Peniandranoids A-E: Meroterpenoids with Antiviral and Immunosuppressive Activity from a <i>Penicillium</i> sp.
Chang JL, Gan YT, Peng XG, Ouyang QX, Pei J, Ruan HL.
Peniandranoids A-E (<b>1</b>-<b>5</b>), five new meroterpenoids, together with three known analogues (<b>6</b>-<b>8</b>), were isolated from the fermentation of a soil-derived fungus, <i>Penicillium</i> sp.sb62. Their structures including absolute configurations were determined by extensive spectroscopic analysis, and the absolute configurations of compounds <b>1</b> and <b>5</b> were further elucidated by single-crystal X-ray diffraction. Peniandranoids A-E belong to a rare class of andrastin-type meroterpenoids incorporating an extra polyketide unit (a C<sub>10</sub> polyketide unit for <b>1</b> and <b>2</b>, a C<sub>9</sub> polyketide unit for <b>3</b> and <b>4</b>, and a furancarboxylic acid unit for <b>5</b>). Compounds <b>1</b> and <b>6</b> exhibited favorable inhibitory activities against influenza virus A (H1N1) with EC<sub>50</sub> values of 19 and 14 μg/mL, respectively. Compounds <b>3</b>-<b>8</b> exhibited potent immunosuppressive activities against concanavalin A-induced T cell proliferation with EC<sub>50</sub> values ranging from 4.3 to 27 μM and lipopolysaccharide-induced B cell proliferation with EC<sub>50</sub> values ranging from 7.5 to 23 μM, respectively.