Kinetic study on the inhibition of xanthine oxidase by acylated derivatives of flavonoids synthesised enzymatically

• Published in: Journal of Enzyme Inhibition and Medicinal Chemistry
• Main Authors: Maria Elisa Melo Branco de Araújo, Yollanda Edwirges Moreira Franco, Thiago Grando Alberto, Marcia Cristina Fernandes Messias, Camila Wielewski Leme, Alexandra Christine Helena Frankland Sawaya, Patricia de Oliveira Carvalho
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis Group 2017
• Subjects: Acylation; lipase; flavonoids; xanthine oxidase; Therapeutics. Pharmacology; RM1-950; Antarc*; Antarctica
• Online Access: https://doi.org/10.1080/14756366.2017.1347165; https://doaj.org/article/6bfaba307fe74baea7f68e4664d062ac

Studies have reported that flavonoids inhibit xanthine oxidase (XO) activity; however, poor solubility and stability in lipophilic media limit their bioavailability and applications. This study evaluated the kinetic parameters of XO inhibition and partition coefficients of flavonoid esters biosynthesised from hesperidin, naringin, and rutin via enzymatic acylation with hexanoic, octanoic, decanoic, lauric, and oleic acids catalysed by Candida antarctica lipase B (CALB). Quantitative determination by ultra-high performance liquid chromatography–mass spectrometry (UHPLC–MS) showed higher conversion yields (%) for naringin and rutin esters using acyl donors with 8C and 10C. Rutin decanoate had higher partition coefficients (0.95), and naringin octanoate and naringin decanoate showed greater inhibitory effects on XO (IC50 of 110.35 and 117.51 μM, respectively). Kinetic analysis showed significant differences (p < .05) between the flavonoids before and after acylation regarding Km values, whereas the values for Vmax were the same, implying the competitive nature of XO inhibition.