Phytochemical characterization of the ethanolic extract of Kaempferia galanga rhizome for anti-oxidant activities by HPTLC and GCMS

Abstract

Background The rhizome of Kaempferia galanga (K. galanga) was collected from Meghalaya, India, and its ethanolic extract was obtained by freeze-drying or lyophilization process, which was then assessed for its in vitro anti-oxidant activity and phytochemical characterization using high-performance thin-layer chromatography (HPTLC) and gas chromatography-mass spectroscopy (GCMS). Results In vitro anti-oxidant activity analysis shows an inhibitory concentration (IC50) value of 1.824 mg/mL and 0.307 mg/mL for, α, α-diphenyl-ρ-picrylhydrazyl (DPPH) and 2, 2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays, respectively. Total polyphenol content (TPC) of 23.55 ± 0.5 mg gallic acid equivalent (GAE)/g dry weight of extract and total flavonoid content (TFC) of 100 ± 1.414 mg rutin equivalents (RE)/g dry weight of extract were found. High-performance thin-layer chromatography (HPTLC) analysis shows the best separation of bands at different retention factor (Rf) values, when employing the solvent system 2-butanol/1-propanol/water in the ratio of 3:1:1 (v/v/v). Gas chromatography-mass spectroscopy (GCMS) analysis confirms the presence and identification of various phytocompounds, with ethyl p-methoxycinnamate identified as the major active compound. Conclusion Freeze-dried ethanolic extract of K. galanga (rhizome) possesses anti-oxidant activity. Ethyl p-methoxycinnamate is present as the major bioactive component (about 94.87% of the total area composition), and since it has very important and diverse medicinal properties, a freeze-drying process (lyophilization) can be utilized for its isolation and extraction.