Platform for the synthesis and evaluation of verrucarol-based ribosome inhibitors

Trichothecenes are a structurally diverse family of fungal natural products whose potent cytotoxic, antifungal, and immunomodulatory effects make them both a threat to food security and a scaffold for therapeutic development. These sesquiterpenes share a conserved tricyclic core decorated with diverse oxidative and functional modifications, yielding hundreds of known congeners. However, the lack of concise synthetic access to key trichothecenes has limited efforts to systematically interrogate their structure–activity relationships. Here we developed concise, fully synthetic routes to the minimal trichothecenes verrucarol, diacetylverrucarol, and trichodermin. Acetylation of verrucarol markedly enhanced its inhibition of protein synthesis in vitro and increased cytotoxicity toward cancer and non-cancer cell lines, underscoring the role of peripheral modifications in modulating biological activity. Cryo-EM characterization of diacetylverrucarol bound to the human 50S ribosomal subunit at 2.7 Å revealed previously unresolved binding determinants, including bridging water interactions with the G4451 ribose. These results establish a synthetic and structural platform for probing trichothecene structure–function relationships and guiding their optimization for therapeutic applications.