Amino Acids and Dipeptides
30 compounds in this family, each with its recorded mechanism, routes of administration, safety notes and references to published literature.
- ACV tripeptideDelta‑(L‑α‑aminoadipyl)‑L‑cysteinyl‑D‑valine (ACV) is a non‑ribosomal tripeptide intermediate produced by fungi and some bacteria during the early steps of β‑lactam antibiotic biosynthesis. It is the first dedicated precursor that is converted into isopenicillin N and subsequently into penicillins and cephalosporins, making it central to industrial production of these drugs.
- Alanyl glutamineAlanyl‑glutamine (AG) is a dipeptide composed of alanine and glutamine that is approved as a prescription amino‑acid supplement. It can be given intravenously, orally, or added to peritoneal dialysis fluids. Research explores its role in supporting cellular stress responses, improving fluid retention, reducing postoperative adhesions, and potentially protecting the peritoneal membrane during dialysis.
- Aminolevulinic acid5‑Aminolevulinic acid (ALA) is a prescription amino‑acid precursor of porphyrins used orally or topically. In neurosurgery it is administered before resection of malignant glioma to cause tumour cells to fluoresce, aiding more complete removal. Topically, ALA serves as a photosensitiser in photodynamic therapy (PDT) for skin disorders such as acne and psoriasis. Its dual routes allow both systemic and local applications, but clinical benefits vary across indications.
- Arginine glutamateArginine glutamate is an approved prescription amino‑acid salt composed of L‑arginine and L‑glutamate. It is supplied for intravenous or oral use and is investigated chiefly for supporting liver‑related metabolic disorders such as mild hepatic encephalopathy, where it may help lower blood ammonia and improve neurological function.
- AspartameAspartame is an oral, over‑the‑counter dipeptide sweetener (L‑aspartyl‑L‑phenylalanine methyl ester) that is about 200 times sweeter than sucrose. It is used in a wide range of foods, drinks, and pharmaceuticals to provide sweetness with few calories, and is approved for general consumption in many countries.
- AvizafoneAvizafone is a water‑soluble dipeptide prodrug of the benzodiazepine diazepam. It is being investigated for rapid seizure control in emergency settings such as status epilepticus or organophosphate poisoning. The compound is administered intramuscularly or intravenously, often together with an enzyme that converts it to active diazepam, and is also studied for intranasal delivery using a prodrug‑enzyme mixture.
- CarnosineCarnosine (β‑alanine‑L‑histidine) is a naturally occurring dipeptide found in skeletal muscle and brain tissue. It can be taken orally or applied topically as a supplement. In humans it is synthesized from the essential amino acid histidine and the non‑essential β‑alanine, and is studied for its intracellular buffering, antioxidant, anti‑glycation and metal‑chelating properties, as well as for potential benefits in exercise performance and various health conditions.
- DarinaparsinDarinaparsin is an organoarsenic drug composed of dimethylated arsenic linked to glutathione. It is approved in Japan for the treatment of relapsed or refractory peripheral T‑cell lymphoma (PTCL) and is administered intravenously. Clinical studies have shown modest response rates in this difficult‑to‑treat disease, with a safety profile that includes cytopenias and hypertension.
- EzatiostatEzatiostat (TLK199) is an investigational glutathione‑analog prodrug that inhibits the enzyme glutathione‑S‑transferase P1‑1 (GSTP1‑1). It is being evaluated for the treatment of myelodysplastic syndromes (MDS), a group of bone‑marrow disorders that cause ineffective blood‑cell production. By modulating oxidative‑stress pathways and promoting maturation of hematopoietic progenitors, ezatiostat aims to improve red‑cell, white‑cell and platelet counts and reduce the need for transfusions.
- gamma-GlutamylcysteineGamma‑glutamylcysteine (γ‑GC) is a dipeptide composed of glutamate linked to cysteine. It is the immediate biosynthetic precursor of the tripeptide glutathione (GSH) and occurs naturally in many organisms, including humans, archaea and some bacteria. In research settings γ‑GC is investigated for its ability to raise intracellular GSH levels and thereby support antioxidant defenses, redox signaling, and cellular health.
