New Prenylated Indole Homodimeric and Pteridine Alkaloids from the Marine-Derived Fungus Aspergillus austroafricanus Y32-2

Abstract

Chemical investigation of secondary metabolites from the marine-derived fungus <i>Aspergillus austroafricanus</i> Y32-2 resulted in the isolation of two new prenylated indole alkaloid homodimers, di-6-hydroxydeoxybrevianamide E (<b>1</b>) and dinotoamide J (<b>2</b>), one new pteridine alkaloid asperpteridinate A (<b>3</b>), with eleven known compounds (<b>4</b>-<b>14</b>). Their structures were elucidated by various spectroscopic methods including HRESIMS and NMR, while their absolute configurations were determined by ECD calculations. Each compound was evaluated for pro-angiogenic, anti-inflammatory effects in zebrafish models and cytotoxicity for HepG2 human liver carcinoma cells. As a result, compounds <b>2</b>, <b>4</b>, <b>5</b>, <b>7</b>, <b>10</b> exhibited pro-angiogenic activity in a PTK787-induced vascular injury zebrafish model in a dose-dependent manner, compounds <b>7</b>, <b>8</b>, <b>10</b>, <b>11</b> displayed anti-inflammatory activity in a CuSO₄-induced zebrafish inflammation model, and compound <b>6</b> showed significant cytotoxicity against HepG2 cells with an IC₅₀ value of 30 µg/mL.