Tubers of many of the dioscoreas have long been used for food, as they are rich in starch. These yams are considered famine foods consumed in times of scarcity. The species is considered a medicinal plant of major importance in higher elevation regions of Nepal, Bhutan, India, Pakistan and southwestern China. The plant is used…

Dioscoreas are herbaceous, climbing, vine-like plants, the tuber being totally buried or sometimes protruding from the ground. Tubers weigh upto 5 kg with 40- to 50-kg tubers being recorded in some species. Drug material is obtained from both wild and cultivated plants with plants collected from the wild having been exploited considerably more than cultivated…

According to species, tubers yield 1% to 8% of total sapogenins, the principal of which is diosgenin with small quantities of the 25β-epimer yamogenin. While D. composita may contain 4% to 6% total saponins, D. floribunda has 6% to 8% diosgenin. Disogenin is present as a dioscin, the glycosidic form from which it is obtained on hydrolysis.

There are about 15 species of Dioscorea genus known to contain diosgenin. Commercially important species are the following: Disogenin is also sourced from other species such as Trigonella foenum graecum (Leguminosae), sisal (Agave sisalona –Agavaceae) and Solanum species (S.laciniatum, S.marginatum).

A number of species of Dioscorea are cultivated largely for their large starchy tubers, commonly called yams, which are an important food crop in many parts of the world. Apart from several important edible species, a number of species accumulate quite high levels of saponins in their tubers which make them bitter and toxic, but…

Costa Rica is at present the principal source of the drug. World trade in the root has come down of late due to introduction of highly effective synthetic anti-amoebic drugs. Continuous use of such drugs caused resistant strains of the protozoan, resulting in the revival of demand for ipecac. At present there is a worldwide…

Ipecac was used as an insect repellant and amoebicide by South American Indians. It was introduced in Europe in the late 16th century and became well known in medicine. Ipecac is used as an expectorant and emetic and in the treatment of amoebic dysentery. Both emetine and synthetic drug 2,3-dehydro emetine are anti-amoebic and act…

Ipecacuanha or ipecac consists of the dried rhizomes and roots of Cephaelis ipecacuanha (Bortero) or Cephaelis acuminata (Karsten) (Rubiaceae). Commercial Importance Ipecac in the form of syrup is used in the treatment of drug overdose and poisoning for its emetic effect. Vomiting induced by emetine, a principal alkaloid of ipecac, is used as model to study the therapeutic effect…

Demand for cinchona and quinine products is increasing as they are extensively used not only as antimalarials, but huge quantities are also used in the manufacture of tonic drinks, and soft beverages. Salts of quinine are also added to hair oils, sunburn lotions, moth repellants, insecticides, vulcanization accelerators in rubber industry, polarized lenses and as…

A considerable number of alkaloids have been characterized in the bark, four of which account for 30% to 60% of the alklaoidal content. These are quinine, quinidine, cinchonidine and cinchonine. These are quinoline-containing structures representing two pairs of diastereoisomers. Quinine is usually the major component (one-half to two-thirds of total alkaloids), but the proportions of…