Bioactive Compounds in the Flora of Belarus. 2. Astragalin, an Effective Protector of Catalase from Ultrasonic Inactivation in Aqueous Solutions

摘要

The kinetics of catalase decomposition of H_2O_2 (50 mM) inhibited by the flavonolic glycoside astragalin (1) from the aerial part of Gymnocarpium dryopteris were studied. 1 (0.3-30 M) is a strong inhibitor of the catalase process and was tested as a catalase (CAT) protector from ultrasonic activation at 45°C by treatment of enzyme solutions (1.2 nM) in phosphate buffer (7.5 mM) at pH 5.5 with low-frequency ultrasound (US, 27 kHz) at initial specific power 60 W/cm~2. 1 inhibited US-inactivation of CAT according to the rate constants for US-inactivation of CAT in the presence of 1 with and without inhibitor. 1 at concentrations of 1.0 and 20.0 μM decreases US-inactivation up to 22.3 and 19.5% of the initial level. The useful properties and effectiveness of 1 are better than the synthetic inhibitors-antioxidants propylgallate and 4-t-butylpyrocatechin.