Three New Azaphilone Phytotoxins from Coculture of the Phytopathogens Nigrospora oryzae and Colletotrichum gloeosporioides and Antifungal Activities Against N. oryzae

Three new azaphilone phytotoxins, named nigcollins F–H, were isolated from the coculture of the phytopathogens Nigrospora oryzae and Colletotrichum gloeosporioides . Phytotoxins and other metabolites also indicated antifungal activity against phytopathogens, endophytes, and entomopathogen. Interestingly, the production of phytotoxins by N. oryzae and its phytopathogenicity can be eliminated by coculture the phytopathogen N. oryzae with the host plant Dendrobium officinale . The host D. officinale could discriminate phytopathogens and probiotics by exhibiting selective antipathogen activity.