title: Friedelane triterpenes from Celastrus vulcanicola as photosynthetic inhibitors.
abstract: Five friedelane triterpenoids, epifriedelinol (1), friedelin (2), canophyllol (3), pulpononic acid (4) and 3-oxo-29-hydroxyfriedelane (5), were isolated from Celastrus vulcanicola (Celastraceae), and were identified by spectroscopic methods, comparison with authentic samples and reported data. In the search for potential herbicides, compounds 1-5 were evaluated for their photosynthetic inhibitory activity. Compound 1 acts as an energy transfer inhibitor, interacting and enhancing the light-activated Mg(2+)-ATPase, while 3 behaves as a Hill reaction inhibitor. The in vivo assays indicated that 1 and 3 act as selective postemergence herbicides at 100 μM by reducing biomass production in the weed Physalis ixocarpa. Moreover, results from Chl a fluorescence transients in leaves of Lolium perenne and P. ixocarpa suggest that both compounds affect photosynthesis efficiency of the chloroplasts as a response to a process of detoxification and repair. Thus, 1 and 3 reduce biomass by more complex mechanisms than only the damaging of the photosynthetic apparatus.
authors.affiliation: Instituto Universitario de Bio-Orgánica "Antonio González", Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez 2, 38206 La Laguna, Tenerife, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Torres-Romero
authors.forename: Beatriz
authors.initials: B
authors.lastname: King-Díaz
authors.forename: Reto J
authors.initials: RJ
authors.lastname: Strasser
authors.forename: Ignacio A
authors.initials: IA
authors.lastname: Jiménez
authors.forename: Blas
authors.initials: B
authors.lastname: Lotina-Hennsen
authors.forename: Isabel L
authors.initials: IL
authors.lastname: Bazzocchi
mesh_terms: D031247:Celastrus / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry / Q000494:pharmacology*; D008129:Lolium / Q000187:drug effects* / Q000378:metabolism; D015394:Molecular Structure; D010788:Photosynthesis / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D057685:Plant Weeds / Q000187:drug effects* / Q000378:metabolism; D014315:Triterpenes / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D006540:Herbicides; D010936:Plant Extracts; D014315:Triterpenes; C421805:friedelane