Microbial and Plant Natural Products and Their Antifungal Targets

Fungal infections (dermatophytosis, aspergillosis, cryptococcosis and candidiasis) are considered as one of the prime causes of mortality in immunocompromised individuals including people with advanced age and hospitalization. Numerous compounds with therapeutic properties are produced by medicinal plants and microorganisms. Antifungal targets include cell wall polymers such as glucans, chitin and mannoproteins. Ergosterol biosynthesis in fungal cell membranes, and protein synthesis inhibited by topoisomerases, nucleases, elongation factors and myristoylation are major targets. Inhibition of signal transduction pathway by protein kinases and phosphatases is also important. The present chapter reviews natural compounds that target glucan synthase [(+)-pinene, arundifungin and ascosteoride], chitin production [anthrichitin, nikkomycin Z, phellinsin A, polyoxin A, B and G] and CYP51 [sanguinarine, berberine and tomatidine] which finally lead to the inhibition of ergosterol. Compounds that inhibit fungal sterols [amphotericin B, natamycin, nystatin), lipid metabolism [aureobasidin A, (−)-(E)-dysidazirine, emodin], DNA/RNA [chitosan, parnafungins 1 and 2, yatakemycin], fungal mitochondrial functions [5-fluoro-2-thiopene dehydroabireyl amide, myxocoumarin A, p-coumeric acid], fungal tubulin functions [dolastatin 10, griseofulvin], cell signaling pathway [sampangine] and ion transport [nonactin, monactin, dynactin] have been discussed. Thus, this chapter provides an insight into numerous antifungal natural products synthesized by microbes and plants having diverse modes of action.