The short version of RP-HPLC fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-20 and is reviewed periodically as new material appears.
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.
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。
市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
| 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. |
Lyophilized material is generally held at reduced temperature to slow degradation, and storage at minus twenty degrees Celsius or lower is common practice for long-term retention. Short-term working portions are often kept between two and eight degrees Celsius. Once dissolved, the peptide is less stable than the dry powder, and repeated freeze-thaw cycles are associated with loss of material and with aggregate formation. Vials are usually allowed to reach room temperature before opening so that condensation does not introduce moisture, and solutions are protected from light where practical.
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.
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.
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.
=== N05AH Diazepines, oxazepines, thiazepines and oxepines === N05AH01 Loxapine N05AH02 Clozapine N05AH03 Olanzapine N05AH04 Quetiapine N05AH05 Asenapine N05AH06 Clotiapine N05AH53 Olanzapine and samidorphan
=== Film and television === Six months prior to his graduation from Guildhall, McGregor began a leading role in Dennis Potter's six-part Channel 4 series Lipstick on Your Collar (1993). He then starred in the BBC adaptation of Scarlet and Black (also 1993) with Rachel Weisz and made his film debut in Bill Forsyth's Being Human (1994). For his role in the thriller Shallow Grave (also 1994), he won an Empire Award. The film was his first collaboration with director Danny Boyle. He had a major role in the 1996 Channel 4 comedy-drama film Brassed Off, written and directed by Mark Herman. His international breakthrough followed with the role of heroin addict Mark Renton in Boyle's Trainspotting (1996), an adaptation of Irvine Welsh's novel of the same name. In 1998, McGregor played the male romantic lead role in the British film Little Voice, and rockstar Curt Wild in the film Velvet Goldmine directed by Todd Haynes. He was cast as the young Obi-Wan Kenobi in the Star Wars prequel trilogy, released between 1999 and 2005. Kenobi was originally played by Alec Guinness in the first Star Wars trilogy. McGregor's uncle, Denis Lawson, had played Wedge Antilles in the original trilogy. While the prequels received mixed reviews, McGregor's performance was well received. McGregor said making the prequels was difficult, as he had to act mostly against green screens and the dialogue was "not exactly Shakespeare". He also stated that the negative reaction to the films had been difficult.
Wild non-Saccharomyces yeasts often need a much greater exposure to oxygen in order to build up survival factors which is why many of these yeasts are often found living oxidatively as "film yeast" on the surface of wines in tanks or barrels.
=== Use as psychoactive drugs === Preparations of plants and fungi containing alkaloids and their extracts, and later pure alkaloids, have long been used as psychoactive substances. Cocaine, caffeine, and cathinone are stimulants of the central nervous system. Mescaline and many indole alkaloids (such as psilocybin, dimethyltryptamine and ibogaine) have hallucinogenic effect. Morphine and codeine are strong narcotic pain killers. There are alkaloids that do not have strong psychoactive effect themselves, but are precursors for semi-synthetic psychoactive drugs. For example, ephedrine and pseudoephedrine are used to produce methcathinone and methamphetamine. Thebaine is used in the synthesis of many painkillers such as oxycodone.
Sources: en.wikipedia.org
On 14 August 1926, Oscar Tiegs married Ethel Mary Hamilton, a telephonist, at the Presbyterian Church in the Melbourne suburb of Hawthorn. Tiegs was known to form lasting friendships, even from relatively brief associations. For example, colleagues he met only once while on a trip to Europe in 1928, had fond memories of him. He was known as Sandy Tiegs to his friends and colleagues. He was godfather to David, the son of his mentor and colleague, Professor Brailsford Robertson. Tiegs was always interested in learning and research, and was known to find administration and committee work distasteful. This would appear to be at odds with his being a Councillor, and Chair of the Library Committee, for The Royal Society of Victoria. As head of the Melbourne University's Department of Zoology, he encouraged research and empowered his staff to set their own courses of activity with a directed freedom that nurtured world class research. He tended not to be interested in the research of others unless it was closely aligned with his own, yet was proud of his staff and was keen to show visitors what his staff were doing. He lectured without notes, mainly to first year students, to whom he gave a solid background in elementary zoology and comparative morphology, in a manner which was considered a model of presentation and clarity. He gave special lectures on arthropod evolution and the vertebrate nervous system to senior students.
Methylenetetrahydrofolate reductase (MTHFR) is the rate-limiting enzyme in the methyl cycle, and it is encoded by the MTHFR gene. Methylenetetrahydrofolate reductase catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a cosubstrate for homocysteine remethylation to methionine. Natural variation in this gene is common in otherwise healthy people. Although some variants have been reported to influence susceptibility to occlusive vascular disease, neural tube defects, Alzheimer's disease and other forms of dementia, colon cancer, and acute leukemia, findings from small early studies have not been reproduced. Some mutations in this gene are associated with methylenetetrahydrofolate reductase deficiency. Complex I deficiency with recessive spastic paraparesis has also been linked to MTHFR variants. In addition, the aberrant promoter hypermethylation of this gene is associated with male infertility and recurrent spontaneous abortion.
There is no way of detecting multiple substitutions at a single site, thus the estimate of the number of substitutions is always an underestimate. In addition, in the example above two non-synonymous and one synonymous substitution occurred at the third site; however, because substitutions restored the original sequence, there is no evidence of any substitution. As the divergence time between two sequences increases, so too does the amount of multiple substitutions. Thus "long branches" in a dN/dS analysis can lead to underestimates of both dN and dS, and the longer the branch, the harder it is to correct for the introduced noise. Of course, the ancestral sequence is usually unknown, and two lineages being compared will have been evolving in parallel since their last common ancestor. This effect can be mitigated by constructing the ancestral sequence; the accuracy of this sequence is enhanced by having a large number of sequences descended from that common ancestor to constrain its sequence by phylogenetic methods. Methods that account for biases in codon usage and transition/transversion rates are substantially more reliable than those that do not.
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。