Method Development and Validation for Simultaneous Determination of Six Flavonoids in Rat Eyes after Oral Administration of Diospyros kaki Leaves Extract by UPLC-MS/MS.

A robust UPLC-MS/MS technique was proven effective for simultaneous characterization of six flavonoids including quercetin-3-O-beta-galactoside (Q3GAL), quercetin-3-O-beta-glucoside (Q3GLU), quercetin-3-(2-galloylglucoside) (Q3GG), kaempferol-3-O-beta-galactoside (K3GAL), kaempferol-3-O-beta-glucoside (K3GLU), and kaempferol-3-(2-galloylglucoside) (K3GG) in rat eyes. By investigation of corresponding validation parameters (linearity, selectivity, precision, accuracy, matrix effect, extraction recovery, and stability), the method was verified to be within current acceptable criteria. Thereafter, the validated method enabled quantification of the six compounds successful in rat eyes after oral administration of ethanol extract diospyros kaki (EEDK) at 0, 3, 15, 35, 60, 120 min.