A practical reference on reversed-phase HPLC: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-18 and is reviewed periodically as new material appears.
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.
在信号层面，Tα1可能通过Toll样受体等模式识别受体发挥作用。部分实验显示，它能激活髓样分化因子88依赖的通路，进而促进核因子κB进入细胞核。这导致白细胞介素2、干扰素γ和白细胞介素12等细胞因子的转录增加。这些细胞因子偏向辅助性T细胞1型应答，有助于细胞免疫。然而，具体受体和结合位点尚未完全确定，不同实验模型的结果存在差异。
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
胸腺素α1对免疫系统的影响涉及多种细胞类型。研究表明，它可促进未成熟T细胞向成熟T细胞分化，并增强T细胞对抗原刺激的增殖反应。树突状细胞在Tα1存在下表达更高水平的共刺激分子，从而更有效地呈递抗原。此外，自然杀伤细胞的活性也观察到上升。这些效应并非直接杀伤病原体，而是调节宿主免疫应答的强度与方向。
| 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 |
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.
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.
Identity and purity are assessed with a small set of standard peptide methods. Reversed-phase high-performance liquid chromatography separates the main peak from truncated or oxidized species, and its area percentage is the usual purity measure. Mass spectrometry confirms the observed molecular mass against the expected value, while amino acid analysis or peptide mapping checks composition and sequence. Specifications for research-grade material are often stated as 95 percent or higher, though the exact limit depends on the supplier and the intended use.
Laboratory supplies of the peptide usually arrive as a lyophilized powder in sealed vials. The powder is hygroscopic, so a vial should be allowed to reach room temperature before it is opened to prevent condensation on the contents. Weighing and transfer are best performed in a low-humidity environment with clean tools. Once dissolved, the solution should be mixed gently rather than vortexed, because foaming and shear can reduce recovery of the peptide.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
Overall evidence quality varies considerably. A large share of published reports come from single centers, rely on surrogate immunological markers, or lack adequate control groups. Systematic reviews have highlighted this heterogeneity as a barrier to pooling results. Open questions include which patients, if any, might benefit, what treatment duration is appropriate, and whether any effect is independent of standard care. The peptide is often described as an immune modulator rather than a therapy for one disease, which complicates confirmatory trial design.
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
Lyophilized thymosin alpha-1 is generally stored at or below minus twenty degrees Celsius, protected from moisture and light. Short-term handling at ambient temperature is possible for dry powder, but reconstituted solutions degrade faster and are usually kept at two to eight degrees Celsius with a defined expiry of days rather than weeks. Repeated freeze-thaw cycles should be avoided because they promote aggregation and loss of potency. Exact limits depend on the formulation and should follow the supplier's documentation.
Identity and purity are normally assessed by reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities and truncation products. Mass spectrometry confirms molecular mass and detects modifications such as deamidation or oxidation. Amino acid analysis and peptide mapping provide additional sequence-level confirmation. For research material, a certificate of analysis typically reports these results together with water content and counter-ion identity, since the lyophilized powder is often supplied as an acetate or trifluoroacetate salt.
=== Legal status === It was approved in both the European Union (brand name Revestive) and the United States (brand name Gattex) in 2012. It was granted orphan drug designation by the European Medicines Agency (EMA).
== Nutrition == A study by the National University of Singapore showed that Chinese dark soy sauce contains 10 times the antioxidants of red wine. Unpasteurized soy sauce is rich in lactic acid bacteria and of excellent anti-allergic potential. Soy sauce does not contain the level of isoflavones associated with other soy products, such as tofu or edamame. It can also be very salty, having a salt content between 14 and 18%. Low-sodium soy sauces are made, but it is difficult to make soy sauce without using some quantity of salt as an antimicrobial agent. A serving of 100 millilitres (3.5 imp fl oz; 3.4 US fl oz) of soy sauce contains, according to the USDA:
Endotoxins are negatively charged, and will bind to an anion exchanger. If the target substance is not also negatively charged, it will pass through the column before the endotoxin, and an effective separation can be achieved. This method is sometimes used in the purification of albumins (details follow). Ligands of known affinity to endotoxins can be coupled to an anion exchange system to increase its endotoxin binding strength and further improve the purity of the final product. Typical examples of endotoxin binding ligands include histamine, nitrogen-containing heterocyclic compounds, and polymyxin B. However, polymyxin B is known to induce production of interleukin-1, an exogenous pyrogen, and thus must be shown to be absent in the final product if used. Example of using anion exchange chromatography to purify albumin: 2% of the endotoxin does not bind to the column. However, this 2% washes out before the albumin peak, and can thus be removed simply by starting collection after this 2% has washed out. 10% of the endotoxin that does bind to the column (9.8% of the original total) will eventually wash out after the albumin peak. This can be prevented from entering the final product by stopping collection before this happens. The remaining 90% of the bound endotoxin (88.2% of the original total) must be cleaned off the column using NaOH An alternative to anion exchange is cation exchange chromatography, in which positively charged solutes bind to the solid chromatographic media. In this method, the target binds to the column instead of the endotoxin.
