Abstract
Ten gibberellins (GAs) have been identified by Kovats retention indices and full mass spectra from GC-MS analysis of purified extracts of sporophytes of the tree-fern, Cyathea australis. These include the known GA(1), GA(4), GA(9), GA(15), GA(24), GA(35), and GA(58) and three new GAs, 12beta-hydroxyGA(9) (GA(69)), 12alpha-hydroxyGA(9) (GA(70)) and 12beta-hydroxyGA(4) (GA(71)). The structure of GA(71) was established by the preparation and characterization of its methyl ester (as a metabolite of GA(4) methyl ester in a culture of prothallia of Lygodium japonicum).