Telechelic associative polymers such as Hydrophobically modified ethoxylated urethanes (HEURs) are an important class of rheology additives used in many industrial fields allowing a precise control the rheology. To avoid use toxic isocyanates, more eco-friendly HEURs were synthesized based on cyclo-carbonate/amine addition reaction. hydroxyurethanes (HEHURs) thus obtained by aminolysis telechel...

Amide syntheses remain a key challenging green chemistry reaction. For instance, synthesis of N-acyl glycines as biosurfactants and therapeutics is highly desirable to replace chemical pathways using toxic phosgene. Herein, we report novel concept for enzymatic amidation in an aqueous system via glycerol activation fatty acids theirsubsequent aminolysis with glycine synthesize glycines. We then...

Lipases are one of the most important industrial biocatalyst which catalyzes the hydrolysis of lipids. It can also reverse the reaction at minimum water activity. Because of this pliable nature, it is widely exploited to catalyze the diverse bioconversion reactions, such as hydrolysis, esterification, interesterification, alcoholysis, acidolysis and aminolysis. The property to synthesize the es...

Because the specificity profile of the membrane anchor-free G57-V577 penicillin-binding protein 3 (PBP3) of Escherichia coli for a large series of beta-lactam antibiotics is similar to that of the full-size membrane-bound PBP, the truncated PBP is expected to adopt the native folded conformation. The truncated PBP3 functions as a thiolesterase. In aqueous media and in the presence of millimolar...

Kinetic studies on the pyridinolysis of aryl dithiocyclopentanecarboxyaltes 2 were carried out at 60.0 C in acetonitrile. In the aminolysis of 2, the βX values were 0.5 0.8 with anilines, and there was no breakpoint. However, in the pyridinolysis of 2, biphasic Brönsted plots were obtained, with a change in slope from a large value (βX ≅ 0.7) to a small value (βX ≅ 0.4) at pKa = 5.2. This was a...

Phenylacetylene-based [2]rotaxanes were synthesized by a covalent-template approach by aminolysis of the corresponding prerotaxanes. The wheel and the bulky stoppers are made of phenylene-ethynylene-butadiynylene macrocycles of the same size. The stoppers are large enough to enable the synthesis and purification of the rotaxane. However, the wheel unthreads from the axle at elevated temperature...

The S' subsite specificity of bovine trypsin has been studied by partitioning of o-nitrophenylsu1fenyl-Larginyl-trypsin (formed using o-nitrophenylsulfenyl-L-arginine alkyl esters as acyl donors) between various amino acid-derived nucleophiles and water. The data obtained from spectrophotometric measurements confirmed a preference of trypsin for arginine residues in the Pi-position, which is le...

The strategy of combined site directed mutagenesis and chemical modification creates chemically modified mutants (CMMs) with greatly broadened substrate specificities. We have previously reported that the CMMs of subtilisin Bacillus lentus (SBL) are efficient catalysts for the coupling of both Land D-amino acids. We now report that these powerful catalysts also allow amide bond formation betwee...

Surface modification of polymeric scaffolds for biomedical applications is a versatile and widely used method to improve interactions between cells. Specifically, chemical immobilization proteins provides significant advantages such as stable biocompatible properties, however, it generally requires expensive instruments or complex steps. In this study, the facile presented that changes poly (l-...