Scopolia spp.

2015

Scopolia comprises a number of species which are a rich source of tropane alkaloids. In the literature the following species and synonyms have been mentioned:

Scopolia acutangula Wu et Chen

Scopolia atropoides

Scopolia carniolica Jacq. [Asia, Eastern Europe]

Scopolia hladnikiana

Scopolia japonica Maxim [Japan]

Scopolia lurida

Scopolia parviflora Nakai [Korea]

Scopolia physaloides Dun

Scopolia sinensis [China]

Scopolia stramonifolia [Central Himalaya]

Scopolia tangutica [West China]

Synonyms are:

Scopolia atropoides = Scopolia hladnikiana = Scopolia carniolica

Scopolia stramonifolia = Scopolia lurida = Anisodus luridus = Anisodus stramonifolius

Scopolia physaloides = Physalis virginiana

Scopolia acutangula = Anisodus acutangulus

Scopolia tangutica = Anisodus tanguticus

Scopolia parviflora = Scopolia japonica var. parviflora

Zheng () gives a fourth species of Anisodus: A. mairei. It is not known whether this species has been described as a Scopolia species.

Scopolia carniolica from West Asia was naturalized in Europe. As far as is known, in the last century Scopolia carniolica was cultivated to some extent in the Netherlands and in Lithuania. There was Uttle demand for cultivated plants, however, since plant material could easily be supplied by collecting plants in nature. Both the leaves (Herba Scopoliae) and the roots (Radix Scopoliae) were used.

Scopolia parviflora (Scopolia japonica var. parviflora) is very similar to Scopolia japonica, not only morphologically but also with respect to alkaloid composition and pharmacological activity. From both plants, rhizome extracts are used as antispasmodics. The rhizome of Scopolia parviflora contains 0.34% dry wt. total alkaloid ().

The family Solanaceae consists of about 68 genera. From 21 of these, over 30 different tropane alkaloids have been described. In Scopolia, depending on the organ examined, hyoscyamine or scopolamine can be found (). Roots of intact plants contain considerable amounts of cuscohygrine, pseudotropine, and tig-loidine. Other nontropane alkaloid components reported are pyridin alkaloids, rutin, kaempferol-3-rhamnoglucosid, astragalin, chlorogenic acid, and aesculetin (). The coumarin scopoletin and its monoglucoside, scopoline, are characteristic for Solanaceae. In the leaves of adult plants of Scopolia carniolica we measured 0.19% dry wt. hyoscyamine and 0.13% scopolamine.

The tropane alkaloids scopolamine and hyoscyamine are used in medicine for their parasympatholytic and anticholinergic activity. The chemical synthesis of tropane alkaloids has been described (), but for economic reasons these alkaloids are still extracted from plant material. The solanaceous plants containing tropane alkaloids, especially the plants belonging to the genera Atropa, Datura, Duboisia, Hyoscyamus, and Scopolia, are known for their relative high scopolamine and hyoscyamine content (0.04-0.6% dry wt., on a dry weight basis).

Cell cultures of Scopolia show all the benefits of tissue culture of solanaceous plants: cell cultures can be easily handled and regeneration of plants has been described. For the production of tropane alkaloids with root or cell cultures, the concentrations of hyoscyamine and scopolamine are not of economic value. Cell cultures have to compete with high producing plants like H. muticus with over 4% dry wt. scopolamine (). However, if high cellular concentrations of tropane alkaloids can be reached, the controlled production of biomass has clear advantages. To reach such high levels, selection of high producing cell lines and genetic manipulation are inevitable. Some basic level of alkaloids in cells is favorable, and Scopolia meets all the requirements. Perhaps more promising are the results of Cheng et al. () and Zheng () with bioconversion of hyoscyamine to scopolamine. Apparently, in Scopolia cells all biosynthetic systems are active, and therefore these cells are very suitable for studies which focus on the key problem in undifferentiated tissues: the esterification of tropine and tropic acid to hyoscyamine.

 

Selections from the book: “Medicinal and Aromatic Plants IV”, 1993.