Novel skeleton sesquiterpenoids isolated from guava leaves

<p>A chemical investigation of the plant <i>Psidium guajava</i> L., collected in Guangdong province, afforded two novel skeleton sesquiterpenoids <b>1</b> and <b>2</b>. Compound <b>2</b> also known as isocaryolan-9-one was a new natural product. The structure of the novel compound <b>1</b> was determined as guavacid A by various spectroscopic methods. A possible biosynthetic pathway for <b>1</b> and <b>2</b> was proposed.</p>