Potentiometric and Chromatographic Study of Cu(II) and Al(III) Complexes of Quercetin


ÇIKLA YILMAZ D. , Pekin M.

MARMARA PHARMACEUTICAL JOURNAL, vol.21, no.2, pp.330-337, 2017 (Journal Indexed in ESCI) identifier

  • Publication Type: Article / Article
  • Volume: 21 Issue: 2
  • Publication Date: 2017
  • Doi Number: 10.12991/marupj.300814
  • Title of Journal : MARMARA PHARMACEUTICAL JOURNAL
  • Page Numbers: pp.330-337

Abstract

In this study, the stability constants of the copper(II) and aluminium(III) complexes of quercetin were determined potentiometrically by using Calvin-Bjerrum and Irwing Rossotti methods. The protonation constants of quercetin were found: logK(1) = 11.15 +/- 0.118, logK(2) = 10.42 +/- 0.144, logK(3) = 9.44 +/- 0.162, logK(4) = 8.28 +/- 0.151. For copper complex formation constant was found by Irwing-Rossotti method: logK(1) = 19.92 +/- 0.367 and for aluminium complex complex: logK(1) = 23.02 +/- 0.459. From the results, the components of quercetin / metal complexes are given as 1/1 both copper(II) and aluminium(III). A reversed phase high pressure liquid chromatographic method was developed for the metal complexes which were prepared according to potentiometric results with the ratio quercetin / metal = 1/1. Mobile phase was 0.01 M HClO4/8.33 x 10(-5) M quercetin in Methanol (40/60), column was XTerra RP18, 5 mu m, 4.6 x 150 mm, detector was Diode Array Detector at lambda = 373 ve 421 nm (band width 4nm).