Metabolites with Insecticidal Activity from Aspergillus fumigatus JRJ111048 Isolated from Mangrove Plant Acrostichum specioum Endemic to Hainan Island

Abstract

Fungi residing in mangroves are considered to be a bank of novel bioactive natural products. In the screening for bioactive metabolites from mangrove-derived fungi, the ethyl acetate extract of the fermentation broth of <i>Aspergillus fumigatus</i> JRJ111048, a fungus isolated from the leaves of the mangrove plant <i>Acrostichum specioum</i> endemic to Hainan island, was found to possess insecticidal activity against <i>Spodoptera litura</i>. Bioactivity-guided isolation lead to the discovery of seven metabolites <b>1</b>-<b>7</b>, including one new anhydride derivative aspergide (<b>1</b>), one new lipid amide 11-methyl-11-hydroxyldodecanoic acid amide (<b>2</b>), and five known compounds; α-ethyl glucoside (<b>3</b>), spiculisporic acid B (<b>4</b>), spiculisporic acid C (<b>5</b>), spiculisporic acid (<b>6</b>), and secospiculisporic acid B (<b>7</b>). Their structures were established by NMR spectroscopic and MS analyses, and by comparison of previously reported data. Insecticidal activity against <i>S. litura</i> and antifungal activity of these compounds were investigated. As a result, the new compound <b>1</b> showed potent insecticidal activity against newly hatched larvae of <i>S. litura</i>, and compound <b>4</b> displayed weak antifungal activity against <i>Candida albicans</i>.