If you have been reading about RP-HPLC and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-09-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
Quantifying thymosin alpha-1 in a sample usually relies on reverse-phase high-performance liquid chromatography. The peptide lacks strong chromophores, so detection often occurs at 214 nm, where the peptide backbone absorbs. Mass spectrometry provides confirmatory identification and can detect sequence variants or truncations. Immunoassays have been used in biological matrices, but they may cross-react with related fragments. For purity assessment, chromatographic peak area gives the main component percentage, while mass accuracy verifies molecular identity.
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.
胸腺素α1（thymosin alpha 1，Tα1）是一种由28个氨基酸组成的酸性肽，N端被乙酰化，分子量约为3108道尔顿。该肽最早从牛胸腺组织提取物中分离，属于胸腺素组分5的一个成分。其序列在不同哺乳动物中高度保守，提示其具有基本的生物学功能。名称中的“α1”指其在电泳中的迁移位置，并非表示亚型编号。它既存在于胸腺，也存在于脾脏和淋巴结等免疫组织。
20世纪70年代，研究者从胸腺提取物中纯化出多种小肽，Tα1是其中被较早表征的一种。最初的制备依赖组织匀浆和层析步骤，产量低且成分复杂。随着固相肽合成技术成熟，实验室和工业界能够生产与天然序列一致的合成版本。合成肽的纯度可达95%以上，并可通过反相高效液相色谱和质谱进行鉴定。这一转变使研究不再依赖动物胸腺来源。
| Property | Value | Notes |
|---|---|---|
| Detection wavelength | 214 nm | Peptide bond absorption; 280 nm is not useful. |
| Confirmatory method | Electrospray mass spectrometry | Verifies mass near 3108 Da. |
| Solution stability | Limited at room temperature | Aqueous solutions degrade faster than powder. |
| Recommended storage | -20 °C | For lyophilized powder; protect from moisture. |
| Purity criterion | ≥95% by RP-HPLC | Typical research-grade specification. |
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography, which separates the peptide from closely related impurities and from truncated or oxidized variants. Mass spectrometry supplies the molecular mass and confirms the expected sequence length, while amino acid analysis can be used to check composition. Because the molecule has no chromophore beyond the peptide backbone, ultraviolet detection is typically performed at a low wavelength, where baseline interference from solvents and buffers is a practical concern. Water content and counter-ion content are often reported alongside purity.
Practical handling focuses on limiting adsorption and contamination. The peptide dissolves readily in water, and dilute solutions tend to adhere to plastic and glass surfaces, so an inert carrier protein or a defined buffer can reduce losses in laboratory work. Workers also record the counter-ion form, since an acetate or trifluoroacetate salt changes the mass balance of the weighed powder. Documentation of lot number, purity value, and storage history supports reproducibility when results from different laboratories are compared.
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.
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
On 19 March 2015, a group of leading biologists urged a worldwide ban on clinical use of methods, particularly the use of CRISPR and zinc finger, to edit the human genome in a way that can be inherited. In April 2015, Chinese researchers reported results of basic research to edit the DNA of non-viable human embryos using CRISPR.
==== Rebuilding links with the West ==== In 1999, Libya began secret talks with the British government to normalize relations. In 2001, Gaddafi publicly condemned the September 11 attacks on the US by al-Qaeda, expressing sympathy with the victims and calling for Libyan involvement in the US-led war on terror against militant Islamism. His government continued suppressing domestic Islamism, at the same time as Gaddafi called for the wider application of sharia law. Libya also cemented connections with China and North Korea, being visited by Chinese President Jiang Zemin in April 2002. However, relations with China became strained in May 2006 due to a visit to Tripoli by Taiwanese President Chen Shui-bian. Influenced by the events of the Iraq War, in December 2003, Libya renounced its possession of weapons of mass destruction, decommissioning its chemical and nuclear weapons programs. Relations with the US improved as a result. British Prime Minister Tony Blair visited Gaddafi in March 2004; the pair developed close personal ties. In 2003, Libya paid US$2.7 billion to the families of the victims of the Lockerbie bombing as it was the condition the US and UK had made for terminating the remaining UN sanctions. Libya continued to deny any role in the bombing. In 2009, Gaddafi attempted to strong-arm global energy companies operating in Libya to cover Libya's settlement with the families of the victims of Lockerbie.
