Inhibitory Effects of Maleimide Derivatives from the Mycelia of the Fungus Antrodia cinnamomea BCRC 36799 on Nitric Oxide Production in Lipopolysaccharide (LPS)‐Activated RAW264.7 Macrophages

Abstract

<jats:title>Abstract</jats:title><jats:p>Four new maleimide derivatives, antrocinnamomins E–H (<jats:bold>1</jats:bold>–<jats:bold>4</jats:bold>, resp.), together with (3<jats:italic>S</jats:italic>,4<jats:italic>R</jats:italic>)‐1‐hydroxy‐3‐(4‐hydroxyphenyl)‐4‐(2‐methylpropyl)pyrrolidine‐2,5‐dione (<jats:bold>5</jats:bold>) and ergosterol were isolated from the mycelia of <jats:italic>Antrodia cinnamomea</jats:italic> BCRC 36799. The structures were elucidated by 1D‐ and 2D‐NMR spectroscopy, and mass spectrometry. Compounds <jats:bold>1</jats:bold>–<jats:bold>5</jats:bold> were evaluated for their inhibitory effects on nitric oxide (NO) production by macrophages. Compounds <jats:bold>2</jats:bold> and <jats:bold>4</jats:bold> showed stronger inhibition of NO production than the positive control quercetin.