2.2. Culture, extraction, and isolation
The culture filtrate from Plectophomella sp. was exhaustively extracted with ethyl ethanoate and concentrated in vacuo to afford 7.0 g of extract which was separated into six fractions by column chromatography on silica gel, using gradients of dichloromethane/ethyl acetate (85:15, 50:50,0:100). (-)-Mycorrhizin A (9.5 mg) was isolated from fraction 1 by further chromatography on silica gel 60 (Merck) and in this case using dichloromethane-MeOH (1%-10% MeOH) as eluent.