== Use in drug delivery and release == Radioligands are administered through four main routes: intravenously, subcutaneous injection, intraperitoneally, and orally. While intravenous application is the most used route of injection, the route is dependent on the mechanism of action and overall aim of the binding. Before application of the ligand, clinicians will perform imaging, generally via positron emission tomography (PET) or single-photon emission computed tomography (SPECT) for baseline comparison after radioligand administration. Once the radioligand is administered, the radioligand will travel to the target tissue and selectively bind. The structure of the compound allows clinicians to easily identify the path traveled and the destination via repeated imaging and the signal put out by the radiotracer attached to the ligand. Direct radiotherapy performed via ionizing radiation can cause tissue damage and hypoxia to tissues other than the target. While this effect is lessened in a target radiotracer therapy utilizing radioligands, there is still an impact on the surrounding tissue described as Radiation Induced Bystander Effect (RIBE). Surrounding cells altered by the radioligand and displaying RIBE can show signs of stress, chromosomal abnormalities, or even experience cell death. However, the type of radiation used, whether 𝜶, β, or both can have a dramatically different effect on both the target binding site and surrounding tissue.
Sources: en.wikipedia.org
Small copper carrier or SCC is a small molecule that transports copper in urine. It is excreted in the kidneys in humans or mice where the liver is unable to excrete excess copper in bile. This happens in Wilson's disease where the presence of copper in urine is a diagnostic. It was discovered by Lawrence Wilson Gray and Svetlana Lutsenko. The molecule is 2 kDa. Its exact nature is not yet known but is presumed to be a peptide. The same peptide also appears in blood and urine of many different mammals. Its copper free molecular weight is 1329.5. In neutral conditions the small copper carrier molecule has a negative charge. Copper is bound to the carrier via oxygen and nitrogen (O or N).
An estimated 90 percent of national Yemeni food consumption is dependent on imports, a factor that makes the country particularly vulnerable to trade disruptions, such as the one caused by the ongoing civil war. When trade flows were disrupted after 2015, this structural reliance rapidly translated into widespread food insecurity, with early UN assessments suggesting that two thirds of the population faced some degree of food shortage. Subsequent analyses describe a population increasingly reliant on food aid because of a combination of factors: the uncontrolled inflation, the prolonged suspension of many public-sector salaries, and the naval controls and port inspections imposed by the Saudi-led coalition, which slow and reduce imports through the main Red Sea ports, all are frequently cited as important factors to the economic stagnation. Between January and November 2020, the average cost of meeting food requirements was estimated to have risen by about 16 percent, making basic needs harder to afford even where these were still available. Humanitarian organisations and UN officials have repeatedly warned that all these dynamics are “starving” Yemen and have placed the country in a situation which the UN Secretary-General defined as the worst famine seen globally in decades.
=== Poisoning === In 1982, the US Mint began minting pennies coated in copper but containing primarily zinc. Zinc pennies pose a risk of zinc toxicosis, which can be fatal. One reported case of chronic ingestion of 425 pennies (over 1 kg of zinc) resulted in death due to gastrointestinal bacterial and fungal sepsis. Another patient who ingested 12 grams of zinc showed only lethargy and ataxia (gross lack of coordination of muscle movements). Several other cases have been reported of humans suffering zinc intoxication by the ingestion of zinc coins. Pennies and other small coins are sometimes ingested by dogs, requiring veterinary removal of the foreign objects. The zinc content of some coins can cause zinc toxicity, commonly fatal in dogs through severe hemolytic anemia and liver or kidney damage; vomiting and diarrhea are possible symptoms. Zinc is highly toxic in parrots and poisoning can often be fatal. The consumption of fruit juices stored in galvanized cans has resulted in mass parrot poisonings with zinc.
With the dissolution of the Soviet Union and the Fall of Communism, there was a split among Marxist–Leninists between those hardline Marxist–Leninists, sometimes referred to in the media as neo-Stalinists, which remained committed to orthodox Marxism–Leninism, and those democratic Marxist–Leninists which continued to work within the liberal-democratic process for a democratic road to socialism, while many other ruling Marxist–Leninist parties became closer to democratic socialist and social democratic parties. Outside Communist states, reformed Marxist–Leninist communist parties have led or been part of left-leaning coalitions, including in the former Eastern Bloc. In Nepal, Marxist–Leninists (CPN UML and Nepal Communist Party) were part of the 1st Nepalese Constituent Assembly, which abolished the monarchy in 2008 and turned the country into a federal liberal-democratic republic, and have democratically shared power with Maoists (CPN Maoist), social democrats (Nepali Congress), and others as part of their People's Multiparty Democracy.
Defender – 16 Half-back – 14 Midfielder – 49 Half-forward – 22 Forward – 19 Ruckman – 10 Utility – 3 The TAC Cup was the league with the highest number of players drafted, with forty-five in total. The Dandenong Stingrays in the TAC Cup had the most players drafted out of any team with seven players.
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.
它促进未成熟T细胞分化并增强成熟T细胞的增殖与细胞因子分泌。这些作用有助于放大抗原特异性免疫应答。