chaga mushroom (inonotus obliquus) grows on birch trees found mainly in temperate regions like canada, northern united states and siberia. it contains phytochemicals such as betulin and betulinic acid, which are a pentacyclic triterpenoid along with several bioactive compounds such as β-glucans and phenolic antioxidants. the aim of this study was to enhance betulin (bn) and betulinic acid (ba) extraction from the fungi. it was determined that pre-treatment by water soaking for four days was required before solvent extraction is carried out. following this extraction using solvents, ultrasonic treatment was done. ultrasonication dramatically increased betulin and betulinic acid yield. there was considerable variance in the quantity of these products in chaga obtained from different commercial sources. quantitative analysis for betulinic acid using high performance liquid chromatography (hplc) method had to be developed. it was demonstrated that pure betulinic acid had significant effect on cell viability and reduction of oxidative stress. however, the combined effect of all the components of the bioactive extract (total phenolics found to be 201mg gallic acid / 100g of dry sample) was found to be much higher.