data-2025.9.25,Tingting Mao.doc

Species of Trichoderma are among the most widely used microbial biocontrol agents against plant diseases and they are known to produce a wide variety of secondary metabolites that inhibit the growth of the target plant pathogens. The present study aimed to identify inhibitory metabolites produced by Trichoderma hamatum strain MHT1134, shown previously to protect pepper plants against Fusarium wilt. After confirming that the filtered broth from liquid culture of T. hamatum inhibited the growth of the wilt pathogen, three inhibitory compounds were isolated, purified and identified using analytical methods such as TLC, HPLC and nuclear magnetic resonance. CompoundsI (C₈H₇O₄) and III (C₉H₁₂O₃) corresponded to 3(3-hydroxy-cyclopropene 5-one-2-yl)2-propenoic acid and methyl-3-(3-oxocyclopent-1-enyl) propionate, previously reported as secondary metabolites of T. harzianum and T. viride, respectively. Compound II (C₉H₉O₄) was identified as a new polyketide, with a methoxy modification in its structure. The three compounds exhibited a significant inhibitory effect in vitro against F. oxysporum, with inhibition rates of 42.3, 61.9 and 66.2% for I, II and III, respectively, when used at a concentration of 0.010 mg/mL, and 30.1, 41.0 and 46.2% at 0.001 mg/mL, laying a foundation for the further development of biofungicides.