Heterocycles and a Sorbicillinoid from the Coral-Derived Fungus .

A detailed chemical study of the culture of a coral-derived fungus resulted in the isolation and identification of four new aromatic heterocycles chrysoquinazolinones A-B (-) and chrysobenzothiazoles A-B (-), along with a new sorbicillinoid 4-carboxylsorbicillin (). Chrysoquinazolinones A-B (-) combine a quinazolinone fragment with a bicyclo[2.2.2]octane or a pyrrolidone moiety, respectively, demonstrating the unexpected structures of marine natural products. Chrysobenzothiazoles A-B (-) possess a benzothiazole system and are the second isolation of this class of skeleton compounds from marine organisms. The existence of the pair of enantiomers (±) was deduced by chiral HPLC analysis. Their structures and absolute configurations were elucidated by detailed spectroscopic analysis, comparison with the literature data, single-crystal X-ray crystallographic analysis and TDDFT-ECD calculations. Compound exhibited moderate cytotoxicity against K562 and NCI-H446 cell lines, with IC values of 15.00 μM and 16.87 μM, respectively.