Dihydroisocoumarins from the Mangrove-Derived Fungus Penicillium citrinum

Abstract

Three new dihydroisocoumarin penicimarins G-I (<b>1</b>-<b>3</b>), together with one known dihydroisocoumarin (<b>4</b>) and three known meroterpenoids (<b>5</b>-<b>7</b>), were obtained from a fungus <i>Penicillium citrinum</i> isolated from the mangrove <i>Bruguiera sexangula</i> var. <i>rhynchopetala</i> collected in the South China Sea. Their structures were elucidated by the detailed analysis of spectroscopic data. The absolute configuration of <b>1</b> was determined by the X-ray diffraction analysis using Cu Kα radiation. The absolute configurations of <b>2</b> and <b>3</b> were determined by comparison of their circular dichroism (CD) spectra with the literature. All compounds were evaluated for their antibacterial activities and cytotoxic activities.