C-Isoprenylation of flavonoids enhances binding affinity toward P-glycoprotein and modulation of cancer cell chemoresistance.
Previous studies have shown that flavones bind to P-glycoprotein (Pgp) with higher affinity than isoflavones, flavanones, and glycosylated derivatives. In the present work, a series of C- or O-substituted hydrophobic derivatives of chrysin were synthesized to further investigate structural requirements of the A ring toward Pgp modulation. Increasing hydrophobicity at either position 6, 8, or 7 increased the affinity of in vitro binding to a purified cytosolic domain of Pgp, but only benzyl and 3,3-dimethylallyl C-substitution produced a high maximal quenching of the protein intrinsic fluorescence. Inhibition of membrane Pgp within leukemic cells, characterized by intracellular drug accumulation, was specifically produced by isoprenylated derivatives, with 8-(3,3-dimethylallyl)chrysin being even more efficient than the commonly used cyclosporin A.
Laboratoire des Produits Naturels, CNRS-UMR 5013, UFR de Chimie-Biochimie, Université Claude Bernard Lyon 1, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
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G
Comte
J B
JB
Daskiewicz
C
C
Bayet
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G
Conseil
A
A
Viornery-Vanier
C
C
Dumontet
A
A
Di Pietro
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D
Barron
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005419:Flavonoids / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
C423345:8-(3,3-dimethylallyl)chrysin; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D005419:Flavonoids