This is a working overview of 胸腺素α1, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-07-02 and is reviewed periodically as new material appears.
Laboratory work indicates that the peptide acts on cells of both the innate and adaptive immune systems. Reported effects include signalling through Toll-like receptors on dendritic cells, enhanced T-cell maturation, and increased natural killer cell activity. These actions are described largely from cell-culture and animal experiments, and the precise receptor-level events remain incompletely defined. Studies in humans have generally measured immune markers rather than a single defined molecular target. The resulting picture remains partly descriptive.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Results across trials have been mixed, and several studies were small or conducted under differing protocols. Regulatory status varies by country, and the compound is not approved in every jurisdiction where it is studied. Evidence for any single indication should be read with attention to sample size and endpoint choice.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Peptide | 28 amino acid residues |
| Molecular weight | Approximately 3108 Da | Depends on acetylation state |
| N-terminal modification | Acetylated | Affects charge and stability |
| Natural source | Fragment of thymosin beta-4 | Cleaved in vivo |
| Sequence length | 28 residues | Synthetic form matches natural |
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.
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。
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Yeasts, like all fungi, may have asexual and sexual reproductive cycles. The most common mode of vegetative growth in yeast is asexual reproduction by budding, where a small bud (also known as a bleb or daughter cell) is formed on the parent cell. The nucleus of the parent cell splits, producing a daughter nucleus that migrates into the daughter cell. The bud then continues to grow until it separates from the parent cell, forming a new cell. The daughter cell produced during the budding process is generally smaller than the mother cell. Some yeasts, including Schizosaccharomyces pombe, reproduce by fission instead of budding, and thereby creating two identically sized daughter cells. In general, under high-stress conditions such as nutrient starvation, haploid cells will die; under the same conditions, however, diploid cells can undergo sporulation, entering sexual reproduction (meiosis) and producing a variety of haploid spores, which can go on to mate (conjugate), reforming the diploid. The haploid fission yeast Schizosaccharomyces pombe is a facultative sexual microorganism that can undergo mating when nutrients are limited. Exposure of S. pombe to hydrogen peroxide, an agent that causes oxidative stress leading to oxidative DNA damage, strongly induces mating and the formation of meiotic spores. The budding yeast Saccharomyces cerevisiae reproduces by mitosis as diploid cells when nutrients are abundant, but when starved, this yeast undergoes meiosis to form haploid spores. Haploid cells may then reproduce asexually by mitosis. Katz Ezov et al.
∗The findings are a comparison between e-cigarette daily usage and the regulatory limits of chronic Permissible Daily Exposure from inhalation medications outlined by the US Pharmacopeia for cadmium, chromium, copper, lead and nickel, the Minimal Risk Level outlined by the Agency for Toxic Substances and Disease Registry for manganese and the Recommended Exposure Limit outlined by the National Institute for Occupational Safety and Health for aluminum, barium, iron, tin, titanium, zinc and zirconium, referring to a daily inhalation volume of 20 m3 air and a 10-h volume of 8.3 m3; values are in μg.
desynapsis The failure of homologous chromosomes that have synapsed normally during pachynema to remain paired during diplonema. Desynapsis is usually caused by the improper formation of chiasmata. Contrast asynapsis.
If a mutation is present in a germ cell, it can give rise to offspring that carries the mutation in all of its cells. This is the case in hereditary diseases. In particular, if there is a mutation in a DNA repair gene within a germ cell, humans carrying such germline mutations may have an increased risk of cancer. A list of 34 such germline mutations is given in the article DNA repair-deficiency disorder. An example of one is albinism, a mutation that occurs in the OCA1 or OCA2 gene. Individuals with this disorder are more prone to many types of cancers, other disorders and have impaired vision. DNA damage can cause an error when the DNA is replicated, and this error of replication can cause a gene mutation that, in turn, could cause a genetic disorder. DNA damages are repaired by the DNA repair system of the cell. Each cell has a number of pathways through which enzymes recognize and repair damages in DNA. Because DNA can be damaged in many ways, the process of DNA repair is an important way in which the body protects itself from disease. Once DNA damage has given rise to a mutation, the mutation cannot be repaired.
== Applications == One of the largest volume uses for ICP-MS is in the medical and forensic field, specifically, toxicology. A physician may order a metal assay for a number of reasons, such as suspicion of heavy metal poisoning, metabolic concerns, and even hepatological issues. Depending on the specific parameters unique to each patient's diagnostic plan, samples collected for analysis can range from whole blood, urine, plasma, serum, to even packed red blood cells. Another primary use for this instrument lies in the environmental field. Such applications include water testing for municipalities or private individuals all the way to soil, water and other material analysis for industrial purposes. In recent years, industrial and biological monitoring has presented another major need for metal analysis via ICP-MS. Individuals working in factories where exposure to metals is likely and unavoidable, such as a battery factory, are required by their employer to have their blood or urine analyzed for metal toxicity on a regular basis. This monitoring has become a mandatory practice implemented by the U.S. Occupational Safety and Health Administration, in an effort to protect workers from their work environment and ensure proper rotation of work duties (i.e. rotating employees from a high exposure position to a low exposure position). ICP-MS is also used widely in the geochemistry field for radiometric dating, in which it is used to analyze relative abundance of different isotopes, in particular uranium and lead.
