Effect of taxol and related compounds on growth of plant pathogenic fungi

Taxol, currently in use as therapy for refractory ovarian cancer, has no known function in the plant (Taxus brevifolia) from which it is isolated. In an effort to explore its biological role, we investigated the effect of Taxol and related compounds on the growth of plant pathogenic fungal hyphae. Taxol and cephalomannine inhibited the growth of several fungi, especially Ptytophthora and Pythium species (Oomycetes) and Rhizoctonia solani (Basidiomycetes). Baccatin III had no effect on the growth of any fungus tested. Strains of Aspergillus (Deuteromycetes) and Fusarium (Ascomycetes) were not inhibited by any taxane. As little as 1.0 nmol of Taxol or cephalomannine severely retarded radial growth of Phytophthora species on solid medium