Anti-Inflammatory Sesquiterpenes from Fruiting Bodies of <i>Schizophyllum commune</i>

Abstract

<i>Schizophyllum commune</i>, a fleshy fungus, is an important medicinal and food-homologous mushroom in China. In this work, eight undescribed sesquiterpenes schizomycins A-H (<b>1</b>-<b>8</b>) and one new meroterpenoid schizomycin I (<b>9</b>) together with three known analogues (<b>10</b>-<b>12</b>) were isolated from fruiting bodies of <i>S. commune</i>. Their planar structures were established by extensive spectroscopic and mass spectrometric data. The absolute configurations of compounds <b>1</b>, <b>2</b>, and <b>4</b> were determined by single crystal X-ray diffraction, and compounds <b>3</b> and <b>5</b>-<b>9</b> were confirmed by electronic circular dichroism calculations. Anti-inflammatory activities of all isolated compounds were evaluated for their inhibitory effects on IL-6 and IL-1β production in RAW 264.7 cells. Among them, compound <b>7</b> exhibited significant IL-6 inhibitory activity with an IC₅₀ value of 3.6 μM. The results of molecular docking showed that compound <b>7</b> interacts with amino acid residues (Gly117, Lys118, Asp120, Thr166, and Try168) of the IL-6 receptor protein through hydrogen bonding.