STRUCTURES AND ABSOLUTE-CONFIGURATIONS OF ANTIBIOTICS OF THE OLIGOSPORON GROUP FROM THE NEMATODE-TRAPPING FUNGUS ARTHROBOTRYS OLIGOSPORA

Spectroscopic data define the structures of three new antibiotics, 4', 5'-dihydro-oligosporon (4), hydroxyoligosporon (5) and 10',11'-epoxyol igosporon (6) from the nematode-trapping fungus Arthrobotrys oligospor a, and confirm the structures of the recently reported antibiotics oli gosporon (1) and oligosporol B (3). The absolute configuration of the substituted 7-oxabicyclo[4.1.0]hept-3-ene nucleus of these metabolites is determined by circular dichroic spectroscopy. Oligosporon (1) and its dihydro-derivative (4) represent the second and most complex struc tural type of nematocidal metabolite to be characterised from cultures of nematophagous fungi.