Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/7759
Título: | ΔG(CH2) as solvent descriptor in polymer/polymer aqueous two-phase systems |
Autor(es): | Madeira, Pedro Teixeira, J. A. Macedo, Eugénia Mikheeva, Larissa M. Zaslavsky, Boris Y. |
Palavras-chave: | Aqueous two-phase partitioning Hydrophobicity Amino acids Tryptophan Peptides Monosaccharides |
Data: | Mar-2008 |
Editora: | Elsevier B.V. |
Revista: | Journal of Chromatography A |
Citação: | "Journal of Chromatography A". ISSN 0021-9673. 1185:1 (21 Mar. 2008) 85-92. |
Resumo(s): | Phase diagrams were determined for aqueous two-phase systems (ATPSs) formed by different paired combinations of Dextran (Dex-75), Ficoll-70, polyethylene glycol (PEG-8000), hydroxypropyl starch (PES-100), and Ucon50HB5100 (a random copolymer of ethylene glycol and propylene glycol) all containing 0.15 M NaCl in 0.01 M phosphate buffer, pH 7.4, at 23 °C. Partition coefficients of a series of dinitrophenylated (DNP) amino acids with aliphatic side-chains were studied in all the ATPSs at particular polymer concentrations. Free energies of transfer of a methylene group between the coexisting phases, ΔG(CH2), were determined as measures of the difference between the hydrophobic character of the phases. Furthermore, partition coefficients of tryptophan (Trp) and its di- and tri-peptides and a set of p-nitrophenyl (NP)-monosaccharides were measured in all the two-phase systems, and the data obtained compared with the ΔG(CH2) values obtained in the systems. It was established that for eight out of 10 of two-phase systems of different polymer compositions the partition coefficients for Trp peptides correlate well with the ΔG(CH2) values. Similar correlations for NP-monosaccharides were valid for seven out of 10 two-phase systems. These observations indicate that the difference between the hydrophobic characters of the coexisting phases represented by the ΔG(CH2) value cannot be used as a single universal measure for comparison of the ATPSs of different polymer compositions. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/7759 |
DOI: | 10.1016/j.chroma.2008.01.035 |
ISSN: | 0021-9673 |
Versão da editora: | http://www.sciencedirect.com/science/journal/00219673 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
---|---|---|---|---|
Madeira_J_ChromA[2].pdf | 238,64 kB | Adobe PDF | Ver/Abrir |