The short version of Thymosin fraction 5 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-18 and is reviewed periodically as new material appears.
Early work on thymic extracts in the 1960s described a heat-stable acidic fraction containing many polypeptides. Separation of that mixture yielded individual components, and thymosin alpha-1 was named as one of them on the basis of assays for T-cell activity. The first preparations came from calf thymus, while subsequent research and clinical material has been chemically synthesized. Nomenclature in older papers is inconsistent, and the same peptide sometimes appears under different designations, which complicates literature searches.
Most published studies on thymosin alpha-1 report changes in immune measurements rather than clinical outcomes, and findings differ across designs and populations. Whether the peptide signals through one defined receptor or through several less specific interactions remains an open question. Its reported circulation half-life of a few hours complicates comparison of dosing schedules across trials. Mechanistic claims are frequently drawn from isolated cell cultures, and how far those results extend to whole organisms is unresolved.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | 28 residues; not a small-molecule compound |
| Molecular mass | About 3,106 Da | Monoisotopic mass of the unmodified chain |
| N-terminal group | Acetylated serine | Present in both native and synthetic forms |
| Secondary structure | Disulfide-constrained loop | One bridge between two cysteine residues |
| Typical source | Solid-phase synthesis | Early isolates came from bovine thymus extracts |
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
Food and Drug Administration (FDA) New Dietary Ingredient (NDI) notification, evaluated under Australia's Therapeutic Goods Administration (TGA) ingredient framework, and is protected by multiple international patent applications related to banana peel extract and its applications.
== Other animals == Bowed tendon is a term for form of tendinitis (inflammation) and tendinosis (degeneration) most commonly seen in the superficial digital flexor tendon in the front leg of horses. Mesenchymal stem cells, derived from a horse's bone marrow or fat, can be used for tendon repair in horses.
==== Absorption ==== Following oral administration of lisinopril, peak serum concentrations of lisinopril occur within about seven hours, although there was a trend to a small delay in time taken to reach peak serum concentrations in acute myocardial infarction patients. The peak effect of lisinopril is about 6 hours after administration for most people. Declining serum concentrations exhibit a prolonged terminal phase, which does not contribute to drug accumulation. This terminal phase probably represents saturable binding to ACE and is not proportional to dose. Lisinopril does not undergo metabolism and the absorbed drug is excreted unchanged entirely in the urine. Based on urinary recovery, the mean extent of absorption of lisinopril is approximately 25% (reduced to 16% in people with New York Heart Association Functional Classification (NYHA) Class II–IV heart failure), with large interpatient variability (6 to 60%) at all doses tested (5 to 80 mg). Lisinopril absorption is not affected by the presence of food in the gastrointestinal tract. Studies in rats indicate that lisinopril crosses the blood-brain barrier poorly. Multiple doses of lisinopril in rats result in little or no accumulation in brain tissue.
Sources: en.wikipedia.org
In 1950, as a representative of the Cambodia communist, Son Ngoc Minh met Viet Minh's representatives at Hatien, southern Vietnam, which near Cambodian border. He analysed the revolutionary situation in Cambodia and stated due to the weak "principle force", Cambodia could hardly have a revolution. In April 17–19, 1950, the "First National Congress of Khmer Resistance" was held in Kampot, Cambodia. On the meeting, United Issarak Front and People's Liberation Central Committee (PLCC) was founded. Minh was the president of the PLCC. Two months later, as the Viet Minh guided-Issarak controlled one third of the Cambodian territory, Minh declared Cambodia's independence, three years before Sihanouk's government gained independence from France.
== Current status == Antimicrobial resistance is the driving force for the development of new antimicrobial agents. The complexity and diversity of resistance mechanisms has defined the need for new and improved β-lactam antibiotics. With their broad spectrum the cephalosporins have come to dominate β-lactam chemotherapy although they often lack oral bioavailability. On 29 October 2010, a new cephalosporin agent - Ceftarolin - was approved by the food and drug administration (FDA). Teflaro (ceftaroline fosamil) is an injectable antibiotic prodrug to treat adults with acute bacterial skin and skin structure infections (ABSSI) and community acquired bacterial pneumonia (CABP). Ceftobiprole has been approved for the treatment of adult patients with hospital acquired pneumonia (excluding VAP) and community acquired pneumonia in 12 European countries, Canada and Switzerland.
