The short version of prothymosin alpha fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-18 and is reviewed periodically as new material appears.
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
Thymosin alpha-1 is a short peptide of 28 amino acid residues first described in the 1970s as a component of thymic extracts. Its N-terminal residue carries an acetyl group, and the sequence is highly conserved across mammalian species. The peptide is not encoded as a standalone gene product; it is released by proteolytic cleavage from the N-terminus of prothymosin alpha, a larger acidic nuclear protein. That precursor relationship places it within a broader family of thymic and immune-associated peptides that have been studied for decades.
The activity of this peptide is generally described as immunomodulatory rather than directly antimicrobial. Experimental work links it to signaling through certain Toll-like receptors on dendritic cells and to downstream maturation of antigen-presenting cells. Reported effects include expansion of T cell subsets, shifts in cytokine profiles, and increased natural killer cell activity. These observations come largely from cell culture and animal models, and the precise receptor-level events in humans remain incompletely characterized.
The compound has been investigated as an adjunct in chronic viral hepatitis and as a vaccine adjuvant, with results that vary by study design and population. Regulators in some countries have approved a synthetic form for specific indications, while other agencies have not. Whether the peptide produces consistent clinical benefit across diverse patient groups is still an open question, and many trials have been small. Its status is therefore best described as investigational in many contexts and established only narrowly.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | Approximately 3,108 Da | Consistent with a 28-residue acetylated peptide |
| Residue count | 28 | Corresponds to the amino terminal region of prothymosin alpha |
| Appearance of dry powder | White to off-white solid | Slight variation between lots is normal |
| Solubility class | Freely soluble in water | Low solubility in most organic solvents |
| Common synonyms | Thymosin alpha 1, T alpha 1 | The numeral reflects an early fraction numbering scheme |
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
Thymosin alpha 1 is a synthetic 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
The lyophilized peptide is generally stable for extended periods when kept cold and dry. Once dissolved, aqueous solutions are less stable; hydrolysis, oxidation, and aggregation can degrade the material. Storage at -20 °C or lower slows these processes. Repeated freeze-thaw cycles are best avoided because they can promote aggregation. The exact shelf life depends on formulation, pH, and concentration, so stability studies are typically performed for each specific product.
Quality control for thymosin alpha-1 focuses on identity, purity, and potency. Identity is confirmed by mass spectrometry and amino acid analysis, while purity is assessed by chromatography with limits on related substances and residual solvents. Potency assays may use cell-based immune readouts, but these are not standardized across laboratories. Regulatory status differs by jurisdiction; no product is approved in the United States for clinical use, whereas some other countries register injectable forms for specific indications.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids whose sequence matches the amino-terminal region of prothymosin alpha. The chain is acetylated at its first residue and contains one disulfide bridge between two cysteine residues, which folds the molecule into a compact loop. Its molecular formula, C129H215N33O55, corresponds to a monoisotopic mass of roughly 3,106 daltons. Material used in laboratories is made by solid-phase synthesis rather than isolated from animal tissue.
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.
=== Side-effects === Although patients at high risk of bleeding were excluded from the phase III clinical study (PROWESS), 25% of patients treated with drotrecogin and 18% of those receiving placebo experienced at least one bleeding event (principally ecchymoses or GI bleeding) during the 28-day study period. During treatment, serious bleeding events (e.g., intracranial hemorrhage, any life-threatening bleeding event, any bleeding event requiring administration of at least 3 units of packed red blood cells daily for 2 consecutive days) occurred in 2.4% of patients treated with drotrecogin and in 1% of those receiving placebo. No significant differences between geriatric patients and younger patients regarding bleeding events in the drotrecogin group were found. No non-bleeding side-effects were observed. A second study, encompassing approximately 1700 adult patients, was completed in 2011 and showed a comparable side-effect profile.
