Certain plants are rich sources of intermediates used in the production of drugs. For e.g., plant saponins such as Dioscin (from Dioscorea tubers) can be extracted and altered chemically to produce sapogenins (diosgenin) required to manufacture medicinally important steroids. Steroidal saponins are of great pharmaceutical importance because of their relationship to compounds such as sex hormones, cortisone, diuretic steroids, vitamin D and cardiac glycosides. Some are used as starting material for the synthesis of these compounds. The primary processing of parts containing the intermediates could be carried out in the country of origin thus retaining some value of the resource material. For example, diosgenin and hecogenin (from Sisal) used in the production of steroids can be commercially produced in the countries of origin where there are steady supplies of sufficient raw materials. So far more than 4,000 plant species have been investigated resulting in the identification of some 30 naturally occurring steroid sapogenins many of which could provide valuable source materials for steroid compounds.