Interaction of antioxidant biobased epicatechin conjugates with biomembrane models.
(-)-Epicatechin conjugates with sulfur-containing moieties are strong free radical scavengers with cell-protecting activities, which may be in part modulated by their capacity to bind to biological membranes. We present here a study of the interaction of these conjugates with membrane models such as multilamellar vesicles and a phospholipid-coated silica column (immobilized artificial membrane), monitored by differential scanning calorimetry and high-performance liquid chromatography, respectively. The nonpolyphenolic moiety significantly influenced the membrane behavior of the whole molecules. Bulky and hydrophobic conjugates clearly interacted with the phospholipids and may have a tendency to penetrate into the hydrophobic core of the vesicles. In contrast, the smaller cationic 4beta-(2-aminoethylthio)epicatechin may be located at the outer interface of the lipid membrane. The outcomes from both experimental set-ups were in good agreement. The differences detected in the biological activities of the conjugates may be explained in part by their tendency to penetrate the cell membrane.
Lazaro
Elisabet
E
Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona, Spain.
Castillo
José A
JA
Rafols
Clara
C
Rosés
Martí
M
Clapés
Pere
P
Torres
Josep Lluís
JL
D000975:Antioxidants / Q000378:metabolism*; D002152:Calorimetry, Differential Scanning; D002392:Catechin / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D008081:Liposomes / Q000378:metabolism; D008567:Membranes, Artificial; D010743:Phospholipids / Q000378:metabolism
D000975:Antioxidants; D008081:Liposomes; D008567:Membranes, Artificial; D010743:Phospholipids; D002392:Catechin