Screening of Dioscorea Species for Diosgenin from Southern Western Ghats of India

Dioscorea deltoidea Wall. is the major species exploited in India for diosgenin obtained from rhizomes. The natural stock of D. deltoidea being exhausted due to large-scale collection from forest areas and very poor rate of regeneration, leads to apprehensions that this important raw material may completely be lost to the industry if steps to conserve the stocks are not taken up immediately. Preliminary screening of different species locally available to identify new sources of diosgenin identified leaf samples to show presence of diosgenin in all the twelve species while tuber samples of only 4 species viz., Dioscorea hispida, D. hamiltonii, D. spicata and D. pubera revealed its presence. Of these, the maximum diosgenin yield was recorded in D. pubera (1220 μg/g d. wt.) followed by D. spicata (305 μg/g d. wt.), D. hispida (57 μg/g d. wt) and D. hamiltonii (3 μg/g d. wt.).