Exploring the oxidation and iron binding profile of a cyclodextrin encapsulated quercetin complex unveiled a controlled complex dissociation through a chemical stimulus

0490766 - ÚFCH JH 2019 RIV NL eng J - Článek v odborném periodiku
Diamantis, D. A. - Ramešová, Šárka - Chatzigiannis, Ch. M. - Degano, I. - Gerogianni, P. S. - Karadima, K. E. - Perikleous, S. - Rekkas, D. - Gerothanassis, I. P. - Galaris, D. - Mavromoustakos, T. - Valsami, G. - Sokolová, Romana - Tzakos, A. G.
Exploring the oxidation and iron binding profile of a cyclodextrin encapsulated quercetin complex unveiled a controlled complex dissociation through a chemical stimulus.
Biochimica et Biophysica Acta-General Subjects. Roč. 1862, č. 9 (2018), s. 1913-1924. ISSN 0304-4165. E-ISSN 1872-8006
Institucionální podpora: RVO:61388955
Klíčová slova: antioxidants * metal complexes * oxidation mechanism
Obor OECD: Analytical chemistry
Impakt faktor: 3.681, rok: 2018

Background: Flavonoids possess a rich polypharmacological profile and their biological role is linked to their
oxidation state protecting DNA from oxidative stress damage. However, their bioavailability is hampered due to
their poor aqueous solubility. This can be surpassed through encapsulation to supramolecular carriers as cyclodextrin
(CD). A quercetin- 2HP-β-CD complex has been formerly reported by us. However, once the flavonoid
is in its 2HP-β-CD encapsulated state its oxidation potential, its decomplexation mechanism, its potential to
protect DNA damage from oxidative stress remained elusive. To unveil this, an array of biophysical techniques
was used.
Methods: The quercetin-2HP-β-CD complex was evaluated through solubility and dissolution experiments,
electrochemical and spectroelectrochemical studies (Cyclic Voltammetry), UV–Vis spectroscopy, HPLC-ESI-MS/
MS and HPLC-DAD, fluorescence spectroscopy, NMR Spectroscopy, theoretical calculations (density functional
theory (DFT)) and biological evaluation of the protection offered against H2O2-induced DNA damage.
Results: Encapsulation of quercetin inside the supramolecule's cavity enhanced its solubility and retained its
oxidation profile. Although the protective ability of the quercetin-2HP-β-CD complex against H2O2 was diminished,
iron serves as a chemical stimulus to dissociate the complex and release quercetin.
Conclusions: We found that in a quercetin-2HP-β-CD inclusion complex quercetin retains its oxidation profile
similarly to its native state, while iron can operate as a chemical stimulus to release quercetin from its host
cavity.
General significance: The oxidation profile of a natural product once it is encapsulated in a supramolecular carrier
was unveiled as also it was discovered that decomplexation can be triggered by a chemical stimilus.
Trvalý link: http://hdl.handle.net/11104/0284917