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

Abstract

Three new diphenyl ether derivatives-phomaethers A-C (<b>1</b>-<b>3</b>) and five known compounds-including a diphenyl ether analog, 2,3'-dihydroxy-4-methoxy-5',6-dimethyl diphenyl ether (<b>4</b>); and four isocoumarin derivatives, diaportinol (<b>5</b>), desmethyldiaportinol (<b>6</b>), citreoisocoumarinol (<b>7</b>), and citreoisocoumarin (<b>8</b>)-were isolated from a gorgonian-derived fungus <i>Phoma</i> sp. (TA07-1). Their structures were elucidated by extensive spectroscopic investigation. The absolute configurations of <b>1</b> and <b>2</b> were determined by acid hydrolysis reactions. It was the first report to discover the diphenyl glycoside derivatives from coral-derived fungi. Compounds <b>1</b>, <b>3</b>, and <b>4</b> 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.