*4.7. Fluorescence Suppression—Quenching*

The measurements were performed on a Varian spectrofluorometer (Cary Eclipse model, Agilent Technologies Inc., Santa Clara, CA, USA) by applying a wavelength of 278 nm for excitation of the collagenase, excitation and emission slits were 5 nm wide, and acquisition of emission spectra occurred in the range of 300–450 nm, with the sample compartment with a thermostat at 25, 30, and 37 ◦C. A 10 × 10 mm optical path quartz (Hellma, Mülheim, Germany) cuvette was used. To obtain spectra, 2 mL of collagenase (Sigma-Aldrich) in concentration 0.065 mg mL−<sup>1</sup> (water solution) were titrated with hesperidin solution in DMSO (0.10 mg mL−<sup>1</sup> concentration). Additions of aliquots of HSD were as follow: 0.5 μL up to 4 μL, 1.0 μL up to 50 μL, and 5 μL up to a volume of 110 μL, reaching the final concentrations of 5.68 mg mL−<sup>1</sup> of HSD in solution.
