lyophilized powder is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-08-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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。
Lyophilized thymosin alpha 1 is typically stored refrigerated at 2 to 8 degrees Celsius and kept away from light. Reconstituted solutions are less stable and are usually used promptly after preparation. Repeated freeze-thaw cycles are avoided because they can promote aggregation and loss of activity. The peptide adsorbs to some plastic and glass surfaces, so a carrier protein is often added to dilute working solutions. Manufacturer instructions and published protocols both govern handling.
Identity and purity testing for thymosin alpha 1 relies mainly on reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatography separates the parent peptide from truncated or modified variants, while mass spectrometry confirms the expected molecular mass. Amino acid analysis and peptide mapping provide additional sequence confirmation. Counterion content, water content, and residual solvents are measured separately as part of specification testing. No single method captures every attribute, so laboratories combine several techniques.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
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.
Thymosin alpha-1 is supplied as a lyophilized powder in most research settings. The solid dissolves readily in water and in common aqueous buffers, and it is typically reconstituted shortly before use. Solutions are clear and colourless at ordinary working concentrations. Because the peptide is hygroscopic, weighing and reconstitution are usually performed with minimal exposure to ambient air. Aliquots are prepared to avoid repeated freeze-thaw cycles, and working solutions are kept cold.
Long-term storage is generally at minus twenty degrees Celsius or colder, preferably desiccated and protected from light. Lyophilized material is more stable than reconstituted solution, which degrades faster at room temperature. Stability depends on pH, ionic strength, and the presence of oxidising agents. Published stability data for the peptide are limited, so storage claims in catalogues should be treated as general guidance rather than measured guarantees. Freeze-thaw cycles are kept to a minimum.
== Structure of the compound == The pyrithione ligands, which are formally monoanions, are chelated to Zn2+ via oxygen and sulfur centers. In the crystalline state, zinc pyrithione exists as a centrosymmetric dimer (see figure), where each zinc is bonded to two sulfur and three oxygen centers. In solution, however, the dimers dissociate via scission of one Zn-O bond. This compound was first described in the 1930s. Pyrithione is the conjugate base derived from 2-mercaptopyridine-N-oxide (CAS# 1121-31-9), a derivative of pyridine-N-oxide.
=== 1979 === January 1: The United States and China normalize diplomatic relations. January 7: Vietnam deposes the Khmer Rouge and installs a pro-Vietnam, pro-Soviet government known as the People's Republic of Kampuchea. January 16: The Iranian Revolution ousts the pro-Western Shah, Mohammed Reza Pahlavi, and installs a theocracy under Grand Ayatollah Ruhollah Khomeini. The Central Treaty Organization dissolves as a result. February 17: Sino-Vietnamese War, China launches a punitive attack on Vietnam to punish it for invading Cambodia February 22: Saint Lucia becomes independent from the UK. February 24: A war broke out between Yemen Arab Republic and South Yemen. May 4: Margaret Thatcher is elected Prime Minister of the United Kingdom, becoming the first female to lead a major Western democracy. May 9: Civil war breaks out in El Salvador between Marxist-led insurgents and the U.S.-backed government. June 2: Pope John Paul II begins his first pastoral visit to his native Poland. June 18: U.S. President Jimmy Carter and Soviet leader Leonid Brezhnev sign the SALT II agreement, outlining limitations and guidelines for nuclear weapons. July 3: President Carter signs the first directive for financial aid to opponents of the pro-Soviet regime in Kabul, Afghanistan. July 16: Saddam Hussein becomes President of Iraq after Ahmed Hassan al-Bakr steps down. July 17: Marxist-led Sandinista revolutionaries overthrow the U.S.-backed Somoza dictatorship in Nicaragua. The Contra insurgency begins shortly thereafter.
