Two New Oxysporone Derivatives from the Fermentation Broth of the Endophytic Plant Fungus <em>Pestalotiopsis karstenii</em> Isolated from Stems of <em>Camellia sasanqua</em>

Abstract

Two new oxysporone derivatives, pestalrone <strong>A</strong> (<strong>1</strong>) and pestalrone <strong>B</strong> (<strong>2</strong>), along with two known structurally related compounds <strong>3</strong>,<strong>4</strong>, were from the fermentation broth of the endophytic plant fungus <em>Pestalotiopsis karstenii</em> isolated from stems of <em>Camellia sasanqua</em>. Their structures and relative configurations were elucidated by extensive spectroscopic analysis and comparison of chemical shifts with related known compounds. Compound <strong>2</strong> exhibited significant activities agains HeLa, HepG2 and U-251 with IC₅₀ values of 12.6, 31.7 and 5.4 µg/mL, respectively.

Keywords

• &lt;em&gt;Pestalotiopsis karstenii&lt;/em&gt;
• secondary metabolites
• pestalrone A
• pestalrone B