Synthesis and biological evaluation of novel trichodermin derivatives as antifungal agents

To discover more potential antifungal agents, 17 novel trichodermin derivatives were designed and synthesized by modification of 3 and 4a. The structures of all the synthesized compounds were confirmed by (1)H NMR, ESI-MS and HRMS. Their antifungal activities against Ustilaginoidea oryzae and Pyricularia oryzae were evaluated. Most of the target compounds showed potent inhibitory activity, in which 4g showed superior inhibitory effects than 4a and commercial fungicide prochloraz. Furthermore, 4h demonstrated comparable inhibitory activity to 4a. Moreover, 4i and 4l exhibited excellent inhibitory activity for Pyricularia oryzae. Additionally, compound 9 was found to be more active against all tested fungal strains than 3, with EC50 values of 0.47 and 3.71 mg L(-1), respectively.