2766-18-9Relevant articles and documents
Organocatalyzed Asymmetric Aldol Reaction of α-Keto Amides with A Tripeptide Catalyst
Kon, Kazumasa,Takai, Hiromu,Kobayashi, Takumu,Kohari, Yoshihito,Murata, Miki
, p. 829 - 832 (2021/02/26)
An organocatalyzed asymmetric aldol reaction of α-keto amides was developed. An N-terminal 4- trans -siloxyproline-based tripeptide with an l - tert -leucine unit adjacent to the 4- trans -siloxyproline residue was used to catalyze the reaction between various α-keto amides and acetone, to produce the corresponding aldol adducts with up to 99% yield and 91% ee.
One-step C-terminal deprotection and activation of peptides with peptide amidase from stenotrophomonas maltophilia in neat organic solvent
Arif, Muhammad I.,Toplak, Ana,Szymanski, Wiktor,Feringa, Ben L.,Nuijens, Timo,Quaedflieg, Peter J. L. M.,Wu, Bian,Janssen, Dick B.
, p. 2197 - 2202 (2014/07/21)
Chemoenzymatic peptide synthesis is a rapidly developing technology for cost effective peptide production on a large scale. As an alternative to the traditional C→N strategy, which employs expensive N-protected building blocks in each step, we have investigated an N→C extension route that is based on activation of a peptide C-terminal amide protecting group to the corresponding methyl ester. We found that this conversion is efficiently catalysed by Stenotrophomonas maltophilia peptide amidase in neat organic media. The system excludes the possibility of internal peptide cleavage as the enzyme lacks intrinsic protease activity. The produced peptide methyl ester was used for peptide chain extension in a kinetically controlled reaction by a thermostable protease.
Synthesis and in vitro evaluation of macromolecular antitumour derivatives based on phenylenediamine mustard
De Winne, Katleen,Seymour, Leonard W.,Schacht, Etienne H.
, p. 159 - 168 (2007/10/03)
Poly-[N-(2-hydroxyethyl)-l-glutamine] (PHEG) and poly(ethylene glycol) (PEG)-grafted PHEG conjugates of N,N-di(2-chloroethyl)-4-phenylenediamine mustard (PDM) were synthetised. A collagenase-sensitive oligopeptide spacer was selected to link the cytotoxic agent PDM onto the polymeric carrier. First, the oligopeptide-drug conjugate, l-pro-l-leu-gly-l-pro-gly-PDM, was prepared. In a second step, the low molecular weight PDM derivative and PEG-NH2 were coupled to a N,N-disuccinimidylcarbonate activated PHEG. Dynamic laser light scattering measurements indicated the formation of aggregates. The presence of human serum albumin had no significant effect on the diameter of the conjugates. The hydrolytic stability of the conjugates was investigated in buffer solutions. The conjugates showed an improved stability compared to the parent nitrogen mustard. The enzymatic degradation studies of the polymeric conjugates were performed in the presence of collagenase type IV (Clostridiopeptidase A; EC 3.4.24.3), cathepsin B (EC 3.4.22.1), cathepsin D (EC 3.4.23.5) and tritosomes. Only the bacterial collagenase type IV was able to cleave the spacer releasing free PDM and its peptidyl derivative, gly-l-pro-gly-PDM. The in vitro cytotoxicity of the conjugates was evaluated against HT1080 fibrosarcoma cells and MDA adenocarcinoma cells. All conjugates showed low toxicity towards these cell lines.