Aspermeroterpenes A–C: Three Meroterpenoids from the Marine-Derived Fungus <i>Aspergillus terreus</i> GZU-31-1

Abstract

Aspermeroterpene A (<b>1</b>) with an unprecedented and highly congested 5/3/6/6/6/5 hexacyclic skeleton, together with two precursors aspermeroterpenes B (<b>2</b>) and C (<b>3</b>), were isolated from the marine-derived fungus <i>Aspergillus terreus</i> GZU-31-1. Their structures were elucidated by quantum chemical calculations, X-ray diffraction, and spectroscopic methods. The biogenetic pathway for <b>1</b>-<b>3</b> is proposed. Aspermeroterpenes A-C (<b>1</b>-<b>3</b>) showed significant inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells compared to positive control.