Bioactive Diphenyl Ethers and Isocoumarin Derivatives from a Gorgonian-Derived Fungus Phoma sp. (TA07-1).

Three new diphenyl ether derivatives-phomaethers A-C ( 1 - 3 ) and five known compounds-including a diphenyl ether analog, 2,3'-dihydroxy-4-methoxy-5',6-dimethyl diphenyl ether ( 4 ); and four isocoumarin derivatives, diaportinol ( 5 ), desmethyldiaportinol ( 6 ), citreoisocoumarinol ( 7 ), and citreoisocoumarin ( 8 )-were isolated from a gorgonian-derived fungus Phoma sp. (TA07-1). Their structures were elucidated by extensive spectroscopic investigation. The absolute configurations of 1 and 2 were determined by acid hydrolysis reactions. It was the first report to discover the diphenyl glycoside derivatives from coral-derived fungi. Compounds 1 , 3 , and 4 showed selective strong antibacterial activity against five pathogenic bacteria with the minimum inhibiting concentration (MIC) values and minimum bactericidal concentration (MBC) values between 0.156 and 10.0 μM.