of aqueous turmeric extract peak ii was pooled concentrated and dialyzed against double distilled water at 4 u00b0 c using 2 kda cut off dialysis membrane for 74 hrs sds page showed the approximate molecular weight of the protein is 8 000 daltons the antioxidant activity was done by tbars and hydroxy radical scavenging assay compared to standard antioxidant like bha curcumin and u03b1 tocopherol as positive controls cell viability test by tryphan blue exclusion method was done to test the toxicity of arishinin a exemplary separation of protein by column chromatography using sephadex g 50 is depicted in fig1 the quantification of water soluble antioxidant polypeptide arishinin isolated by the process described in examples 1 to 4 as depicted in table 1 above was determined by the following methods protein estimation was done by bradford 39 s method bradford m m 1976 analytical biochem 7 248 254 with an absorption maximum at 595 nm and results shown in table 1 the antioxidant activity of arishinin was evaluated by thio barbituric acid reactive substance tbars shimasaki h et al 1984 biochem biophys acta 792 123 129 and deoxyribose method hydroxyl radical scavenging assay halliwell b et al 1981 methods of biochemical sciences 33 59 90 with absorption maximum at 535 nm by using bha alpha tocopherol and curcumin as standard antioxidants the antioxidant activity of arishinin is shown in table 2 cell viability test by tryphan blue exclusion method phillips h j 1973 kruse p f patterson m k eds pp 406 408 was done to check the toxicity of arishinin and experiment showed that arishinin was not toxic arishinin at 80 nm dose gives 90 inhibition of reactive oxygen species since arishinin is.