Family Dioscoreaceae R Brown 1810 nom conserv the Yam family

Physical description: The family Dioscoreaceae consists of approximately 6 genera and 650 species of tropical climbers growing from rhizomes or tubers. It is known to produce raphides of calcium oxalate, steroidal saponins, some alkaloids, chelidonic acid and tannins. The family is dominated by the large genus Dioscorea consisting of 600 species of plants. The leaves are simple and alternate. The blade is often cordate and the petiole is twisted, long and thin. The inflorescences are racemes or panicles. The flowers are small, perfect or unisexual, regular, epigynous, and trimerous. The perianth consists of 6 tepals and the andrecium comprises of 6 stamens in 2 cycles. The anthers are tetrasporangiate, dithecal and open by longitudinal slits. The gynecium consists of 3 carpels united to form a compound, inferior, 3-locular ovary with each locule containing 2 to a couple of anatropous, bitegmic and crassinucellar ovules, attached to axile placentas. The styles are free. The fruits are capsular, dehiscing and characteristically 3-winged. The seeds are winged and with copious endosperm.

Pharmaceutical interest: Dioscorea alata L., Dioscorea oppositifolia Thunb. (Dioscorea batatas Decne) and Dioscorea esculenta (Lour.) Burk. have been cultivated since ancient times for their edible starchy tubers (yams). These tubers are sometimes voluminous and are very rich in starch, containing a steroidal saponins that provide after hydrolysis diosgenin, a raw material

Taccalonolide M

Spirostanol saponins

OHi OH

Taccalonolide M

Spirostanol saponins for the manufacture of steroidal hormones. The consumption of the raw tuber of Dioscorea may often result in painful mouth burning, gastrointestinal upset and convulsions, owing to an alkaloid termed dioscorine, derived from nicotinic acid. This alkaloid is poisonous and the tubers must be thoroughly washed in a long and tedious process, for the tuber to be edible when cooked. In Southeast Asia, Dioscorea bulbifera L., Dioscorea hispida Dennst., Dioscorea japonica Thunb., Dioscorea oppositifolia Thunb., Dioscorea tokoro Mak., Dioscorea quinquelobaThunb., Dioscorea alata L., Dioscorea esculenta Burk. and Dioscorea filiformis Bl. are of medicinal values. The tubers are often used to maturate boils, heal sores, counteract snake poisoning and putrefaction, assuage rheumatic pains, treat leprosy, invigorate health and to treat kidney diseases.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

Get My Free Ebook


Post a comment