Fumi Quinoline S(1), a new quinazoline-containing alkaloid and the known Fumi Quinazoline and L of the same structural class were isolated from the solid-substrate culture of an Aspergillus sp. fungus collected from marine-submerged wood. In addition,isochaetominines A-C and 14 ,new alkaloids possessing an unusual amino acid-based tetracyclic core framework related to the Fumiquinazoline,were isolated from the same fungus strain. The structures of these compounds were determined by combined spectroscopic methods,and absolute configuration were assigned by No,Ro,and advanced Marfey's analyses along with biogenetic considerations. The new compounds exhibited weak inhibition against Na K atpase