Polyphenolics composition of the leaves of Zanthoxylum bungeanum Maxim. grown in Hebei, China, and their radical scavenging activities.

High performance liquid chromatography coupled with tandem mass spectrometry with electrospray ionization and negative ion detection (HPLC-ESI-MS/MS) was used to identify the polyphenols from the leaves of a traditional vegetable and spice, Zanthoxylum bungeanum Maxim., in China by comparison of the retention times and mass spectral fragment with standard substances or related literature. A phenolic acid glucoside, two acids, and eight flavonoids were determined including vanillic acid-4-glucoside (22.75 μg/g, dry weight of leaves), quinic acid (58.58 μg/g), chlorogenic acid (2515.96 μg/g), epicatechin (77.80 μg/g), 5-feruloyquinic acid (16.63 μg/g), syringetin-3-glucoside (103.23 μg/g), rutin (89.41 μg/g), hyperoside (886.36 μg/g), quercetin-3-arabinoside (118.75 μg/g), quercitrin (645.82 μg/g), and isorhamnetin-3-glucoside (104.27 μg/g). The obtained polyphenols show good radical scavenging activities in DPPH and superoxide anion. Through the intracellular antioxidation assay, the result shows that the polyphenols could reduce the ROS in HT-29 cells without cell toxicity.