Antioxidant Potential of Ethyl Acetate Fractionate from Rhynchostylis retusa (L.) Blume

Abstract: - The escalation prevalence of degenerative diseases is closely related to excessive exposure toward free radicals, can bring about oxidative stress. The roots of the orchid tail may contain novel bioactive sources that act as radical scavengers. The purpose of this study was to find out the antioxidant potential of foxtail orchid roots (Rhynchostylis retusa (L.) Blume). The method utilized to identify new antioxidant potential using bioassay-guided fractionation. The root simplicial powder was extracted with methanol and then partitioned into n-hexane, ethyl acetate, dichloromethane, and water. The antioxidant activity exhibited that the ethyl acetate extract had IC₅₀ value 33.47 µg/mL compared to the n-hexane, DCM, methanol, and water extracts. Then fractionated using colum chromatography led to collect fraction A with IC₅₀ value; 298,74 µg/mL, fraction B; IC₅₀ value 103.73 µg/mL and fraction C; IC₅₀ value 45.41 µg/mL. The fraction C showed highest antioxidant activity compared to fraction A and B which contained tannin and phenolic may have a new lead compound for the development of antioxidants with a novel mechanism of action as an alternative raw material for phytopharmaceuticals.