Abstract:Flavonoids in the leaves of Laurus nobilis were identified using liquid chromatography-quadrupole-time of flight mass spectrometry combined with comparison of the retention times and tandem mass spectrometric fragment patterns of standards or from related literature. Flavonoid contents were measured by liquid chromatography-triple quadrupole tandem mass spectrometry in multiple reaction monitoring mode. Sixteen flavonoids were detected in L. nobilis leaves, including vitexin-2-O-rhamnoside (1658.53 ± 56.9 μg/g), rutin (19,883.54 ± 494.33 μg/g), vitexin (4430.87 ± 89.72 μg/g), type-A procyanidin trimer (2281.88 ± 78.90 μg/g), epicatechin (148.10 ± 2.32 μg/g), kaempferol-3-O-rutinoside (3491.02 ± 47.98 μg/g), isorhamnetin-3-O-rutinoside (6643.78 ± 99.04 μg/g), hyperoside (11,979.66 ± 317.79 μg/g), kaempferol-7-glucoside (738.55 ± 10.86 μg/g), astragalin (508.60 ± 6.96 μg/g), quercetin-3-O-xylopyranoside (2044.22 ± 57.65 μg/g), isorhamnetin-3-O-glycosidase (2079.94 ± 76.38 μg/g), quercitrin (2079.94 ± 61.84 μg/g), kaempferol-3-O-rhamnoside (6412.37 ± 78.65 μg/g), quercetin (1629.45 ± 47.65 μg/g), and kaempferol (364.29 ± 2.84 μg/g). The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities of the extract were determined, and the results clearly demonstrated that flavonoids from L. nobilis possessed significant radical scavenging activities.
