Abstract
Background: Quercetin (Qur), a potent antioxidant flavonoid have been reported with wide applications in cardiovascular and cerebral ischemic diseases however Qur is prone to degradation in different stress conditions i.e. oxidation, alkaline and acidic medium, photodegradation under UV-light as well as thermal and enzymatic degradation by intestinal bacteria.
Objective: The aim of current research is; to study Qur degradation under different stress conditions i.e. oxidation, alkaline and acidic medium and photodegradation under UV-light, to develop and validate a sensitive ultra-high pressure liquid chromatography (UHPLC-MS/MS) method for Qur estimation after different stress conditions as well as in rat brain homogenate and plasma.
Method: The estimation study was performed on Waters ACQUITY UPLCTM with chromatographic conditions set as; column: BEH C-18 with dimensions i.e. 2.1 mm x 100 mm, 1.7 mu m particle size, mobile phase: Acetonitrile: 2mM Ammonium Acetate: Formic Acid (90: 10: 0.01 v/v/v) with a flow rate of 0.20 mL/min.
Results: The result showed, transitions for Qur and Internal Standard (IS) Rutin (RT) at m/z 301.0872/151.0309 and 609.2109/299.1203, respectively alongwith a linear dynamic range i.e. 1.00 ng mL(-1) to 2000.0 ng mL(-1)(r(2) 0.999 +/- 0.0001), lower limit of quantification (LLOQ) i.e. 0.054 ng/mL and lower limit of detection (LLOD) with 0.017 ng/mL for Qur. Furthermore, the stability order observed following Qur degradation kinetics was as; alkaline medium (t(1/2), 106.28 h(-1); t(0.9), 17.38 h(-1)) > acidic medium (t(1/2) 258.32 h(-1); t(0.9) 40.32 h(-1)) > oxidative medium (t(1/2), 29.32 h(-1); t(0.9) 5.68 h(-1)).
Conclusion: The developed UHPLC-MS/MS method exhibited a successful application in order to study degradation and pharmacokinetic studies in Wistar rat brain homogenate whereby an acceptable precision alongwith adequate sensitivity and accuracy was revealed.