The interaction of anthocyanins with bilitranslocase.
Bilitranslocase (TC 2.A.65.1.1) is an organic anion membrane carrier expressed at the sinusoidal domain of the liver plasma membrane and in epithelial cells of the gastric mucosa. Its substrates are sulfobromophthalein, bilirubin, and nicotinic acid. This work reports on the identification of a new class of bilitranslocase substrates, i.e., anthocyanins. Seventeen out thes 20 compounds tested behaved as competitive inhibitors of bilitranslocase transport activity (K(I)=1.4-22 microM). Their structure-activity relationship reveals that mono- and di-glucosyl anthocyanins, the anthocyanin species occurring in food, are better ligands than the corresponding aglycones. Moreover, the first interaction of anthocyanins with the carrier occurs through hydrophilic moieties, such as the 3-glucosyl moiety and the B ring for the monoglucosides, through the 5-glucosyl moiety and the A ring for the diglucosides, and through either the B or the A ring for the aglycones. These findings suggest that bilitranslocase could play a role in the bioavailability of anthocyanins.
Passamonti
Sabina
S
Dipartimento di Biochimica Biofisica e Chimica delle Macromolecole, Università di Trieste, via L. Giorgeri 1, 34127 Trieste, Italy. passamon@bbcm.univ.trieste.it
Vrhovsek
Urska
U
Mattivi
Fulvio
F
D000215:Acylation; D000818:Animals; D000872:Anthocyanins / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D001665:Binding Sites; D001667:Binding, Competitive; D001682:Biological Availability; D001692:Biological Transport; D050260:Carbohydrate Metabolism; D002570:Ceruloplasmin; D016166:Free Radical Scavengers / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D005960:Glucosides / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D013329:Structure-Activity Relationship
D000872:Anthocyanins; D016166:Free Radical Scavengers; D005960:Glucosides; D008565:Membrane Proteins; D002570:Ceruloplasmin; C033838:bilitranslocase