Electronic Spectroscopies Combined with Quantum Chemistry Calculations: Study of the Interactions of 3-Hydroxyflavone with Copper Ions

Abstract

The current study aims at obtaining a better understanding of the mechanisms involved in the complexation of copper ions by 3-hydroxyflavone (3HF), which is one of the most studied compounds of the flavonoid family. To achieve this goal, quantum chemistry calculations combined with electronic spectroscopies, including absorption, fluorescence emission, and excitation, have been used. The formation of successive complexes of stoichiometry (metal/ligand) 1:2, 1:1, and 3:2 has been highlighted. Even under acidic conditions (pH = 4.0), the α-hydroxy-keto function of the molecule presents a high complexing power with regard to copper ions, insofar as a stable complex of 1:2 stoichiometry is obtained with a large conditional stability constant (log β = 8.7). The formation of this predominant species induces a quenching of the dual fluorescence of 3HF, whereas the second complex of stoichiometry 1:1 presents a fluorescence emission.

An Overview of Pharmacological Activities and Beneficial Effects of 3‐Hydroxyflavone

“…Synthesis of new complexes of hydroxyflavones allows for improvement biological properties, stability, water solubility, hydrophilicity, bioavailability comparing with the parent hydroxyflavones. [44] Evaluated the 3-hydroxyflavone and structural analogues that differentially activate the pregnane X receptor (PXR; NR1I2) implications for inflammatory bowel disease. In LS180 human colon adenocarcinoma cells, 3-hydroxyflavone, quercetin, and tamarixetin increased CYP3A4, CYP3A5, and ABCB1 mRNA expression, whereas galangin and isorhamnetin increased CYP3A4 and ABCB1 but not CYP3A5 mRNA expression.…”

“…Synthesis of new complexes of hydroxyflavones allows for improvement biological properties, stability, water solubility, hydrophilicity, bioavailability comparing with the parent hydroxyflavones. [ 44 ]…”

Orthogonal effect of exchange and correlation parameters in density functional theory to compute geometric and spectroscopic quantities

“…In this article, the case of two different flavonols (morin and quercetin, Figure 1) will be highlighted. Indeed, these naturally occurring molecules have been studied for several decades in our group, and possess interesting characteristics for this study 11–13 …”