New Polyketides From <i>Trichoderma harzianum</i> and Their Antifungal Activity

Chemical investigation of the marine-derived fungus Trichoderma harzianum ZN-4 led to the isolation and identification of seven new secondary metabolites, harzianolides K-Q (1-7). The complete structures of seven new compounds were determined by high-resolution mass spectrometry and nuclear magnetic resonance spectroscopic analyses coupled with electronic circular dichroism calculations. The seven isolates were inactive as antibacterial and antitumor agents. However, harzianolides K (1), L (2), M (3) and O (5) exhibited weak to moderate anti-Pestalotiopsis theae activity with minimum inhibitory concentration values at the range of 25-100 µg/mL.