Comparative spectrophotometric determination of 3-hydroxyflavone based on zinc and aluminium complexes and their antioxidative profiles

Abstract

Abstract Flavonoids, as plant-derived compounds, were essential active components in traditional medicine for centuries. Their potential or confirmed effects include antiviral, antimutagenic, antiinflammatory, antibacterial, vasodilatory, and anticancer properties. The promotion of a plantbased diet, along with the benefits of consuming flavonoids, has recently become increasingly attractive. 3-Hydroxyflavone (3HF) is the structural spine of flavonols, an important subgroup of flavonoids. Although 3HF itself does not exist in plants per se, it exerts many of its effects because of its characteristics that allow it to prevent free radical generation. This work is focused on the characterization of 3HF complexes with zinc(II) and aluminium(III) ions (Zn-3HF and Al-3HF, respectively). Besides this, a simple, fast, and low-priced spectrophotometric method for 3HF determination, with very low LOD and LOQ, based on Zn-3HF and Al-3HF formation, was established. A slight advantage is given to the modification with Al3+ ion on pH 4.91, due to very low LOD and LOQ values of 1.83×10-7 molL-1 , and 5.50×10-7 molL-1 , respectively, and a high correlation coefficient, R =0.99986. Furthermore, the antioxidant ability of Zn-3HF, Al-3HF, and parent 3HF was examined by the ABTS and DPPH tests. They brought the Zn-3HF complex to the fore as a potential antioxidative agent.

Flavonoidi, jedinjenja biljnog porekla, vekovima su bili veoma važne aktivne komponente u tradicionalnoj medicini. Veliki broj njihovih potencijalnih ili već potvrđenih efekata uključuje antivirusna, antimutagena, antiinflamatorna, antibakterijska, vazodilatatorna i antikancerogena svojstva. Promovisanje biljne ishrane, uz isticanje koristi konzumiranja flavonoida, u današnje vreme postalo je sve privlačnije. 3-Hidroksiflavon (3HF) je strukturni stub svih flavonola, važne klase flavonoida. Iako sam 3HF ne postoji u biljkama per se, on ispoljava mnoge svoje efekte zahvaljujući osobini da sprečava stvaranja slobodnih radikala. Ovaj rad je fokusiran na karakterizaciju kompleksa 3HF sa jonima cinka(II) i aluminijuma(III) (Zn-3HF i Al-3HF, respektivno). Izvršena je karakterizacija ovih kompleksa i razvijena brza i pristupačna metoda za spektrofotometrijsko određivanje 3HF, na osnovu formiranja kompleksa Zn-3HF i Al-3HF, sa veoma niskim vrednostima LOD i LOQ. Mala prednost je data modifikaciji sa Al3+ na pH 4,91 zbog izuzetno niskih vrednosti LOD i LOQ, 1,83×10-7 mol L-1 , odnosno 5,50×10-7 mol L-1 , kao i visokog koeficijenta korelacije, R=0,99986. Pored toga, antioksidativni kapaciteti sintetizovanih kompleksa Zn-3HF i Al-3HF, kao i samog 3HF, ispitani su DPPH i ABTS testovima i doveli su Zn-3HF kompleks u prvi plan za dalja ispitivanja kao potencijalnog antioksidativnog agensa.