Anti-inflammatory polyketides from <i>Santalum album</i> derived endophytic fungus <i>Hypomontagnella</i> sp. TX-09

Four new lactones, including hypomonacid A (<b>1</b>) and hypomonone A-C (<b>4-6</b>), as well as nine known polyketide analogues (<b>2-3</b> and <b>7-13</b>) were obtained from endophytic fungus <i>Hypomontagnella</i> sp. TX-09 derived from <i>Santalum album</i>. Their planar structures were extensively established by analysing HRESIMS and NMR spectroscopic data. Stereochemistry of new compounds was determined by X-ray diffraction analysis and modified Mosher's method in combination with quantum-chemical ECD calculation. In addition, compounds <b>1</b> and <b>2</b> showed anti-inflammatory activity by inhibition of lipopolysaccharide (LPS)-induced NO production in RAW264.7 cells at 50 μmol/L without cytotoxicity. Among them, compound <b>1</b> inhibited the production of LPS-stimulated inflammation in mouse macrophage RAW264.7 cells by suppressing the expression of iNOS, TNF-α, IL-1β, and IL-6.