Known Repeating Sequence of Amino Acids

Synthesis of polyamides from rigid and sterically hindered dicarboxylic acids and diamines under mild conditions

“…Until now, the polycondensation of amino acids and their sequences have been prepared almost exclusively by using 4-nitrophenyl ester derivatives. [12][13][14][15][16][17][18] The success of such polycondensations was due primarily to the fact that primary amine groups and sterically less hindered acids were used in powerful solvents, like DMF and DMSO. From the results obtained, we may conclude that N-hydroxysuccinimide and 2,4-dinitrophenyl diesters should be at least equivalent to and, in less polar solvents, even superior to the 4-nitrophenyl esters method.…”

Peptides Synthesis: Coupling of Pentachlorophenyl-active Ester Hydrochlorides of Di-and Tripeptides with N-Carbobenzoxy Amino Acids through Mixed Anhydride Method

“…Pentachlorophenyl esters, which are among the most active esters (l), afford an excellent method for the synthesis of peptides and polypeptides with an ordered sequence of amino acids (2)(3)(4)(5). We recently reported that pentachlorophenyl active esters of N-carbobenzoxy amino acids couple in satisfactory yields with amino acids and peptides C-protected by dicyclohexylamine, which can be conveniently removed by mild acid treatment at the end of the synthesis (6,7).…”

Peptides synthesis: Coupling of pentachlorophenyl active esters of N-carbobenzoxy amino acids and peptides to the pentachlorophenyl active ester hydrochlorides of amino acids

“…Recently we reported a routine assay for conjugated and unconjugated chlorpromazine metabolites in human urine (1). The group of conjugated chlorpromazine metabolites was assayed by passing a small volume of urine through an ionexchange resin to remove unconjugated drug metabolites and some contaminating endogenous urinary constituents.…”

“…Pentachlorophenyl active esters afford a satisfactory method for the synthesis of peptides and polypeptides with the ordered sequence of amino acids (1)(2)(3). One of the main advantages in the use of pentachlorophenyl esters is their relatively higher melting points which lead to easy crystallization and purification.…”