2.3.1. Hydrogen Peroxide Scavenging Activity (HPSA)

The Manolov et al. approach was used to evaluate the furan hybrid molecules' capacity to scavenge hydrogen peroxide [12].

A 43 mM solution of H2O2 was prepared in potassium phosphate buffer solution (0.2 M, pH 7.4). The analysis of the samples was carried out as follows: in test tubes, 0.6 mL H2O2 (43 mM), 1 mL sample/standard with different concentrations (20–1000 μg/mL), and 2.4 mL potassium phosphate buffer solution were mixed. The mixture was stirred and incubated in the dark for 10 min at 37 ◦C. Absorbance was measured at 230 nm with a spectrophotometer (Camspec M508, Leeds, UK) against a blank solution containing phosphate buffer and H2O2 without the sample. Ascorbic acid and quercetin were used as standards. The percentage HPSA of the samples was evaluated by comparing with a blank sample and calculated using the following formula:

$$I\_\prime\%(HPSA) = \left[\frac{A\_{blank} - (A\_{TS} - A\_{CS})}{A\_{blank}}\right] \ast 100\tag{1}$$

where *Ablank* is the absorbance of the blank sample, *ACS* is the absorbance of the control sample, and *ATS* is the absorbance of the test sample. The mean IC50 value was estimated based on three replicates by means of interpolating the graphical dependence of scavenging hydrogen peroxide on concentration.
