The 2,5-diketopiperazines (DKPs) are the smallest cyclopeptides and their basic structure
includes a six-membered piperazine nucleus. Typical peptides lack a special functional
group in the oligopeptide nucleus. Both are produced by at least 35 representative
genera of fungi, and possess huge potential as pharmaceutical drugs and biocontrol
agents. To date, only cyclosporin A has been developed into a commercial product.
This review summarises 186 fungi-derived compounds reported since 2000. Antibiotic
(antibacterial, antifungal, synergistic antifungal, antiviral, antimycobacterial,
antimalarial, antileishmanial, insecticidal, antitrypanosomal, nematicidal and antimicroalgal)
activities are discussed for 107 of them, including 66 DKPs (14 epipolythiodioxopiperazines,
20 polysulphide bridge-free thiodiketopiperazines, and 32 sulphur-free prenylated
indole DKPs), 15 highly N-methylated, and 26 non-highly N-methylated typical peptides.
Structure-activity relationships, mechanisms of action, and research methods are covered
in detail. Additionally, biosynthases of tardioxopiperazines and neoechinulins are
highlighted. These compounds have attracted considerable interest within the pharmaceutical
and agrochemical industries.