Studies on the synthesis of hyoscyamine in Atropa belladonna L. and Datura stramonium L

Abstract

The seasonal distr. of hyoscyamine in roots, stems and leaves of A. belladonna was investigated. The max. conc. occurred in July. From July to Nov. the high value was maintained in roots but a slight fall occurred in leaves. Minima for roots occurred in Mar. and for leaves in May. In autumn little evidence of downward translocation from leaves to roots was obtained. Exudate from stems cut near to the base contained appreciable amts. of hyoscyamine. The alkaloid was found to pass from the root-stocks of Atropa into tomato scions grafted thereon. Little or no hyoscyamine appeared in stocks of tomato from grafted scions of Atropa. Evidently, the root is the principal locus of synthesis of the alkaloid, and upward movement into the shoot system takes place under the influence of root pressure and transpiration. Solns. of various amines and amino-acids (0.25%) were injd. alone and in association with glucose (2%) into plants of A. belladonna and D. stramonium, to observe their influence on the synthesis of hyoscyamine. Injn. of putrescine, arginine, hexamine and formamol stimulated the formation of hyoscyamine to the greatest extent. Of these substances, putrescine (from arginine) appears to be a possible intermediate in the synthesis of hyoscyamine. Plants sprouted in darkness showed increased production of hyoscyamine. Under conditions of etiolation the production of intermediates (from protein and carbohydrate breakdown) for hyoscyamine synthesis is favored.