Sources: en.wikipedia.org
In comparison, fetal haptic glucagon receptors are lowered in comparison to adult cells and the glycemic effect of glucagon is blunted. This temporary physiological change aids the increased rate of fetal development during the final trimester. Poorly managed maternal diabetes mellitus is linked to fetal macrosomia, increased risk of miscarriage, and defects in fetal development. Maternal hyperglycemia is also linked to increased insulin levels and beta cell hyperplasia in the post-term infant. Children of diabetic mothers are at an increased risk for conditions such as: polycythemia, renal vein thrombosis, hypocalcemia, respiratory distress syndrome, jaundice, cardiomyopathy, congenital heart disease, and improper organ development.
== History of space medicine and drug delivery == Concerns about aviation drug delivery started as early as 1924 when orthostatic stress was found to be the reason for a pilot's inability to digest chocolate during a flight. In addition, studies on the effect of digitalis on altitude were performed on both pigeons and cats in 1924, concluding that increased altitudes significantly increase the effects of digitalis on their systems, leading to a recommendation to decrease the dosage of digitalis in high altitudes to be two-fifths of the current dose. As outer space expeditions grew in the mid-twentieth century, missions established medical practices to deliver medicines for astronauts in missions. Project Apollo in the late 1960s to early 1970s began the use of using medicine bags, which came with commonly used drugs for motion sickness and pain relief in oral form (tablets and capsules) as well as a nasal spray. The Mercury Project was one of the first space expeditions to take medicine delivery to outer space. Injector systems were first developed and used then to deliver and inject drugs directly into an individual's spacesuit into their thighs. These injection tubes were used to deliver Tigan and Demerol, respectively, motion sickness and pain relief drugs. Studies in the 1980s examined common orally-delivered drug functionalities in altered space environments, beginning with acetaminophen, concluding that they were less effective in outer space.
Ninhydrin (2,2-dihydroxyindane-1,3-dione) is an organic compound with the formula C6H4(CO)2C(OH)2. It is used to detect ammonia and amines. Upon reaction with these amines, ninhydrin gets converted into deep blue or purple derivatives, which are called Ruhemann's purple. Ninhydrin is most commonly used to detect fingerprints in forensic cases, as the terminal amines of lysine residues in peptides and proteins sloughed off in fingerprints react with ninhydrin. Ninhydrin is a white solid that is soluble in ethanol and acetone. Ninhydrin can be considered as the hydrate of indane-1,2,3-trione.
Erowid.org – PCP Information National Institute of Drug Abuse InfoFacts: PCP (Phencyclidine) Archived 2012-01-06 at the Wayback Machine Drugs and Human Performance Fact Sheets on Phencyclidine Phencyclidine and Ketamine: A View From the Street-1981 article on the use and effects of PCP; Archived 2019-01-21 at the Wayback Machine "Phencyclidine". Drug Information Portal. U.S. National Library of Medicine. Archived from the original on May 7, 2021.
Sources: en.wikipedia.org
21st International Symposium on Chirality STEREOISOMERISM - OPTICAL ISOMERISM Symposium highlights-Session 5: New technologies for small molecule synthesis IUPAC nomenclature for amino acid configurations. Michigan State University's explanation of R/S nomenclature Chirality & Odour Perception at leffingwell.com Chirality & Bioactivity I.: Pharmacology Chirality and the Search for Extraterrestrial Life "The Handedness of the Universe" by Roger A Hegstrom and Dilip K Kondepudi, Scientific American, January 1990
Certain crystals alter the polarization plane of transmitted light, and when rotated between crossed polarizers, they alternate between bright and dark every 90°. The extinction angle is the angle between a specific crystal axis and the filter's polarization plane when the crystal appears dark (in extinction). For instance, this method can be employed to distinguish between perlatolic acid and imbricaric acid, which both form long, straight crystals in the GE solvent system but exhibit extinction angles of 0° and 45°, respectively, in relation to their long axis.
Ariel Steinberg (born 26 August 1992 in Mildura, Victoria, Australia) is an Australian rules footballer who played for the Essendon Football Club in the Australian Football League (AFL). He made his senior debut against West Coast in round 21 of the 2014 season.
Sources: en.wikipedia.org
It corresponds to the first 28 amino acids of thymosin beta-4, a larger protein found in many tissues. The fragment is acetylated at its N-terminus and is produced synthetically for research and pharmaceutical use. Synthetic and natural forms share the same sequence.
It is usually described as an immunomodulatory peptide rather than a classical hormone. It does not travel to a single distant organ in the manner of an endocrine hormone. Classification varies across sources, and some texts group it with thymic peptides generally.
The broad outline involves immune cell activation, but the specific molecular steps remain under investigation. Different studies report effects on dendritic cells, T cells, and natural killer cells. No single receptor has been confirmed as the sole mediator.
It is a chain of 28 amino acids, with an acetyl group attached to the first serine residue. The synthetic version replicates this sequence. Its molecular mass is about 3,108 daltons.