Biological activity of fungal secondary metabolites

Fungi are cosmopolitan organisms that inhabit almost all ecological niches of the earth and have the ability to utilise various substrates as a consequence of diversity of their biological and biochemical evolution. Fungi, during their development, follow different metabolic pathways that led to production of numerous intermediate and/or end-product compounds called as secondary metabolites. Fungi, filamentous forms, produce a diverse array of secondary metabolites that are small molecules, and not necessary for normal growth or development. Secondary metabolites have a tremendous impact on society; some are exploited for their antibiotic and pharmaceutical activities, others are involved in disease interactions with plants or animals. Most fungal secondary metabolites are synthesised from only a few key precursors in pathways that comprise a relatively small number of reactions and which branch off from primary metabolism at a limited number of points. However, the roles of secondary metabolites in the fungi that produce them are still more or less a mystery.