== Contraindications == It is contraindicated if there has been a past history of angioedema; heart conduction disorders (e.g. sick sinus syndrome, second- or third-degree heart block); bradycardia; severe heart failure or coronary artery disease. Also: Raynaud's syndrome, intermittent claudication, epilepsy, depression, Parkinson's disease, glaucoma. Use in pregnancy is discouraged. Moxonidine passes into breast milk. Moxonidine should be avoided in patients with moderate to severe renal impairment. Abrupt discontinuation of the drug should also be avoided. If concomitant treatment with a beta blocker has to be stopped, the beta blocker should be discontinued first, then moxonidine after a few days. Alcohol may potentiate the hypotensive effects of Moxonidine. Excess mortality has been seen in patients with symptomatic heart failure in the MOXCON study. However, the MOXCON trial utilised a very high dose of 3.0 mg daily which is well above the normal dose of 0.2–0.6 mg daily.
Sources: en.wikipedia.org
Cysteine is the rate-limiting substrate in the synthetic pathway for glutathione in the eye. Glutathione is an antioxidant that protects crystallins in the eye from reactive oxygen species; denatured crystallins can lead to cataracts. Cystathionase is also a target for reactive oxygen species. Thus as cystathionase is oxidized, its activity decreases, causing a decrease in cysteine and, in turn, glutathione in the eye, leading to a decrease in antioxidant availability, causing a further decrease in cystathionase activity. Deficiencies in cystathionase activity have also been shown to contribute to glutathione depletion in patients with cancer and AIDS. Mutations and deficiencies in cystathionase are associated with cystathioninuria. The mutations T67I and Q240E weaken the enzyme's affinity for pyridoxal phosphate, the co-factor vital to enzymatic function. Low levels of H2S have also been associated with hypertension in mice. Excessive levels of H2S, due to increased activity of cystathionase, are associated with endotoxemia, acute pancreatitis, hemorrhagic shock, and diabetes mellitus.
Disposal of plutonium waste from nuclear power plants and dismantled nuclear weapons built during the Cold War is a nuclear-proliferation and environmental concern. Other sources of plutonium in the environment are fallout from many above-ground nuclear tests, which are now banned.
== Species distribution == Carboxypeptidase E is found in all species of vertebrates that have been examined, and is also present in many other organisms that have been studied (nematode, sea slug). Carboxypeptidase E is not found in the fruit fly (Drosophila), and another enzyme (presumably carboxypeptidase D) fills in for carboxypeptidase E in this organism. In humans, CPE is encoded by the CPE gene.
=== 2005–present: A new look === On 17 December 2005, the organisation obtained a new corporate identity. The previous NOS logo was in use for 36 years and featured the company's initials in lowercase, with round and obtuse angles. The O of the logo is painted red and represents "the hub of 360-degree reportage". The new logo was designed by graphic designers Lambie-Nairn, complete with new idents for its television programmes. The typeface was Gotham. Its news-gathering operations also changed, with the news departments for radio, television, and internet merging and reorganising into different sections (NOS, NOS News, NOS Sports, with NOS Events added in 2009). An announcement made by the Minister of Education in 2007 confirmed a further division of the NOS. The umbrella group Publieke Omroep, managed by the NOS was to be legally separated and renamed Nederlandse Publieke Omroep (Netherlands Public Broadcasting). The move was to ensure the NOS operated under the same conditions as its fellow broadcasting associations, as well as transferring membership of the European Broadcasting Union. In 2009, the NOS became fully independent and now has its own Board of Directors. Since 2012, the NOS has got a new style and layout and, for some programs, other titles. The biggest change is visible in the 8 o'clock NOS Journaal (traditionally the most viewed and therefore the most important news broadcast of the NOS), where they adopted a standing presentation.
Sources: en.wikipedia.org
Its sequence corresponds to the amino-terminal portion of prothymosin alpha, a larger protein present in many cell types. The isolated 28-residue peptide is a fragment of that protein rather than a separately encoded molecule, and laboratory material is produced by synthesis.
The single bridge between two cysteine residues holds the chain in a folded loop that influences its shape and its behavior in solution. Loss of the bridge through reduction or oxidation shifts chromatographic retention and is tracked during stability work.
It is a defined 28-residue sequence derived from a larger precursor, whereas many other thymic preparations are mixtures of several polypeptides. Its acetylated amino terminus and single disulfide bridge distinguish it chemically from unrelated thymic extracts.
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.