Screening, determination and quantification of major antioxidants from Balanophora laxiflora flowers

In this study, antioxidant phytochemicals of Balanophora laxiflora flowers were detected by online HPLC–DPPH method. Accordingly, five phytochemicals including 1-O-(E)-caffeoyl-β-d-glucopyranose (1), 1-O-(E)-p-coumaroyl-β-d-glucopyranose (2), caffeic acid (3), 1,3-di-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-β-d-glucopyranose (4), and 1-O-(E)-caffeoyl-4,6-(S)-hexahydroxydiphenoyl-β-d-glucopyranose (5) were isolated using the developed screening method. Of these, compounds 1 and 5 were found to be major bioactive phytochemicals, and their contents were determined to be 10.8 mg and 9.5 mg per gramme of crude extract, respectively. In addition, compared with (+)-catechin, a well-known antioxidant, compounds 4 and 5 exhibited stronger DPPH radical and superoxide radical scavenging activities than (+)-catechin. These results demonstrated that the flower extracts of B. laxiflora have excellent antioxidant activities and thus have great potential as a source for natural health products.