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Drosera Species (Sundew): In Vitro Culture and the Production of Plumbagin and Other Secondary Metabolites

1999; Springer Nature; Linguagem: Inglês

10.1007/978-3-662-08614-8_7

2512-3696

Jozef Šamaj, Alžbeta Blehová, Miroslav Repčák, Miroslav Ovečka, M. Bobák,

Medicinal Plants and Neuroprotection

Carnivorous plants have attracted considerable attention from many biologists for several hundred years, not only because of their special nutritional requirements and ecological adaptations, but also because of their value as medicinal herbs (Lecoufle 1990). Among them, Charles Darwin studied insectivorous plants in detail and used them in his evolutionary studies (Darwin 1875). The genus Drosera, which consists of about 125 species (Culham and Gornall 1994), represents a really good example of plant evolution and functional adaptation. Importantly, extracts from numerous species of Drosera have been traditionally used for various medicinal purposes, especially as efficient agents against respiratory diseases (Table 1). These therapeutic effects are thought to correlate with the content of secondary metabolites, namely naphthoquinones which are synthesized and accumulated in various Drosera species (Zenk et al. 1969; Culham and Gornall 1994). Among naphthoquinones, the most intensively studied has been plumbagin, because of its broad medicinal and other effects (see Finnie and van Staden 1993). However, many Drosera species also contain the second of the two most abundant naphthoquinones of Droseraceae, called 7-methyljuglone. Besides this, Drosera plants synthesize several minor, but unique, naphthoquinones as well as a broad spectrum of flavonoids with practical or potential medicinal use. Plumbagin production in vivo and in vitro has been well described, especially for the two South-African species D. capensis and D. natalensis, by Crouch et al. (1990). Therefore, in this chapter attention is focused on new data on the production of 7-methyljuglone, plumbagin and minor naphthoquinones as well as flavonoids in some new Drosera species, e.g. D. spathulata and D. rotundifolia.