Phytochemicals from root barks of garcinia cowa roxb. and antioxidant activity

Abstract

Garcinia cowa Roxb (Cha-muang) is one of the well-known medicinal plants belong to the Clusiaceae family. Many parts of G. cowa have been investigated for their interesting phytochemicals. In this work, the root barks of G. cowa were extracted with EtOAc and then with MeOH, and the extracts were fractionated and purified by column chromatographic techniques. From the MeOH extract obtained, four biflavonoids were identified as (+) volkensiflavone (BIF1), (+) morelloflavone (BIF2), (+) spicataside (BIF3), and (+) fukugiside (BIF4). The structure of all isolated compounds was elucidated by spectroscopic techniques, especially IR, 1D- and 2D- NMR including by comparison of their spectroscopic data with those reported in the literature. The antioxidant activity of the extracts and the isolated compounds were tested using DPPH radical scavenging assay. The isolated compounds BIF2 and BIF4 as well as the MeOH extract exhibited strong activity with IC50 values of 8.85, 19.65, and 47.40 μg/mL, respectively.

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