The flavonoid profiles in different tissue parts of Shatianyu (Citrus grandis L. Osbeck) and their in vitro bioactivity

The profiles and bioactivity of flavonoids in the different tissue parts of Shatianyu (Citrus grandis L. Osbeck), including flavedo, albedo, septum, pulp and seed, were investigated in the present study. Fourteen flavonoids were identified by UHPLC-ESI-MS/MS using a multiple reaction monitoring (MRM) mode. Melitidin, naringin and bergamjuicin were the main flavonoids in flavedo, albedo, septum and pulp, while naringin, melitidin and neoeriocitrin were the major flavonoids in seed. In addition, cigranoside C, D, E, F, bergamjuicin and neoeriocitrin, which were isolated from Shatianyu pulp with new structure in our previous study, were detected in all tissue parts and took up 8.9%–37.2% of the total contents of detected flavonoids. Besides strong antioxidant activity, the flavedo and seed of Shatianyu showed potent pancreatic lipase inhibitory activity with IC50 value of 3.9 and 23.1 μg GAE/mL, respectively. Thus, Shatianyu is natural source of flavonoids and possesses potential for application in anti-obesity nutraceutical food.