Cyclic Peptides
8 compounds in this family, each with its recorded mechanism, routes of administration, safety notes and references to published literature.
- ArgifinArgifin is a naturally occurring cyclic pentapeptide that inhibits family‑18 chitinases. Isolated from soil‑derived fungi, it is used in research to probe chitinase function and as a lead scaffold for antifungal, insecticidal and anti‑asthma strategies. It is not an approved drug and remains a laboratory tool.
- Aspartyl-alanyl-diketopiperazineAspartyl-alanyl-diketopiperazine (DA‑DKP) is a cyclic dipeptide fragment generated from the N‑terminus of human serum albumin during commercial preparation. Laboratory studies have shown that DA‑DKP can suppress activation‑induced cytokine release from human peripheral blood mononuclear cells and T‑lymphocytes, suggesting an immunomodulatory role. The compound is not an approved drug and has only been examined in vitro.
- CMX-2043CMX-2043 is an investigational synthetic analogue of α‑lipoic acid designed as a cytoprotective agent. It is being studied for its ability to limit tissue damage caused by ischemia‑reperfusion and traumatic injury, with research focusing on cardiac procedures such as percutaneous coronary intervention (PCI) and on traumatic brain injury (TBI). The compound is administered by injection, primarily intravenously, and is not yet approved for any therapeutic indication.
- Cyclo(his-pro)Cyclo(His-Pro) (also called CHP or cyclo(L-histidyl-L-proline)) is an endogenous cyclic dipeptide found in blood, cerebrospinal fluid, brain and other tissues. Research, largely pre‑clinical, has explored its ability to modulate oxidative stress, inflammation and protein‑folding pathways, suggesting a potential role in protecting neurons from degeneration seen in disorders such as amyotrophic lateral sclerosis and other protein‑misfolding diseases.
- Cyclo(prolylglycyl)Cyclo(prolylglycyl) (also called cyclo(L‑Pro‑Gly)₃) is a synthetic cyclic hexapeptide composed of three repeats of the Pro‑Gly dipeptide, forming a diketopiperazine ring. Research to date has focused on its solid‑state characteristics, including crystal packing and its ability to bind calcium ions. The compound is classified as a research‑only cyclic dipeptide and has no approved therapeutic use.
- CyclosporineCyclosporine is a cyclic non‑ribosomal peptide that acts as a calcineurin inhibitor. It is an approved prescription drug given orally, intravenously, ophthalmically, or topically. Clinically it prevents organ‑allograft rejection and treats immune‑mediated kidney disease, severe ulcerative colitis, atopic dermatitis and certain dermatologic conditions. Its immunosuppressive properties stem from inhibition of T‑cell activation, making it a cornerstone in transplantation and a therapeutic option for refractory inflammatory disorders.
- Cyclotheonamide ACyclotheonamide A (CtA) is a cyclic pentapeptide isolated from marine sponges of the genus Theonella. In laboratory studies it acts as a slow‑binding inhibitor of several trypsin‑like serine proteases, most notably human alpha‑thrombin and bovine trypsin. The compound is used in research to explore protease inhibition and the molecular basis of coagulation, but it has not progressed to clinical use.
- PegcetacoplanPegcetacoplan is a pegylated cyclic peptide that inhibits complement component C3. It is approved for treating paroxysmal nocturnal hemoglobinuria (PNH) and is being investigated for dry age‑related macular degeneration (geographic atrophy) and complement‑mediated kidney disorders such as C3 glomerulopathy and immune‑complex membranoproliferative glomerulonephritis.