Genuine and Sequestered Natural Products from the Genus Orobanche (Orobanchaceae, Lamiales)

The present review gives an overview about natural products from the holoparasitic genus (Orobanchaceae). We cover both genuine natural products as well as compounds sequestered by taxa from their host plants. However, the distinction between these two categories is not always easy. In cases where the respective authors had not indicated the opposite, all compounds detected in taxa were regarded as genuine natural products. From the about 200 species of s.l. (i.e., including ) known worldwide, only 26 species have so far been investigated phytochemically (22 and four species), from 17 and three species defined natural products (and not only natural product classes) have been reported. For two species of and one of dedicated studies have been performed to analyze the phenomenon of natural product sequestration by parasitic plants from their host plants. In total, 70 presumably genuine natural products and 19 sequestered natural products have been described from s.l.; these form the basis of 140 chemosystematic records (natural product reports per taxon). Bioactivities described for s.l. extracts and natural products isolated from species include in addition to antioxidative and anti-inflammatory effects, e.g., analgesic, antifungal and antibacterial activities, inhibition of amyloid β aggregation, memory enhancing effects as well as anti-hypertensive effects, inhibition of blood platelet aggregation, and diuretic effects. Moreover, muscle relaxant and anti-spasmodic effects as well as anti-photoaging effects have been described.