Diketopiperazines


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Diketopiperazines

 

six-membered heterocyclic compounds that are piperazine derivatives. They are cyclic anhydrides of ±-amino acids:

Diketopiperazines are colorless crystals. Neutral compounds, they are readily soluble in hot water, but only slightly soluble in cold water. The hydrolysis of diketopiperazines yields dipeptides, then amino acids. Sodium in alcohol reduces diketopiperazines to piperazines.

Diketopiperazines can be made by cyclizing a-amino acids or their esters; they can also be isolated from the hydrolisates of proteins.

References in periodicals archive ?
Cyclo(L-Tyr-L-Pro) (diketopiperazine) and o-hydroxyemodin (anthraquinone) exhibited potent inhibitory effect on HCV NS3-NS4A protease with mild interfere with human physiological processes requiring trypsin activity, which warrants for further investigation of other members of these widely distributed class of diketopiperazines and anthraquinones in marine and terrestrial metabolites.
Chicarelli-Robinson et al., "Inhibition of plasminogen activator inhibitor-1 activity by two diketopiperazines, XR330 and XR334 produced by Streptomyces sp.," Journal of Antibiotics, vol.
Van De Venter, "The biological activity of the histidine-containing diketopiperazines cyclo(His-Ala) and cyclo(His-Gly)," Peptides, vol.
Singh, "Synthesis and antiviral properties of arabino and ribonucleosides of 1,3-dideazaadenine, 4-nitro-1,3-dideazapurine and diketopiperazine," Nucleosides, Nucleotides and Nucleic Acids, vol.
Ampio Pharmaceuticals Inc (Nasdaq:AMPE), a developer of proprietary drugs, announced on Thursday that it has been granted a Canadian patent with broad claims directed to 'METHOD OF USING DIKETOPIPERAZINES AND COMPOSITION CONTAINING THEM'.
Cellular origin of chlorinated diketopiperazines in the dictyoceratid sponge Dysidea herbacea (Keller).
The first patent is directed to a unique class of compounds that combine elements of diketopiperazines (same class as Ampion) and methylphenidate derivatives.