Simplexins P–S, Eunicellin-Based Diterpenes from the Soft Coral <em>Klyxum simplex</em>

Abstract

Four new eunicellin-based diterpenes, simplexins P–S (<strong>1</strong>–<strong>4</strong>), and the known compound simplexin A (<strong>5</strong>), have been isolated from the soft coral<em> Klyxum simplex</em>. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis, particularly 1D and 2D NMR experiments. Compounds <strong>1 </strong>and<strong> 3</strong>–<strong>5</strong> were shown to exhibit cytotoxicity against a limited panel of cancer cell lines, <strong>3</strong> being the most cytotoxic.

Keywords

• soft coral
• eunicellin-based diterpenes
• cytotoxicity
• &lt;em&gt;Klyxum simplex&lt;/em&gt;