LC-DAD-ESIMS/MS characterization of antioxidant and anticholinesterase constituents present in the active fraction from Persicaria hydropiper

Persicaria hydropiper or 'kesum' is a herb used extensively as flavoring agent in food. The antioxidant activity was evaluated by measuring the hydroperoxide production resulting from linoleic acid oxidation using ferric thiocyanate (FTC) as well as the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging ability. Moreover, inhibition activity against cholinesterase, an enzyme that responsible in several physio-pathological processes, was also determined. Identification of phytochemical constituents in the bioactive fraction of P. hydropiper was carried out by LC-DAD-ESIMS/MS technique. Fifteen compounds were identified including flavonoids, flavonoid glycosides and phenylpropanoid glycosides. Six of the compounds were isolated and their structures were elucidated in order to confirm their identities. The antioxidant and antiacetylcholinesterase activities of the isolated compounds were also evaluated.

► Fifteen compounds were identified from bioactive fraction of Persicaria hydropiper. ► Identification based on their MS/MS spectra and NMR spectroscopy. ► First report on anticholinesterase of the crude, fractions and compounds. ► Compounds 1, 6 and 10 were found to exhibit strong antioxidant activity.