Chemical constituent and antioxidant activity of methanol extract from Indonesian Curcuma aeruginosa roxb. rhizome

Aim: Herbal plants are widely used to promote and rehabilitate health and to prevent and cure disease. One of the herbal plants that have been used is Curcuma aeruginosa Roxb. (Zingiberaceae), which is commonly called "Temu hitam" in Indonesia. The rhizome of C. aeruginosa has been reported to possess many interesting pharmacological activities such as antioxidant, antiandrogenic, antimicrobial, antiviral for dengue fever and HIV-1, anti-inflammation, and anticancer. Methods: This study aimed to isolate the secondary metabolite from the polar fraction of the rhizome extract and evaluate its antioxidant activity. Results: The secondary metabolite was isolated using vacuum liquid, radial, column, and preparative thin-layer chromatography. Identification of the purified fraction using liquid chromatography-mass spectroscopy showed two dominant peaks on retention time of 8.19 and 12.29 min, suspected a sesquiterpene derivative and an isoflavone (chromene) derivative, respectively. Conclusion: Thus, these purified fractions had very weak antioxidant activity toward 1, 1-diphenyl-2-picrylhydrazyl assay with half maximal inhibitory concentration > 1000 ppm.