Quercetin solubilisation in bile salts: A comparison with sodium dodecyl sulphate.
To understand the bioaccessibility of the flavonoid quercetin we studied its interaction with bile salt micelles. The environmental sensitivity of quercetin's UV-visible absorption spectrum gave information about quercetin partitioning. Two quercetin absorption peaks gave complementary information: Peak A (240-280nm) on the intermicellar phase and Peak B (340-440nm) on the micellar phase. Thus, by altering pH, we showed that only non-ionised quercetin partitions into micelles. We validated our interpretation by studying quercetin's interaction with SDS micelles. Pyrene fluorescence and the quercetin UV-visible spectra show that the adsorption site for pyrene and quercetin in bile salt micelles is more hydrophobic than that for SDS micelles. Also, both quercetin and pyrene reported a higher critical micelle concentration for bile salts than for SDS. Our method of using a flavonoid as an intrinsic probe, is generally applicable to other lipophilic bioactives, whenever they have observable environmental dependent properties.
Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK. Electronic address: maria.buchweitz@f03.uni-stuttgart.de.
Maria
M
Buchweitz
Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK. Electronic address: paul.kroon@ifr.ac.uk.
Paul A
PA
Kroon
Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK. Electronic address: gillian.rich@ifr.ac.uk.
Gillian T
GT
Rich
Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK. Electronic address: peter.wilde@ifr.ac.uk.
Peter J
PJ
Wilde
D001647:Bile Acids and Salts / Q000032:analysis / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008823:Micelles; D011794:Quercetin / Q000032:analysis / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000032:analysis / Q000737:chemistry*; D012995:Solubility
D001647:Bile Acids and Salts; D008823:Micelles; D012967:Sodium Dodecyl Sulfate; D011794:Quercetin
Bioavailability; Micelles; Pyrene (PubChem CID: 104853); Pyrene fluorescence; Quercetin (PubChem CID: 5280804); Quercetin’s pK(a1); Sodium dodecyl sulphate (PubChem CID: 3423265); Sodium glycodeoxycholate (PubChem CID: 3035026); Sodium taurocholate (PubChem CID: 3035026); UV–visible spectra