1.D.37 The Hibicuslide C (Hibicuslide) Family
The antifungal activity and mode of action(s) of hibicuslide C derived from Abutilon theophrasti were investigated by Hwang et al. 2013. Antifungal susceptibility testing showed that hibicuslide C possesses potent activity toward various fungal strains but less hemolytic activity than amphotericin B. The plasma membrane of Candida albicans was perturbed and membrane depolarization resulted from its treatment. Furthermore, model membrane studies were performed with calcein encapsulating large unilamellar vesicles (LUVs) and FITC-dextran (FD) loaded LUVs. Antifungal effects of hibicuslide C on the fungal plasma membrane resulted from the formation of pores with radii between 2.3 nm and 3.3 nm. A reduced cell sizes by the pore-forming action of hibicuslide C were observed. Therefore, hibicuslide C exerts its antifungal effect by pore formation.