Ageratina adenophora (Spreng.) K. & R.: In Vitro Culture and the Production of Secondary Metabolites

Abstract

The family Asteraceae comprises some 20,000 species and is the second largest family of higher plants (Heywood et al. 1977). Considering the size of this family it is interesting to note that relatively few species are commercially exploited as food plants, whereas a comparatively large number is known to accumulate poisonous natural products such as sesquiterpene lactones that are cytotoxic or elicit contact allergy or liver toxic pyrrolizidine alkaloids (Wagner 1977). In evolutionary terms, the Asteraceae is still a young plant family that has nevertheless successfully spread worldwide (Turner 1977). There is now increasing evidence suggesting that the accumulation of toxic natural products forms a major ecological contribution to the successful radiation of the Asteraceae as well as of other families, enabling plants to fight off herbivors or pathogenic microorganisms (Rosenthal and Janzen 1979). In search of new sources of potentially useful natural products that may become important as key structures for designing new drugs or agrochemicals, it is appropriate to focus on those species that are the most vigorous and have successfully adapted to different habitats, since they can be expected to contain an effective arsenal of interesting biologically active compounds.