Background: The incidence and prevalence of serious mycoses continues to be a public health problem. These infections are an important cause of morbidity and mortality, especially in immunocompromised patients. The present patent deals with isolation and characterization of a `pure' mixture of two novel isoxazolidinone-containing natural products from two new fungal strains. They have the partial structure of secalonic acid and show very good antifungal activity in mammals and plants and also synergism with other active ingredients. Objective: To analyze the activity of the isoxazolidinone-containing compounds in the present patent. Methods: To review the discovery and development of antifungal compounds in general and secalonic acid related compounds in particular. Conclusion: The research of Parish and collaborators at Merck and Co. has isolated novel antifungal compounds with a new mode of action. These molecules may be considered potential antifungal leads for further clinical study.