Fungicidal Activity of Secondary Metabolites from Trichoderma hamatum B-3

Two new harziane diterpenes (1-2), five undescribed cyclonerane sesquiterpenes (3-7) and three known compounds, 11-cycloneren-3,7,10-triol (8), harziandione (9), and dehydroacetic acid (10) were isolated from Trichoderma hamatum b-3. Their structures were elucidated via comprehensive inspection of spectral evidences in HRESIMS, 1D and 2D NMR, the absolute configuration of 1-8 was confirmed by NMR, ECD calculation as well as Mosher's method. In vitro fungicidal activity showed that some compounds showed great inhibitory activity against pathogenic fungi including Fusarium graminearum, Sclerotinia sclerotiorum, Botrytis cinerea, and Rhizoctonia solani, among which compound 10 showed 100% inhibition of S. sclerotiorum and B. cinerea. In vivo activity test showed that compound 10 was 65.8% effective against B. cinerea and has the potential to be developed as a biocontrol pesticide.