Quantification of total polyphenols and flavonoids, antioxidant activity, and Sinensetin and Imperatorin contents of Imperata cylindrica root ethanol extract

Introduction: Imperata cylindrica, commonly known as cogon grass, is currently widely distributed and used as a medicinal plant. The major compounds that have been isolated and identified are polyphenols and flavonoids, which have many biological activities such as antioxidant, and anticancer. Polyphenols and flavonoids are mostly found in the roots and leaves. This study aimed to perform phytochemical screening on I. cylindrica root ethanol extract from Sragen, Central Java, Indonesia and determine the total polyphenol, flavonoid, antioxidant activity and quantify Sinensetin and Imperatorin contents of the extract. Method: Quantification of all parameters were measured using visible spectrophotometric methods. Total polyphenol, total flavonoid contents, as well as antioxidant activity were measured using Folin-Ciocalteu reagent, aluminum chloride reagent, and 1,1-diphenyl-2-picrylhydrazyl, respectively, and quantification of Sinensetin and Imperatorin were measured using High Performance Liquid Chromatography. Results: I cylindrica root ethanol extract had a total polyphenol content of 1.109% gallic acid equivalent, total flavonoid content of 0.1% quercetin equivalent, and antioxidant activity IC₅₀ 824.30 μg/ml. Sinensetin and Imperatorin were also identified in Fractions 1 to 11 with concentrations of 0.0157 and 0.0178 mg/kg extract, respectively. Conclusion: I. cylindrica root ethanol extract from Sragen had active phytochemical compounds of polyphenols, flavonoids, and antioxidants as well as Sinensetin and Imperatorin.