Euroticins C-E, three pairs of polycyclic salicylaldehyde derivative enantiomers from a marine-derived fungus Eurotium sp. SCSIO F452

Euroticins C-E (1-3), three pairs of salicylaldehyde derivative enantiomers, were isolated from a marine-derived fungus Eurotium sp. SCSIO F452. They represent two types of salicylaldehyde derivatives bearing unprecedented highly constructed 6/6/6/6 tetracyclic structures. Their structures were established by comprehensive spectroscopic analyses, X-ray diffraction, and electronic circular dichroism calculations. Compounds (+)-1 and (-)-1 showed significant antioxidative activity and moderate cytotoxic activity.