- GlutathioneGlutathione is a naturally occurring tripeptide that functions as a cellular antioxidant and is marketed in various forms for skin lightening. Clinical investigations have examined oral capsules (250–500 mg daily), topical creams (0.5–2 % concentrations), and intravenous infusions, primarily aiming to reduce melanin levels in sun‑exposed skin and improve hyperpigmentary conditions such as melasma.
- Glutathione disulfideGlutathione disulfide (GSSG) is the oxidized dimer of the tripeptide glutathione (GSH). It forms when two GSH molecules donate electrons to neutralise reactive species, creating a disulfide bond. In research settings GSSG is examined as a marker of cellular oxidative stress, a source of cysteine after reduction, and a component of the redox couple that influences ageing, neurodegeneration and cancer‑related ferroptosis.
- GlutathionylspermidineGlutathionylspermidine (Gsp) is a naturally occurring conjugate of glutathione and the polyamine spermidine. It is found in many bacteria and in kinetoplastid parasites such as Trypanosoma and Leishmania, where it serves as a precursor to the dithiol trypanothione system that replaces glutathione in redox balance and detoxification.
- GlycylglutamineGlycylglutamine is a dipeptide comprising glycine and glutamine that serves as a stable source of glutamine when added to parenteral nutrition. It has been investigated primarily in surgical and oncology settings to support protein metabolism, improve nitrogen balance, and reduce postoperative complications.
- GlycyltyrosineGlycyl‑tyrosine (Gly‑Tyr) is a dipeptide composed of glycine linked to the aromatic amino acid tyrosine. In research settings it has been examined as a source of tyrosine in parenteral nutrition formulations and as a conjugate partner for bile acids. Studies in rats and humans have explored its intestinal absorption, plasma appearance after intravenous infusion, and its contribution to nutritional outcomes in malnourished patients undergoing hemodialysis.
- KPVKPV (Lys-Pro-Val) is a C-terminal tripeptide fragment of alpha-melanocyte-stimulating hormone (α-MSH) with potent anti-inflammatory properties. It lacks the melanotropic activity of full-length α-MSH while retaining immunomodulatory effects, making it a candidate for inflammatory and autoimmune conditions.
- MurabutideMurabutide is a synthetic analogue of muramyl dipeptide, classified as an immunomodulatory peptide. It is being investigated as an adjuvant to boost vaccine‑induced immunity and as a non‑specific immunotherapy for chronic viral infections such as HIV. The compound is administered by injection (intravenous or subcutaneous) in investigational clinical studies.
- N-(3-Propylcarbamoyloxirane-2-Carbonyl)-Isoleucyl-ProlineN-(3-Propylcarbamoyloxirane-2-Carbonyl)-Isoleucyl-Proline (also known as POPHA or Compound Z-Pro-Prolinal analogue in some literature, most commonly referenced as the prolyl endopeptidase inhibitor Eurystatin A or a close structural analogue) is a naturally-derived or synthetic epoxide dipeptide that potently and irreversibly inhibits prolyl oligopeptidase. It has been used extensively as a research tool to study the role of POP in neuropeptide metabolism, cognition, and neurological disorders. No approved clinical indication exists; it is used primarily in in vitro and animal studies.
- NOV-002NOV-002 is an investigational glutathione disulfide (GSSG) mimetic studied as an adjunct to chemotherapy for solid tumours. Administered by intravenous or subcutaneous injection, it is intended to modulate cellular redox balance, enhance anti‑tumour efficacy and lessen chemotherapy‑induced hematologic toxicity.
- OrnithineOrnithine is a conditionally essential amino acid that occurs naturally in the body and in various organisms. It is a component of bacterial membrane lipids, a substrate in the urea cycle, and is formulated together with L‑aspartate (LOLA) for medical use. Research has explored its role in liver disease, imaging agents, and as a nutritional supplement in wound care.
- PolaprezincPolaprezinc is an oral prescription drug consisting of a zinc‑carnosine chelate. It is approved primarily for the treatment of gastric ulcers and as a zinc‑replacement therapy. The compound combines zinc with the dipeptide carnosine, delivering zinc directly to injured gastrointestinal mucosa while providing antioxidant and cytoprotective effects. Clinical research has examined its role in correcting zinc deficiency, enhancing Helicobacter pylori eradication when added to standard triple therapy, and supporting mucosal healing in various gastrointestinal disorders.
