Phomopsidin, a new inhibitor of microtubule assembly produced by Phomopsis sp. isolated from coral reef in Pohnpei.

antitumor and antifungal agents. Recently, curacin A, which is a potential antitumor agent, was isolated from marine cyanobacterium (blue-green alga) Lyngbya majuscula as an antimitotic cytotoxic component.1} We have reported an effective assay method for antimitotic substances, which observes deformations of mycelia germinated from conidia of Pyricularia oryzae P-2b, and certain antimitotic compounds can be detected by the characteristic curling effect of the mycelia.2) Curacin A, which inhibits the assembly of microtubule proteins, showed the curling effect. This bioassay method has been applied to fermentation broths of filamentous fungi isolated from marine environments (invertebrates, algae, submerged materials and so on) in Pohnpei and Palau. A new antimitotic component 1 has been isolated from a fungal strain TUF 95F47. Wedescribe here the isolation and fermentation of the fungus and isolation, structure, and biological