Geniculol, a new biologically active diterpene from the endophytic fungus geniculosporium sp.1

An endophytic fungus of the genus Geniculosporium was isolated from Teucrium scorodonia. The EtOAc extract of this isolate exhibited antialgal activities, as well as demonstrating an interesting profile during chemical screening. After mass cultivation of this fungus, in an optimized agar medium, two of the compounds responsible for the observed biological activity were isolated, the new diterpene geniculol (1), and the known fungal metabolite cytochalasin F (2). Geniculol is an unprecedented and irregular diterpenoid. For 1 and 2 complete 1H and 13C NMR data are reported. Both metabolites exhibit algacidal properties. Additionally, cytochalasin F was shown to be an inhibitor of photosynthesis, suggesting an ecological function in the plant-symbiont relationship for this secondary metabolite.