title: Biomimetic conversion of (-)-fusoxypyridone and (-)-oxysporidinone to (-)-sambutoxin: further evidence for the structure of the tricyclic pyridone alkaloid, (-)-fusoxypyridone.
abstract: Biomimetic-type reactions of the tricyclic pyridone alkaloid, (-)-fusoxypyridone [(-)-4,6'-anhydrooxysporidinone] (1), recently encountered in an endophytic strain of Fusarium oxysporum, and (-)-oxysporidinone (2) afforded (-)-sambutoxin (3) and an analogue of 1, identified as (-)-1'(6')-dehydro-4,6'-anhydrooxysporidinone (4), thus confirming the structure previously proposed for 1 and suggesting that 1-3 bear the same relative stereochemistry. Oxidation of 4 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) yielded a hitherto unknown sambutoxin analogue, (-)-4,2'-anhydrosambutoxin (5).
authors.affiliation: Southwest Center for Natural Products Research and Commercialization, Office of Arid Lands Studies, School of Natural Resources and The Environment, College of Agriculture and Life Sciences, The University of Arizona, 250 E. Valencia Road, Tucson, AZ 85706-6800, USA.
authors.forename: E M Kithsiri
authors.initials: EM
authors.lastname: Wijeratne
authors.forename: A A Leslie
authors.initials: AA
authors.lastname: Gunatilaka
mesh_terms: D000470:Alkaloids / Q000737:chemistry*; D032701:Biomimetics; D005670:Fusarium / Q000737:chemistry; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009183:Mycotoxins / Q000737:chemistry*; D010084:Oxidation-Reduction; D011728:Pyridones / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D006575:Heterocyclic Compounds, 3-Ring; D009183:Mycotoxins; D011728:Pyridones; C104552:oxysporidinone; C091237:sambutoxin