Ophiosphaerellins A–I, Polyketide-Derived Compounds from the Endolichenic Fungus Ophiosphaerella korrae

High Resolution Image Download MS PowerPoint Slide Ophiosphaerellins A–I ( 1 – 9 ), the first example of bicyclo[4.1.0]heptenones, as well as their biosynthetic relatives ophiosphaerekorrins A–B ( 10 – 11 ) were isolated from the endolichenic fungus Ophiosphaerella korrae . Biosynthetically, they were derived from the polyketide pathway, and their absolute configurations were determined on the basis of the combination analysis of spectral data, circular dichroism calculations, and single-crystal X-ray diffraction measurement. Preliminary test with thin-layer chromatography bioautography found that this type of compounds showed moderate acetylcholinesterase (AChE) inhibitory effects.