Biological Activities of Zn(II) and Cu(II) Complexes with Quercetin and Rutin: Antioxidant Properties and UV-Protection Capacity

The aim of this study is to determine the changes occurred in the antioxidant capacity and in the UV-protection capacity (sun protection factor-SPF) of quercetin and rutin following the chelating with two different redox-potential cations, Zn(II) and Cu(II). The complexes were obtained using an adapted method from the literature and characterized by elemental analysis, UV-Vis and IR spectroscopy. The antioxidant capacity of the obtained complexes and the ones of the ligands (rutin and quercetin) was measured by photochemiluminometry. Sun protection factor (SPF) for both ligands and the complex compounds was determined using a spectrometric method. The SFP values in all the complexes are lower than the ones of their ligands. The antioxidant capacity is higher in the case of rutin-Zn complex, rutin-Cu(II) complex and quercetin-Cu(II) complex than of the ligands ones. These three complexes have high antioxidant activity which recommends them for further work in possible therapeutic applications identification.