D. purpurea is a common ornamental plant of England well known for its medicinal properties. Horticultural varieties grown as garden plants are low in therapeutic glycosides. For pharmaceutical purposes, cultivation is preferable to collection from wild plants because factors such as the climate, soil, age of the plant, season, storage and drying method and genetic makeup…
D. purpurea and Digitalis lanata are the two economically important sources of cardiac glycosides. Both are biennial or perennial herbs growing in semi-shady regions in the wild state. Presently the leaves are collected from cultivated plants. D. purpurea is common in UK and most of Europe and naturalized in northern and western USA and Canada. Major centres of cultivation are…
It consists of the dried leaves of the ‘purple foxglove’, Digitalis purpurea, belonging to the family Scrophulariaceae Commercial Importance Leaves of digitalis species contain medicinally important glycosides of the cardenolide group. Called cardiac glycosides, these C23 steroidal glycosides exert a slowing and strengthening effect on a failing heart. In conventional medicine, glycosides of digitalis are extensively employed…
Demand for diosgenin for pharmaceuticals is huge, equivalent to 10,000 tonnes of Dioscorea tuber per annum. Until 1970 Mexican yam was the only source of diosgenin for steroidal contraceptive manufacture. Following nationalization of the Mexican industry, prices increased drastically forcing the search for alternative sources of diosgenin and alternatives to diosgenin. Fenugreek seeds are exploited…
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…