4 documents found, page 1 of 1
Alternative and simple normal-phase HPLC enantioseparation of a chiral amino ac...
Vieira,Joao P. F.; Poletti,Erick F.; Vieira,Renata F. F.; Veredas,Vinicius; Santana,Cesar C.; Nakaie,Clovis R.In this work an alternative chromatographic process was developed for fractionating the (+)-(3R,4R) and ( - )-(3S,4S) enantiomers of the chiral trans β-amino acid trans-2,2,5,5-tetramethylpyrrolidine-3-amino-4-carboxylic acid (POAC), which was protected at its amine group for further coupling to a peptide, polymer or other macromolecule. The HPLC enantioseparation was achieved using a chiral cellulose-based nor...
Effect of polysaccharide capsule of the microalgae Staurastrum iversenii var. a...
Freire-Nordi,Cristina S.; Vieira,Armando A. H.; Nakaie,Clovis R.; Nascimento,Otaciro R.The existence of a mucilaginous envelope, sheath or capsule is usual in many desmids, but few data concerning its function are available. Previous studies of the transport function and permeation of molecules through the algae capsules were done using the algae Spondylosium panduriforme and Nephrocytium lunatum, the Electron Paramagnetic Resonance (EPR) technique, and different spin labels. The results suggeste...
Use of the same polymer for synthesis and purification of peptides
Silva,Elias H.; Etchegaray,Augusto; Carvalho,Regina S. H.; Jubilut,Guita N.; Miranda,Antonio; Nakaie,Clovis R.This work reveals an uncommon but valuable biotechnological approach regarding the use of a same polymer (benzhydrylamine-resin, BHAR) for synthesis and anion exchange purification of peptides. Initially, the octapeptide DRVYIHPF-NH2 was synthesized in 1% and 3% cross-linked BHAR, attaching 2.5 mmol g-1 ammonium groups. Due certainly to its less rigid polymeric backbone, higher synthesis yield (about 80%) was a...
Importance of the solvation degree of peptide-resin beads for amine groups dete...
Cilli,Eduardo M.; Jubilut,Guita N.; Ribeiro,Suely C. F.; Oliveira,Eliandre; Nakaie,Clovis R.The classic and important picric acid method used in polymers biochemical and chemical fields of polymers for amine group quantification was chosen in this work as a model for evaluating the influence of the resin bead solvation during an analytical procedure. It was observed that this method, proposed almost three decades ago, failed to quantify amine groups of peptidyl-resin containing aggregating and polar s...