Eremophilane Sesquiterpenes and Diphenyl Thioethers from the Soil Fungus Penicillium copticola PSU-RSPG138

Abstract

Four new compounds including two eremophilane sesquiterpenes, penicilleremophilanes A (<b>1</b>) and B (<b>2</b>), as well as two sulfur-containing biphenols, penicillithiophenols A (<b>3</b>) and B (<b>4</b>), were isolated from the soil fungus Penicillium copticola PSU-RSPG138 together with 16 known compounds. Their structures were elucidated by spectroscopic methods. Known sporogen AO-1 exhibited significant antimalarial activity against Plasmodium falciparum with an IC₅₀ value of 1.53 μM and cytotoxic activity to noncancerous (Vero) cell lines with an IC₅₀ value of 4.23 μM. Although compound <b>1</b> was approximately half as active against P. falciparum with the IC₅₀ value of 3.45 μM, it showed much weaker cytotoxic activity