New Polyketides From Trichoderma harzianum and Their Antifungal Activity

ABSTRACT 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.