Detection of antifungal compounds using lc microfractionation and bioautography with a hypersusceptible strain of C. albicans0
There is an urgent need for new antifungal drugs due to the increase of invasive fungal infections and the appearance of multidrug-resistant strains. In this context, we have developed an efficient strategy for a rapid identification of potential antifungal agents in crude plant extract. The method combines HPLC-microfractionation in 96-well plates and subsequent bioautography for tracking the bioactive compounds with high resolution LC separation. In order to improve the sensitivity of the assay for the detection of potentially interesting minor bioactive natural products, a sensitive engineered strain of C. albicans (DSY2621) hypersusceptible to known drugs was used. This procedure enabled a precise localization of the antifungal compounds directly in the crude extracts present at very low concentrations. In parallel an efficient chemical screening using LC-PDA-ELSD-MS and microflow NMR provided and efficient dereplication known compounds. This approach has been applied to a large series of plant extracts and allowed a rapid and efficient identification of potential antifungal compounds.