Phenylphenalenone-related compounds: chemotaxonomic markers of the haemodoraceae from Xiphidium caeruleum.

Phytochemical analysis of Xiphidium caeruleum, a neotropical member of the family Haemodoraceae, resulted in the isolation and identification of a variety of phenylphenalenone-related compounds. The structures of four new phenylbenzoisochromenones (3, 6, 7, 10), a new phenylbenzoisoquinolinone (4), and two new oxabenzochrysenones (11, 12) were elucidated using MS and NMR spectroscopic techniques. In addition, five new glucosides (14-18) were identified, among them four allophanyl glucosides (15-18), representing a novel type of 6'-substituted glucosidic natural product. On the basis of the common occurrence of these 12 new and four known structures (2, 5, 9, 13), hypothetical biosynthetic relationships are discussed. The natural product distribution of other genera of the Haemodoraceae is used as the basis to elaborate biogeographic characteristics of this plant family.