- S-(2,4-dinitrophenyl)glutathioneS-(2,4-dinitrophenyl)glutathione (DNP‑SG) is a synthetic glutathione‑S‑conjugate used primarily as a model substrate in biochemical research. It enables the study of ATP‑dependent transport systems that move glutathione conjugates across cellular membranes, such as the canalicular bile‑acid transporter in rat liver, plant vacuolar transporters, and the RLIP76 protein in mammalian cells.
- S-(4-nitrobenzyl)glutathioneS-(4-nitrobenzyl)glutathione is a glutathione‑derived thioether formed when the environmental contaminant 4‑nitrotoluene is metabolised in rat liver. In laboratory settings it serves as a research probe for studying glutathione‑transferase (GST) enzymes, especially the phi‑class GSTs that confer multiple‑herbicide resistance in weeds, and it has been listed among compounds that influence metal accumulation in phytoremediation experiments.
- S-(N-hydroxy-N-bromophenylcarbamoyl)glutathioneS-(N-hydroxy‑N‑bromophenylcarbamoyl)glutathione is a synthetic glutathione derivative employed primarily as a biochemical tool. It mimics the natural substrate S‑D‑lactoylglutathione and acts as a competitive inhibitor of human glyoxalase II, the enzyme that hydrolyses S‑D‑lactoylglutathione in the glyoxalase detoxification pathway. The compound is used in enzymatic assays and structural studies to elucidate the catalytic mechanism and substrate‑binding interactions of glyoxalase II.
- S-benzylglutathioneS‑benzylglutathione is a synthetic analogue of the tripeptide glutathione. In research it is employed as a structural probe and inhibitor of enzymes that use glutathione, such as glyoxalase I, glutathione S‑transferases (GSTs), and γ‑glutamyltransferase, and as a tool to study glutathione transport across cell membranes. It is not an approved drug and is used only in vitro or in animal experiments.
- S-HexylglutathioneS‑Hexylglutathione is a synthetic thioether analogue of the tripeptide glutathione. It is employed primarily as a research tool to probe the active sites of glutathione‑dependent enzymes, especially class π glutathione S‑transferases (GSTP1‑1), and to create affinity matrices for protein purification. By mimicking glutathione while adding a hydrophobic hexyl chain, it serves as a competitive inhibitor and stabilising ligand in structural and biochemical studies.
- S-Methyl glutathioneS‑Methyl glutathione (GSMe) is a chemically modified analogue of the tripeptide glutathione in which the cysteine thiol is methylated. It can arise from chemical alkylation or enzymatic methylation in bacteria and has been detected in human plasma, where its concentration rises in acute myocardial infarction. Research use is limited to in‑vitro, ex‑vivo and analytical applications; it is not an approved therapeutic agent.
- S-NitrosoglutathioneS‑Nitrosoglutathione (GSNO) is an endogenous S‑nitrosothiol that serves as a carrier and donor of nitric oxide (NO). It is being investigated for its broad‑spectrum antimicrobial properties, its role in redox signalling, and as a potential therapeutic NO donor in respiratory and wound‑healing applications. Current research focuses on incorporating GSNO into biomaterials, nano‑formulations, and inhalation therapies to exploit its antimicrobial activity while maintaining biocompatibility.
- S-octylglutathioneS‑octylglutathione (also called GS‑8, GSO8, or octyl‑GSH) is a synthetic analogue of the tripeptide glutathione in which the cysteine thiol is alkylated with an octyl chain. In research, it is employed primarily as a competitive inhibitor of glutathione S‑transferases (GSTs) and related enzymes such as glyoxalase I. By blocking GST activity, it helps investigators probe the role of these detoxifying enzymes in lipid peroxidation, xenobiotic metabolism, and the biotransformation of specialized compounds like the explosive CL‑20.
- TrypanothioneTrypanothione (N1,N8-bis(glutathionyl)spermidine) is a dithiol molecule unique to trypanosomatid parasites such as Trypanosoma and Leishmania. It acts as the primary intracellular redox buffer, supplying electrons to parasite‑specific peroxidases and other antioxidant enzymes, thereby protecting the organism from oxidative damage.