Pseudodeflectusin, a novel isochroman derivative from Aspergillus pseudodeflectus a parasite of the sea weed, Sargassum fusiform, as a selective human cancer cytotoxin

Abstract A new isochroman derivative named pseudodeflectusin was isolated from a culture broth of Aspergillus pseudodeflectus . The structure was determined by spectroscopic means as 9-hydroxy-7-methyl-2-(methylethylidine)-furano[3,2- H ]isochroman-3-one. This compound exhibited cytotoxicity for several human cancer cell lines from the stomach (NUGC-3), cervix (HeLa-S3), and peripheral blood (HL-60), but did not affect those from the lung (A549) or colon (DLD-1). The LD 50 value of this compound for HL-60 cells was 39 μM.