In a more lukewarm review, Kyann-Sian Williams of NME gave the album three stars out of five, complimenting the "raw", introspective lyricism and guest appearances but criticizing Malice's appearances as being preachy and the production as being less innovative then Clipse's previous releases. Alphonse Pierre of Pitchfork also gave a lukewarm review. Scoring the album 6.5 out of ten, Pierre wrote that the duo are "still pretty nice with it on the mic" but deemed Williams's production to be "holding back" the album and boring, describing it as "corporate", "stuffy", and "HR-approved". He cited "M.T.B.T.T.F" as a highlight. Paul Attard of Slant Magazine had similar criticisms, feeling that it was "less like an album and more like a business brief"; he described the production as "devoid of friction" and criticized Clipse's lyricism as being untargeted. Additionally, the album also received 5 nominations at the 2026 Grammy Awards, including nominations for Album of the Year and Best Rap Album.
** not really an RTG, the BES-5 Buk (БЭС-5) reactor was a fast reactor which used thermocouples based on semiconductors to convert heat directly into electricity *** not really an RTG, the SNAP-10A used enriched uranium fuel, zirconium hydride as a moderator, liquid sodium potassium alloy coolant, and was activated or deactivated with beryllium reflectors Reactor heat fed a thermoelectric conversion system for electrical production. **** not really an RTG, the ASRG uses a Stirling power device that runs on radioisotope (see Stirling radioisotope generator)
=== Halide addition === Ethylene oxide readily reacts with aqueous solutions of hydrochloric, hydrobromic, and hydroiodic acids to form halohydrins. The reaction occurs easier with the last two acids:
Sources: en.wikipedia.org
== Categorization == The Rho family of GTPases belong to the Ras superfamily of proteins, which consists of over 150 varieties in mammals. Rho proteins sometimes denote some members of the Rho family (RhoA, RhoB, and RhoC), and sometimes refers to all members of the family. This article is about the family as a whole. In mammals, the Rho family contains 20 members. Almost all research involves the three most common members of the Rho family: Cdc42, Rac1 and RhoA.
Lowered Notch1 expression resulted in no tadpole tail regeneration, and induced Notch1 expression was able to partially rescue tail regeneration in the form of the notochord and spinal cord (but very little musculature.) Moreover, Wnt/beta-catenin activation has shown promising results in its involvement with dedifferentiation. In both a human epithelial cell transplant into mice and in vitro epithelial cell model, the activated canonical Wnt signaling pathway was found to be necessary for dedifferentiation. When in conjunction with Nanog, the canonical Wnt pathway also induced partial dedifferentiation in zebrafish endothelial cells, as seen by an increase in cell cycle re-entry and loss of cellular adhesion.
Below 5 °C (41 °F), the honey will not crystallize, thus the original texture and flavor can be preserved indefinitely. Honey is a supercooled liquid when stored below its melting point, as is normal. At very low temperatures, honey does not freeze solid; rather its viscosity increases. Like most viscous liquids, the honey becomes thick and sluggish with decreasing temperature. At −20 °C (−4 °F), honey may appear or even feel solid, but it continues to flow at very low rates. Honey has a glass transition between −42 and −51 °C (−44 and −60 °F). Below this temperature, honey enters a glassy state and becomes an amorphous solid (noncrystalline).
=== Quality === Semen quality is a measure of the ability of semen to accomplish fertilization. Thus, it is a measure of fertility in a man. It is the sperm in the semen that is the fertile component, and therefore semen quality involves both sperm quantity and sperm quality.
=== Applications === (Q)SAR models have been used for risk management. QSARS are suggested by regulatory authorities; in the European Union, QSARs are suggested by the REACH regulation, where "REACH" abbreviates "Registration, Evaluation, Authorisation and Restriction of Chemicals". Regulatory application of QSAR methods includes in silico toxicological assessment of genotoxic impurities. Commonly used QSAR assessment software such as DEREK or CASE Ultra (MultiCASE) is used to genotoxicity of impurity according to ICH M7. The chemical descriptor space whose convex hull is generated by a particular training set of chemicals is called the training set's applicability domain. Prediction of properties of novel chemicals that are located outside the applicability domain uses extrapolation, and so is less reliable (on average) than prediction within the applicability domain. The assessment of the reliability of QSAR predictions remains a research topic, as a unified strategy has yet to be adopted by modellers and regulatory authorities. The QSAR equations can be used to predict biological activities of newer molecules before their synthesis. Examples of machine learning tools for QSAR modeling include:
Sources: en.wikipedia.org
=== Chemical synthesis === Industrially, aspartate is produced by amination of fumarate catalyzed by L-aspartate ammonia-lyase. Racemic aspartic acid can be synthesized from diethyl sodium phthalimidomalonate, (C6H4(CO)2NC(CO2Et)2).
