Back to the Top
Dear Sirs!
I'm studying the absorption mechanism of quercetin as well and I also
can't find its pKa in the literature. I would be very thankful for
this information.
Sincerely Yours
Anna Oborska
Warsaw University of Technology
Back to the Top
From: Micheal Molino
Date: Thu, 20 Sep 2001 09:58:38 -0400
To: david.-at-.boomer.org
Subject: RE: PharmPK Re: pKa and solubility of quercetin
Anna,
There is a reference to quercetin pKa in the enclosed paper. It should be
between 9.5 and 10.5. This is in accordance with the pKa of phenylic acid
(phenol), which at 250 C is 10.0
The full reference is as follows:
Comparison of LC-MS and CE-MS for the Analysis of Polyphenols in Red Wines.
G. Vanhoenacker 1,3 , A. De Villiers 2 , D. De Keukeleire 3 , and P. Sandra
1,2*
for info on the article e-mail pat.sandra.at.rug.ac.be
I hope this helps.
Regards,
Michael Molino
---
From: "Hendrickson, Howard P"
Date: Thu, 20 Sep 2001 13:09:11 -0500
To: david.at.boomer.org
Subject: RE: PharmPK Re: pKa and solubility of quercetin
The following message was posted to: PharmPK
I had problems finding a specific pKa for quercetin. I did find references
for structures similar to quercetin. The 3-OH group's pKa is about 5 and the
other phenolic groups are about 9. Be careful though, quercetin will oxidize
in the presence of oxygen. The oxidation is favored at higher pH values. I
found that 10 to 50uM was the highest concentration I could get in aqueuous
solution (pH 7.4). This was accomplished by first dissolving quercetin in
DMSO and diluting into my assay solution (liver microsomes).
PharmPK Discussion List Archive Index page
Copyright 1995-2010 David W. A. Bourne (david@boomer.org)