Characterization of interactions between polyphenolic compounds and human serum proteins by capillary electrophoresis

Abstract

The interaction of ten natural polyphenolic compounds (chlorogenic acid, apigenin, catechin, epicatechin, flavanone, flavone, quercetin, rutin, vicenin-2 and vitexin) with human serum albumin and mixtures of human serum albumin and α(1)-acid glycoprotein under near physiological conditions is studied by capillary electrophoresis-frontal analysis. Furthermore, the binding of these polyphenolic compounds to total plasmatic proteins is evaluated using ultrafiltration and capillary electrophoresis. In spite of the relatively small differences in the chemical structures of the compounds studied, large differences were observed in their binding behaviours to plasmatic proteins. The hydrophobicity, the presence/absence of some functional groups, steric hindrance and spatial arrangement seem to be key factors in the affinity of natural polyphenols towards plasmatic proteins.

Mitochondria accumulate large amounts of quercetin: prevention of mitochondrial damage and release upon oxidation of the extramitochondrial fraction of the flavonoid

“…We immediately thought that heme-containing proteins were potentially important quercetin-binding molecules since our previous work performed in RBC provided evidence of remarkable accumulation dependent on extensive binding of the flavonoid to hemoglobin [12,[40][41][42]. Quercetin binding to hemoglobin was recently documented by fluorescence quenching as well as by absorption and circular dichroism spectroscopy [43].…”

Influence of the Galloyl Moiety in Tea Catechins on Binding Affinity for Human Serum Albumin

“…Previous research has indicated that catechins form complexes with human serum albumin (HSA), and differences in binding affinity toward HSA are believed to determine their bioavailability. Several reports using spectrofluorometry, circular dichroism, and capillary electrophoresis have indicated that green tea catechins bind to HSA (12)(13)(14). Recently, we revealed that EGCg non-covalently binds to HSA after incubation of human serum with EGCg ( 15 ).…”

Determination of liposome–buffer distribution coefficients of charged drugs by capillary electrophoresis frontal analysis

“…ACE in the frontal analysis format has primarily been used to investigate plasma protein binding of small molecules [33][34][35][36][37], and to a certain extent ligand-electrolyte interactions [37,38]. Kuroda et al used liposomes as a model of lowdensity lipoproteins to study the interactions between the drug compounds propranolol and verapamil and liposomes in the CE frontal analysis (CE-FA) format [39].…”