Dioscorea hispida

In Dioscorea hispida, Trigollenine is incorporated into the isoquinuclidine moiety of the alkaloid Dioscorine (208), as proved by a feeding experiment with [TOer/ y/- " C,2- H, H]trigollenine (88P3793). These results are consistent with the hypothesis for the biosynthesis of Dioscorine (208), Dumetorine and Dihydrodioscorine, which is presented in Scheme 68. 

A brief reduction in physical activity of mice after dosing with an extract of the tropical yam, Dioscorea hispida, was attributed to the alkaloid 278 [615]. 

Dioscorine, C13H19O2N (188, 248), has been isolated from the tubers ( gadoeng ) of Dioscorea hirsuta Blume (241) and from the same organ ( nami ) of Dioscorea hispida Dennst. which are indigenous to Batavia and the Tagalog provinces of the Philippines. Gadoeng and nami are used by the natives as a foodstuff after removal of the poisonous principle. 

Piperidine Alkaloids.—The hypothesis that dioscorine (112) was derived from six acetate units has been tested by administration of sodium [l- " C]acetate to Dioscorea hispida. Degradation of the dioscorine isolated showed, significantly, that of the carbons of the isoquinuclidine ring only C-5 was heavily labelled (30% of total). The remaining activity was located equally at C-10 and C-12. Thus dioscorine is built of only four acetate units, the remaining carbons of the skeleton being derived probably from lysine via a piperidine moiety such as A -piperideine (Scheme 10). 

Dioscorea cirrhosa L. D. hispida Dennst. D. japonica Thunb. Shu Liang (Dyeing yam) (tuber) Tannins, mucus 33 Hemostatic, increases platelet aggregation, increases uterine contraction. 

Rhamnus davurica Pall., R. parvifolia Bunge., R. davurica Pall. var. nipponica Makino Dioscorea cirrhosa, D. japonica Thunb., D. hispida Dennst. 

D. triquetrum, Dioscorea bulbifera, D. cirrhosa, D. hispida, D. japonica, Dodonaea viscosa Geranium dahuricum, G. eriostemon, G. sibiricum, G. wlassowianum, G. wilfordi, Jasminum mesnyi, J. nudiflorum, Hippophae rhamnoides, Lappa communis, L. edulis, L major, L. minor, Lonicera acuminata,... 

Alkaloids are known in a few members of the family. Tests on 45 samples which included 37 species resulted in three positives in plants known to be alkaloidal (Dioscorea dumetorum, D. hispida, D. alaia) and in two of 13 other unidentified Dioscorea species. The remainder were negative Dioscorea abyssinica, D. alata, D. batatas, D. bucha-nanii, D. bulbifera, D. composita, D. cotinifolia, D. doryophora, D. dregeana, D. esculenla, D. hemicrypta, D. hirtiflora, D. mexicana, D. pentaphylla, D. quartiniana, D. retusa, D. sylvatica, D. trifida, Tamus edulis. 

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