Investigation of a wild pear species (Pyrus elaeagnifolia subsp Elaeagnifolia Pallas) from Antalya, Turkey: polyphenol oxidase properties and anti-xanthine oxidase, anti-urease, and antioxidant activity

Abstract

Polyphenol oxidase properties and anti-xanthine oxidase, anti-urease, and antioxidant activity were investigated in Pyrus elaeagnifolia subsp. elaeagnifolia Pallas harvested from Antalya, Turkey. Optimum pH and temperature were 7.0 and 30 degrees C, respectively. Selected kinetic properties of polyphenol oxidase was evaluated.The K-m and V-max-values, using 4-methylcatechol as substrate, were calculated as 3.57 mM and 4781 U/mg protein, respectively. IC50-values ranged from 0.0036 to 4.0231 mM against sodium metabisulphite, ascorbic acid, sodium azide, and benzoic acid, while ascorbic acid was the strongest inhibitor. Aquatic extracts of the sample exhibited strong antioxidant capacity and substantial xanthine oxidase and urease inhibition, with IC50-values of 10.75 +/- 0.11 and 0.97 +/- 0.03 mg/mL, respectively.