Fungal symbionts of marine organisms: The case of Cladosporium and its bioactive secondary metabolites.

Fungi in the genus Cladosporium (Dothideomycetes, Cladosporiaceae) are widespread in every kind of natural and anthropic terrestrial habitats, where they are reported to be involved in ecological interactions. The developments in marine mycology have demonstrated that, rather than being typically terrestrial, they are also common in the sea. In this manuscript, we examined the synthetic potential of Cladosporium strains recovered from marine organisms and the available information concerning bioactivities of their secondary metabolites. As many as 106 compounds have been identified as products of these fungi so far, belonging to several classes of natural compounds, such as benzopyrones, diketopiperazines, flavonoids, lactones, macrolides, naphthalenones, pyrones, steroids, tetramic acids, and xanthones; 29 of them were first identified from this biological material, representing a valuable source of chemodiversity, which deserves to be investigated in-depth for the related biological properties in view of possible biotechnological exploitation.