Next Article in Journal
Cerium (IV) Ammonium Nitrate (CAN) Catalyzed One-pot Synthesis of 2-Arylbenzothiazoles
Previous Article in Journal
New Withanolides from Two Varieties of Jaborosa Caulescens
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Abstract

Formation of Complexes of Flavonoids and Metals. Determination of the Stoichiometry and Stability Constants

1
PROPLAME-CONICET, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, 1428 Buenos Aires, Argentina
2
INQUIMAE, Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, 1428 Buenos Aires, Argentina
*
Author to whom correspondence should be addressed.
Molecules 2000, 5(3), 516-517; https://doi.org/10.3390/50300516
Published: 22 March 2000

Abstract

:
The complexes between some flavonoids and metals (Co(II), Cu(II), Mn(II), Mg(II), Sn(II)) have been studied by spectrophotometric methods in order to determine the stoichiometry and stability constants.

Introduction

Flavonoids are poliphenolic compounds, which are characterized by showing a variety of pharma- cological activities, e.g. antioxidant, antihelmintic, antiinflamatory, antiviral, antitumor, etc. Most of these activities are due to their ability to inhibit enzymes, such as trypsine, protein kinases, topoi- somerases.
The complex formation of these compounds and metals of the active enzyme site or complexes between certain amino acids of the active site and the metals of the medium is probably the reason of this enzymatic inhibition.
This study deals with the determination of the stoichiometry of the complexes of some flavonoids and a variety of metals (Co(II), Cu(II), Mn(II), Mg(II), Sn(II)) as well as the determination of each sta- bility constant.

Experimental

Spectrophotometric methods were used. Solutions of each flavonoid and metal salts in a molar rate (metal mols/total mols) in the range of 0.09 and 0.9 were prepared using methanol.
UV-Visible spectra for each molar rate were performed, and plotting Absorbance vs Molar rate or Initial metal concentration the exact stoichiometry of each complex was determined.

Results and discussion

Formation of species with a 1:1 (metal:ligand) stoichiometry were obtained for the flavonoids tested. The stability constant of each complex was determined.
Molecules 05 00516 i001

Acknowledgment:

The authors are indebted to CONICET (Argentine) and the Universidad de Buenos Aires for financial support.

References and Notes

  1. Phytochemistry 1986, 25(2), 383–385.
  2. Biochemical Pharmacology 1993, 46(7), 1257–1271.
  3. J. Biol. Chem. 1996, 271(4), 2262–2270.
  4. J. Nat. Prod. 1995, 58(6), 823–829.
  5. Biochem. Pharmacol. 1989, 38(10), 1617–1624.
  6. Biochem. Pharmacol. 1986, 35(14), 2345–2357.
  7. Biochem. Pharmacol. 1986, 35(2), 237–245.
  8. Biochem. Pharmacol. 1987, 36(5), 717–720.
  9. Biochem. Pharmacol. 1989, 38(17), 2859–2865.
  10. Can. J. Chem. 1991, 69, 1994–2001.

Share and Cite

MDPI and ACS Style

Barolli, M.G.; Werner, R.A.; Slep, L.D.; Pomilio, A.B. Formation of Complexes of Flavonoids and Metals. Determination of the Stoichiometry and Stability Constants. Molecules 2000, 5, 516-517. https://doi.org/10.3390/50300516

AMA Style

Barolli MG, Werner RA, Slep LD, Pomilio AB. Formation of Complexes of Flavonoids and Metals. Determination of the Stoichiometry and Stability Constants. Molecules. 2000; 5(3):516-517. https://doi.org/10.3390/50300516

Chicago/Turabian Style

Barolli, M. G., R. Alonso Werner, L. D. Slep, and A. B. Pomilio. 2000. "Formation of Complexes of Flavonoids and Metals. Determination of the Stoichiometry and Stability Constants" Molecules 5, no. 3: 516-517. https://doi.org/10.3390/50300516

Article Metrics

Back to TopTop