Complexes of Furonewguinone B
with a Cu 2+ Ion. A DFT Study
Liliana Mammino
Abstract Furonewguinone B is a prenylated acylphloroglucinol (ACPL) isolated
from Hypericum species and exhibiting antioxidant activity. Its molecule contains
a substituted furanoid ring fused to the benzene ring. The molecule has four OH
groups, two sp
2 O atoms and one ether O, which results in a high number of possible
coordination sites for a metal ion—the seven O atoms and the π bond in the prenyl
chain. Complexes of furonewguinone B with a Cu
2+ ion were calculated considering
all the conformers of the molecule and all the sites to which Cu
2+ might bind, coordinating either to individual sites or simultaneously to two geometrically suitable sites.
Calculations were performed at the DFT/B3LYP level, using the 6-31+G(d,p) basis
set for the C, O and H atoms and the LANL2DZ pseudopotential for the Cu
2+ ion. The
complexes’ relative energies, molecule-ion affinities and other computed molecular
properties are analysed in terms of the binding sites of the ion. The effects of complexation on the intramolecular hydrogen bonds and on the other characteristics of
the conformers are also analysed. The results highlight the preferred binding sites of
the Cu
2+ ion and show that its charge is reduced effectively in the complexes. Comparison with previously-calculated complexes of other antioxidant ACPLs highlight
similarities and differences related to the structural features of the molecules.
Keywords Acylphloroglucinols · Antioxidants · Effects of complexation with a
metal ion on molecular properties · Intramolecular hydrogen bonding ·
Molecule-metal ion affinity in complexes · Phenolic compounds · Reducing ability
Electronic supplementary material The online version of this chapter
(https://doi.org/10.1007/978-3-030-34941-7_9) contains supplementary material, which is
available to authorized users.
L. Mammino (B)
School of Mathematical and Natural Sciences, University of Venda, Thohoyandou, South Africa
© Springer Nature Switzerland AG 2020
L. Mammino et al. (eds.), Advances in Quantum Systems in Chemistry,
Physics, and Biology, Progress in Theoretical Chemistry and Physics 32,
https://doi.org/10.1007/978-3-030-34941-7_9
159
with a Cu 2+ Ion. A DFT Study
Liliana Mammino
Abstract Furonewguinone B is a prenylated acylphloroglucinol (ACPL) isolated
from Hypericum species and exhibiting antioxidant activity. Its molecule contains
a substituted furanoid ring fused to the benzene ring. The molecule has four OH
groups, two sp
2 O atoms and one ether O, which results in a high number of possible
coordination sites for a metal ion—the seven O atoms and the π bond in the prenyl
chain. Complexes of furonewguinone B with a Cu
2+ ion were calculated considering
all the conformers of the molecule and all the sites to which Cu
2+ might bind, coordinating either to individual sites or simultaneously to two geometrically suitable sites.
Calculations were performed at the DFT/B3LYP level, using the 6-31+G(d,p) basis
set for the C, O and H atoms and the LANL2DZ pseudopotential for the Cu
2+ ion. The
complexes’ relative energies, molecule-ion affinities and other computed molecular
properties are analysed in terms of the binding sites of the ion. The effects of complexation on the intramolecular hydrogen bonds and on the other characteristics of
the conformers are also analysed. The results highlight the preferred binding sites of
the Cu
2+ ion and show that its charge is reduced effectively in the complexes. Comparison with previously-calculated complexes of other antioxidant ACPLs highlight
similarities and differences related to the structural features of the molecules.
Keywords Acylphloroglucinols · Antioxidants · Effects of complexation with a
metal ion on molecular properties · Intramolecular hydrogen bonding ·
Molecule-metal ion affinity in complexes · Phenolic compounds · Reducing ability
Electronic supplementary material The online version of this chapter
(https://doi.org/10.1007/978-3-030-34941-7_9) contains supplementary material, which is
available to authorized users.
L. Mammino (B)
School of Mathematical and Natural Sciences, University of Venda, Thohoyandou, South Africa
© Springer Nature Switzerland AG 2020
L. Mammino et al. (eds.), Advances in Quantum Systems in Chemistry,
Physics, and Biology, Progress in Theoretical Chemistry and Physics 32,
https://doi.org/10.1007/978-3-030-34941-7_9
159