Digitalis species

Types of Cardiac Glycoside. Three groups of plants produce cardenolides the Digitalis species, growing in temperate climates the Strophanthus species, of tropical provenance and Scilla (sea onion or squill), a Mediterranean plant. 

Many plants containing cardioactive glycosides are widely grown as ornamentals and must be considered toxic and treated with due care and respect. These include Digitalis species, Convallaria majalis, Helleborus species, and oleander (Nerium oleander, Apocynaceae). 

Botanicals Atropa belladonna, Digitalis species, Colchicum, Rauwolfia serpentina, pyrrolizidine-containing plants (see separate monograph on pyrrolizidines)... 

Isol. by mild acid hydrolysis from the glycosides lanatoside A, B and C (from Digitalis species), Erysimoside (from Erysimum perofskianum) and from the glycosides of Isoplexis isabelliana and from Isoplexis canariensis. 

Matysik and Jusiak (77) used stepwise gradient development for separation of Chelidonium alkaloids in waste industrial fraction. Binary (toluene, methanol) and ternary (toluene, ethyl acetate, methanol) mobile phases were used and a six-step program was performed. Eight-step stepwise gradient was also used for separation of the glycosides from the Digitalis species (78). 

The cardiac glycosides are mainly obtained from plants e.g. digitalis, stropanthus and squill species and also present in certain other plants and animals. In 1776, William Withering, a Birmingham... 

As part of our investigations (1,2) of the psychotropic Mexican labiate. Salvia divinorum Epling Jativa-M., we report the presence of loliolide (1), previously isolated from Lolium perenne (3), Gramineae, Digitalis purpurea L. (4), Scrophulariaceae, and several other species (5). The compound has recently been described to be a potent ant-repellent (8). 

Many other species of Digitalis, e.g. D. dubia, D. ferruginea, D. grandiflora, D. lutea, D. mertonensis, D. nervosa, D. subalpina, and D. thaspi contain cardioactive glycosides in their leaves, and some have been evaluated and cultivated for drug use. 

The positive benefits of extracts of two species of Digitalis purpurea (foxglove and lanata) were recognized long before the active constituents were isolated and structurally characterized. The cardiac glycosides, which include digoxin, digitoxin, and deslanoside, exert a powerful and selective positive inotropic action on the cardiac muscle (see Chapter 35). 

The distribution of cardiac glycosides in the plant varies in different species. Digitalis is obtained from the leaves and seeds strophanthus, from the seeds squill, from the bulbs Convallaria, from the flowers and ouabaio, from the wood and bark. In addition, there are saponin bodies that do not show the typical digitalis effect on the heart but which are extracted along with the glycosides, which possess the cardiac actions. 

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