=== Ha–He === James Haber (b. 1943). American molecular biologist at Brandeis University known for his discoveries in the field of DNA repair. Member Natl. Acad. Sci. USA. J. B. S. Haldane (John Burdon Sanderson Haldane, 1892–1964). British (and later Indian) geneticist, biochemist (study of enzymes) and statistician, at University College London and at the end of his life at the Indian Statistical Institute. Apart from his contributions to science, he was notable for political activism and wrote many articles for the Daily Worker. Gordon Hammes (b. 1934). American biochemist at Cornell and Duke University, noted for work on enzyme mechanisms and kinetics. Member Natl. Acad. Sci. USA. Philip Handler (1917–1981). American nutritionist and biochemist, noted for the understanding of nicotinic acid deficiency and the discovery of the tryptophan-nicotinic acid relationship. He was at Duke University until he became President of the Natl. Acad. Sci. USA Jean Hanson (1919–1973). British biophysicist and zoologist at Massachusetts Institute of Technology known for her contributions to muscle research. Arthur Harden FRS (1865–1940). British biochemist at the Lister Institute, known for work on the fermentation of sugar and fermentative enzymes. Nobel Prize in Chemistry (1929). Grahame Hardie FRS (b. 1950), British biochemist at the University of Dundee, known for work on AMP-activated protein kinase. Harry Harris FRS, FCRP (1919–1994), British-born biochemist who showed that human genetic variation was not rare. Edwin B.
Sources: en.wikipedia.org
==== Other actions ==== Tianeptine modestly enhances the mesolimbic release of dopamine and potentiates CNS D2 and D3 receptors. Tianeptine has no affinity for the dopamine transporter or the dopamine receptors. CREB-TF (CREB, cAMP response element-binding protein) is a cellular transcription factor. It binds to certain DNA sequences called cAMP response elements (CRE), thereby increasing or decreasing the transcription of the genes. CREB has a well-documented role in neuronal plasticity and long-term memory formation in the brain. Cocaine- and amphetamine-regulated transcript, also known as CART, is a neuropeptide protein that in humans is encoded by the CARTPT gene. CART appears to have roles in reward, feeding, stress, and it has the functional properties of an endogenous psychostimulant. Taking into account that CART production is upregulated by CREB, it could be hypothesized that due to tianeptine's central role in BDNF and neuronal plasticity, this CREB may be the transcription cascade through which this drug enhances mesolimbic release of dopamine. Research indicates possible anticonvulsant (anti-seizure) and analgesic (painkilling) activity of tianeptine via downstream modulation of adenosine A1 receptors (as the effects could be experimentally blocked by antagonists of this receptor). Tianpetine is also weak histone deacetylase (HDAC) inhibitor, specifically of HDAC1 and HDAC2 but not of HDAC3, and analogues with greatly increased potency such as tianeptinaline have been developed.
Both sides also agreed to establish communication channels for AI-related issues. The US welcomes the arrival of the pair of giant pandas loaned by China to the Atlanta Zoo. The two countries also agreed to sign a memorandum of understanding as soon as possible to strengthen crisis communication and prevention, and to continue to cooperate in the search for the remains of missing US military personnel in China. The US announced that the reduced tariffs on $30 billion of non-sensitive goods from each side would including agricultural goods, wood and cosmetics, as well as US imports such as small appliances, toys, decorations. The US also said China agreed to import 10 million tons of coals from the US in 2027 and 2028. Chinese foreign minister Wang Yi said that Xi's visit to the United States "further expanded the connotation of the new positioning of China–US relations", clearly defined respect, fairness and equality, and at the same time "provided clearer strategic guidance for China and the United States to explore the way of major powers getting along". He said that "It means the two countries have equal sovereignty and no one is more superior than the other. None is domineering or abusive and they should resolve their own concerns on an equal footing". Wang also said that Peng Liyuan and Melania Trump's interactions "brought the hearts of the two peoples closer" and that "Warm and personable first-lady diplomacy has injected a softer force into the visit".
== Timeline == After filing for bankruptcy, ownership of the hospital went up for bid, and there were two major corporations interested: Adventist Health with University of California San Francisco (UCSF) and American Advanced Management. During this time, a loan of 57 million dollars was approved for the reopening of the hospital from a state funded 300 million dollar bailout program for struggling hospitals in California. Ultimately, the bankruptcy court approved the bid from American Advanced Management in mid February 2024. The hospital has since been moving forward with rebuilding and upgrading, and CEO Steve Stark has goals to reopen by February 2025, given that they are able to fill the necessary positions.
== Adverse effects == The drug label (in some jurisdictions) has warnings with regard to the risk of respiratory depression, anticholinergic toxicity and opioid overdose, the risk of dehydration and electrolyte imbalance that people with severe diarrhea always run, and toxic megacolon in people with ulcerative colitis. Other adverse effects include numbness in the hands and feet, euphoria, depression, lethargy, confusion, drowsiness, dizziness, restlessness, headache, hallucinations, edema, hives, swollen gums, itchiness, vomiting, nausea, loss of appetite, and stomach pain.
Sources: en.wikipedia.org
Reverse-phase HPLC with ultraviolet detection at 214 nm is common. Mass spectrometry is used to confirm molecular identity and detect modifications. Immunoassays exist but may not distinguish the intact peptide from fragments.
The lyophilized powder is usually stored at -20 °C or below. Dissolved solutions are less stable and should be prepared fresh when possible. Freeze-thaw cycling can reduce integrity.
It lacks aromatic residues, so it does not absorb strongly at 280 nm. Its negative charge and hydrophilic nature can affect chromatographic retention. These properties require method development for reliable separation.
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。