[2] Under UV irradiation, stilbene and its derivatives undergo intramolecular cyclization to form dihydrophenanthrenes.
[4] The dimeric phenanthrenoid 8,8'-bidehydrojuncusol and the monomeric dehydrojuncusol can be isolated from Juncus acutus.
[6] Phenanthrenes have been reported in species of Dendrobium, Bulbophyllum, Eria, Maxillaria, Bletilla, Coelogyne, Cymbidium, Ephemerantha and Epidendrum.
[15] Coelogyne cristata contains coeloginanthridin (3,5,7-trihydroxy-1,2-dimethoxy-9,10-dihydrophenanthrene), a 9,10-dihydrophenanthrene derivative, and coeloginanthrin (3,5,7-trihydroxy-1,2-dimethoxyphenanthrene), the corresponding phenanthrene analogue, coelogin and coeloginin.
[16] Orchinol and loroglossol have a phytoalexin effect and reduce the growth of Cattleya aurantiaca seedlings.