Isolation and Synthesis of Misszrtine A: A Novel Indole Alkaloid From Marine Sponge-Associated Aspergillus sp. SCSIO XWS03F03

Abstract

A novel indole alkaloid, misszrtine A (<b>1</b>), was isolated from marine sponge-derived fungus <i>Aspergillus</i> sp. SCSIO XWS03F03. The planar structure of <b>1</b> was assigned by analysis of spectroscopic data, the absolute configuration of which was unambiguously determined by total synthesis. Compound <b>1</b> represents the first example of <i>N</i>-isopentenyl tryptophan methyl ester with a phenylpropanoic amide arm, which exhibited a potent antagonistic activity on HL60 (IC₅₀ = 3.1 μM) and LNCaP (IC₅₀ = 4.9 μM) cell lines. Bioactivity evaluation reveals that functional group on indole nitrogen of <b>1</b> has a great effect on its cytotoxity, which provides a mean to probe the structure-activity relationships of <b>1</b>.