Research progress on activity and biosynthesis of diketopiperazines

Diketopiperazines (DKPs) are mainly produced by microorganisms. In recent years, active natural products with DKPs structure have been isolated from marine bacteria, actinomycetes and fungi. The stable six-membered ring framework makes DKPs a vital pharmacophore in medicinal chemistry. Several recent studies have demonstrated that it has antibacterial, antifungal, antiviral, antitumor, immunosuppressive, neuroprotective, anti-malaria, anti-prion, and anti-hyperglycemia properties. Some DKPs are signaling molecules for intercellular communication, which can activate or inhibit bacterial Lux R-mediated quorum sensing. They are considered potential new anti-infective drugs that could control biofilm formation by interfering with information communication between microbes. DKPs possess excellent biological activities and have received extensive attention from medicinal chemistry workers. Bioactivity studies of DKPs have revealed that many highly active lead compounds exist in antibacterial, antitumor, and antiviral fields and in treating neurological disorders. This paper reviews the research progress of diketopiperazines in the past ten years.