Secondary metabolites from the <i>Colletotrichum gloeosporioides</i> A12, an endophytic fungus derived from <i>Aquilaria sinensis</i>

<p>Two new cyclohexene derivatives colletotricones A and B (<b>1</b> and <b>2</b>) and a new thiazole derivative colletotricole A (<b>5</b>), along with six known natural metabolites were isolated from the extract of <i>Colletotrichum gloeosporioides</i> A12, an endophytic fungus derived from <i>Aquilaria sinensis</i>. Among them, the colletotricones A and B possess a cyclohexenone skeleton, whereas the colletotricole A is a thiazole derivative. Their structures were fully assigned with the aid of extensive spectroscopic analysis and data from the literature. Moreover, cytotoxic activity <i>in vitro</i> of compounds <b>1</b> and <b>3–9</b> were evaluated against MCF-7, NCI-H460, HepG-2 and SF-268 tumour cell lines. The new compound <b>1</b> exhibited growth inhibitory activity against all the four tumour cell lines with IC<sub>50</sub> values ranging from 15.7 to 46.8 μM.</p>