ANTIFUNGAL TESTS IN PHYTOCHEMICAL INVESTIGATIONS - COMPARISON OF BIOAUTOGRAPHIC METHODS USING PHYTOPATHOGENIC AND HUMAN PATHOGENIC FUNGI

The detection limits in two bioautographic assays have been determined for a series of antifungal compounds, including clinically used antim ycotics, fungicidal agrochemicals, and various classes of secondary pl ant metabolites. Target organisms were the filamentous fungus Cladospo rium cucumerinum and the yeast Candida albicans. For clinical agents a nd agrochemicals, the detection limits in the two assays reflected to a certain extent their known spectrum of activity. Most of the plant-d erived compounds tested showed a positive response in both assays, but with detection limits varying by a factor up to tenfold. For screenin g purposes, it is thus advisable to use both tests, as some activities would otherwise go undetected. The MIC values of these substances wer e determined in order to verify a possible correlation with the detect ion limit in the bioautographic assays.