The KMM 4639 strain was identified asAmphichordasp. based on two molecular genetic markers: ITS and β-tubulin regions. Chemical investigation of co-culture marine-derived fungiAmphichordasp. KMM 4639 andAspergillus carneusKMM 4638 led to the identification of five new quinazolinone alkaloids felicarnezolines A–E (1–5), a new highly oxygenated chromene derivative oxirapentyn M (6) and five previously reported related compounds. Their structures were established using spectroscopic methods and by comparison with related known compounds. The isolated compounds showed low cytotoxicity against human prostate and breast cancer cells but felicarnezoline B (2) protected rat cardiomyocytes H9c2 and human neuroblastoma SH-SY5Y cells against CoCl2-induced damage.