Quercetin inhibits hexose transport in a human diploid fibroblast.
The flavonol quercetin, a phloretin analog, inhibits transport of 2-deoxyglucose and 3-O-methylglucose in a cultured human diploid fibroblast. This inhibition is related to transport itself and not to the reported effects of flavonoids on membrane-bound ATPases. From concentration-inhibition curves at several pH's we conclude that uncharged (acid) quercetin (pK = 7.65) is the inhibitory form of the molecule (K1 = 10micron). Quercetin, unlike phloretin, is rapidly degraded in 0.1 N NaOH; the degradation products are weakly inhibitory to hexose transport.
D001693:Biological Transport, Active / Q000187:drug effects; D002478:Cells, Cultured; D003847:Deoxyglucose / Q000378:metabolism; D004171:Diploidy; D005347:Fibroblasts / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D006601:Hexoses / Q000378:metabolism*; D006801:Humans; D008757:Methylglucosides / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology*
D005419:Flavonoids; D006601:Hexoses; D008757:Methylglucosides; D003847:Deoxyglucose; D011794:Quercetin