Phytochemical screening and bioactivities of Boesenbergia rotunda / Fatin Nurafiqah Ghazali

The qualitative phytochemical screening as well as antioxidant and antibacterial activities of Boesenbergia rotunda (Zingiberaceae) have been investigated. The phytochemicals were extracted by sequential maceration using n-hexane, ethyl acetate and methanol, while phytochemical screening was performed using several chemical tests. 2,2-Diphenyl-1-picryhydrazyl and disc diffusion methods were used to determine antioxidant and antibacterial activities, respectively. Flavonoids, phenols, steroids and terpenes were found to be present in the n¬ hexane, ethyl acetate and methanol extracts. However, alkaloids, saponins, tannins were absent in all extracts. Thin layer chromatography analysis revealed that the best separation of compound for the n-hexane extract was achieved by using n-hexane:diethyl ether (3:2), while better separation of compounds in ethyl acetate extract was accomplished using n-hexane:ethyl acetate (2:3). The best solvent system for methanol extract was n-hexane:ethyl acetate (I:I ). All extracts demonstrated no DPPH radical scavenging activity at concentration of I 000 µg/mL. All extracts showed antibacterial activity towards S. aureus (10.25-I 4.50 mm) and E. coli (9.67-17.00 mm). The methanol extract exhibited the highest inhibitory activity toward S. aureus and E. coli with the inhibition zones diameter were 14.50 and 17.00 mm, respectively.