In December 1990, Iraq made a proposal to withdraw from Kuwait provided foreign troops left the region and that an agreement was reached regarding the Palestinian problem and the dismantlement of Israel's and Iraq's weapons of mass destruction. The White House rejected the proposal. The PLO's Yasser Arafat expressed that neither he nor Saddam insisted that solving the Israel–Palestine issues should be a precondition to solving the issues in Kuwait, though he did acknowledge a "strong link" between these problems. The US and UK stuck to their position there would be no negotiations until Iraq withdrew, and should not grant Iraq concessions, lest they give the impression Iraq benefited from its military campaign. When US secretary of state James Baker met with Tariq Aziz in Geneva, for last minute peace talks in early 1991, Aziz reportedly made no concrete proposals and did not outline any hypothetical Iraqi moves. On 14 January 1991, France proposed that the UN Security Council call for "a rapid and massive withdrawal" from Kuwait along with a statement to Iraq that Council members would bring their "active contribution" to a settlement of the region's other problems, "in particular, of the Arab–Israeli conflict and in particular to the Palestinian problem by convening, at an appropriate moment, an international conference" to assure "the security, stability and development of this region of the world." The proposal was supported by Belgium, Germany, Spain, Italy, Algeria, Morocco, Tunisia, and several non-aligned states.
=== Memory and learning === It has been shown that big dynorphin enhances learning in rodent models through NMDA receptor modulation. This contrasts with the amnestic effects typically associated with opioid receptor agonists and other dynorphins. The mechanism may involve modulation of the NR2B subunit, a modulator of cortical synaptic plasticity and long-term potentiation (LTP).
For most people, 3.5 dried grams (1/8 oz) would be considered a high dose and may produce an intense experience; this is, however, typically considered a standard dose among recreational users. Body composition (usually weight) should be taken into account when calculating dosage. For many individuals, doses above three grams may be overwhelming. For a few rare people, doses as small as 0.25 gram can produce full-blown effects normally associated with very high doses. For most people, however, that dose level would have virtually no effects. There are many different ways to ingest Psilocybe cubensis. Users may prefer to take them raw, freshly harvested, or dried and preserved. It is also possible to prepare culinary dishes such as pasta or tea with the mushrooms. However, the psychoactive compounds begin to break down rapidly at temperatures exceeding 100 °C (212 °F). Another method of ingestion known as "Lemon Tekking" involves combining pulverized Psilocybe cubensis with a concentrated citrus juice with a pH of ~2. Many users believe that a considerable amount of the psilocybin will have been dephosphorylated into psilocin, the psychoactive metabolite, by citric acid. However, this claim is not substantiated by the literature on the metabolism of psilocybin, as dephosphorylation is known to be mediated by the enzyme alkaline phosphatase in humans. It is therefore more likely that citric acid mostly helps in breakdown of mushroom cells, aiding in digestion and psilocybin release.
Sources: en.wikipedia.org
The name reflects an early convention for naming thymus-derived fractions. The peptide is characterized and measured as a defined molecule, and it does not operate through a single classical endocrine axis.
It is usually classified as an immunomodulatory peptide rather than a classical hormone. It derives from the larger protein prothymosin alpha and acts mainly on immune cells. The thymosin label covers a group of distinct peptides, so the naming can be misleading.
The two share a family name but have different sequences, sizes, and functions. Thymosin beta-4 is a 43-residue peptide associated with actin binding and cell migration. Thymosin alpha-1 is a 28-residue peptide linked mainly to immune signaling.
Thymalfasin is the assigned international nonproprietary name for the synthetic 28-residue peptide. Thymosin alpha-1 is the descriptive research name for the same molecule. Which term appears depends on the context and the regulatory document.