Simultaneous determination of five bioactive constituents in fruit rind extracts of Garcinia lanceifolia using a validated UHPLC-PDA method and evaluation of antioxidant activity

Xanthones and polyisoprenylated benzophenones found in Garcinia species are groups of secondary metabolites with a wide range of bioactivities. Three xanthones namely α-mangostin, β-mangostin, γ-mangostin and two polyisoprenylated benzophenone namely xanthochymol and isoxanthochymol were identified and quantified in the extracts prepared from fruit rinds of G. lanceifolia using a validated UHPLC-PDA method. Total phenolic content of extracts prepared from G. lanceifolia fruit rinds with solvents of varying polarity was determined by the Folin-Ciocalteu method. These extracts were also evaluated for their antioxidant potential using three different in vitro assays namely DPPH free radical, ABTS cation radical and reducing power. α-mangostin was not quantified in hexane and chloroform extracts. β-mangostin could not get quantified in hexane extract. γ-mangostin was not detected in any of the six extracts. The maximum content of xanthochymol (289.26 ± 0.31 mg/g) was detected in hexane extract. Isoxanthochymol content (9.91 ± 0.01 mg/g) was maximum in hexane extract and it was followed by chloroform extract (2.67 ± 0.01 mg/g). The highest total phenolic content was recorded for hexane extract (18.60 ± 1.95 mg/g GAE). In vitro assays established that G. lanceifolia extracts exhibited significant antioxidant activity.