Novel Synthesis of 3,3′-Dihydroxyflavone and Apparent Formation Constants of Flavonoid−Ga(III) Complexes
Flavonoids are a wide variety of polyphenolic compounds. They have many biological properties. They also exhibit a metallic ion complexation capacity, which is important since it has been found that biological properties these ligands present can be enhanced when complexation occurs. In this work fo...
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Published in | Journal of chemical and engineering data Vol. 55; no. 9; pp. 3080 - 3083 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Chemical Society
09.09.2010
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Subjects | |
Online Access | Get full text |
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Summary: | Flavonoids are a wide variety of polyphenolic compounds. They have many biological properties. They also exhibit a metallic ion complexation capacity, which is important since it has been found that biological properties these ligands present can be enhanced when complexation occurs. In this work four flavonoid−Ga(III) complexes were studied: 2′,4′,3-trihydroxychalcone−Ga(III), 2′,3-dihydroxychalcone−Ga(III), 3,7,3′-trihydroxyflavone−Ga(III), and 3,3′-dihydroxyflavone−Ga(III). All ligands were synthesized by our working group, contributing a novel, cheaper, and more simple way to obtain 3,3′-dihydroxyflavone. The stoichiometry of the complexes was determined using the Yoe−Jones method. Both chalcone−Ga(III) complexes presented 1:1 L:M stoichiometry; meanwhile flavone−Ga(III) complexes presented 2:1 L:M stoichiometry. The pK values were determined by means of a spectrophotometric method. Values obtained were: 2′,4′,3-trihydroxychalcone−Ga(III), pK = 4.35 ± 0.38; 2′,3-dihydroxychalcone−Ga(III), pK = 3.40 ± 0.17; 3,7,3′-trihydroxyflavone−Ga(III), pK = 7.74 ± 0.19; and 3,3′-dihydroxyflavone−Ga(III), pK = 8.46 ± 0.27. |
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ISSN: | 0021-9568 1520-5134 |
DOI: | 10.1021/je901091f |