Several times during the 1970s and 1980s, Detroit was named the "arson capital of America", and the city was also repeatedly dubbed the "murder capital of America". Detroit was frequently listed by FBI crime statistics as the "most dangerous city in America" during this time frame. Crime rates in Detroit peaked in 1991 at more than 2,700 violent crimes per 100,000 people. Population decline left abandoned buildings behind that became magnets for the drug trade, arson, and other criminal activity. The city's criminality has pushed tourism away from the city, and several foreign countries even issued travel warnings for the city. Around this period, in the days of the year preceding and including Halloween, Detroit citizens went on a rampage called "Devil's Night". A tradition of light-hearted minor vandalism, such as soaping windows, had emerged in the 1930s, but by the 1980s, it had become, said Mayor Young, "a vision from hell." During the height of the drug era, Detroit residents routinely set fire to houses that were known as popular drug-dealing locations, accusing the city's police of being either unwilling or unable to solve the deep problems of the city. The arson primarily occurred in the inner city, but surrounding suburbs were also often affected. The crimes became increasingly destructive throughout this period. Over 800 fires were set, mostly to vacant houses, in the peak year of 1984, overwhelming the city's fire department.
Sources: en.wikipedia.org
== Interactions == Phenibut may mutually potentiate and extend the duration of the effects of other CNS depressants, including anxiolytics, antipsychotics, sedatives, opioids, anticonvulsants, and alcohol.
== Side effects == Amphotericin B is well known for its severe and potentially lethal side effects, earning it the nickname "amphoterrible". Very often, it causes a serious reaction soon after infusion (within 1 to 3 hours), consisting of high fever, shaking chills, hypotension, anorexia, nausea, vomiting, headache, dyspnea and tachypnea, drowsiness, and generalized weakness. The violent chills and fevers have caused the drug to be nicknamed "shake and bake". The precise etiology of the reaction is unclear, although it may involve increased prostaglandin synthesis and the release of cytokines from macrophages. Deoxycholate formulations (ABD) may also stimulate the release of histamine from mast cells and basophils. Reactions sometimes subside with later applications of the drug. This nearly universal febrile response necessitates a critical (and diagnostically difficult) professional determination as to whether the onset of high fever is a novel symptom of a fast-progressing disease or merely the effect of the drug. To decrease the likelihood and severity of the symptoms, initial doses should be low and increased slowly. Paracetamol, pethidine, diphenhydramine, and hydrocortisone have all been used to treat or prevent the syndrome, but the prophylactic use of these drugs is often limited by the patient's condition. Intravenously administered amphotericin B in therapeutic doses has also been associated with multiple organ damage. Kidney damage, including Type I (distal) renal tubular acidosis, is a frequently reported side effect, and can be severe and/or irreversible.
In their first major declaration on the issue since 2016, global leaders also committed to raising $100 million to update and implement AMR action plans. However, the final draft of the declaration omitted an earlier target to reduce antibiotic use in animals by 30% by 2030, due to opposition from meat-producing countries and the farming industry. Critics argue this omission is a major weakness, as livestock accounts for around 73% of global sales of antimicrobial agents, including antibiotics, antivirals, and antiparasitics.
Sources: en.wikipedia.org
== Services == Americold provides temperature-controlled warehousing along with consolidation and multi-vendor consolidation transportation programs. Value added services complement typical warehousing and distribution services and include blast freezing, pick and pack, labeling/relabeling, repacking, kitting, staging, cross-dock, sloughing/tempering, plus light assembly and food processing services. Americold owns and operates over 245 temperature-controlled warehouses, with more than 1 billion cubic feet of storage, in the United States, Australia, New Zealand, China, Argentina, and Canada. Americold's warehouses are a part of the supply chain connecting food producers, processors, distributors, and retailers to consumers.
=== Moisture content of wood in service === Wood retains its hygroscopic characteristics after it is put into use. It is then subjected to fluctuating humidity, the dominant factor in determining its EMC. These fluctuations may be more or less cyclical, such as diurnal changes or annual seasonal changes. To minimize the changes in wood moisture content or the movement of wooden objects in service, wood is usually dried to a moisture content that is close to the average EMC conditions to which it will be exposed. These conditions vary for interior uses compared with exterior uses in a given geographic location. For example, according to the Australian Standard for Timber Drying Quality (AS/NZS 4787, 2001), the EMC is recommended to be 10–12% for the majority of Australian states, although extreme cases are up to 15 to 18% for some places in Queensland, Northern Territory, Western Australia and Tasmania. However, the EMC is as low as 6 to 7% in dry centrally heated houses and offices or in permanently air-conditioned buildings.
The amount of UV radiation produced by the Sun means that the Earth would not be able to sustain life on dry land if most of that light were not filtered out by the atmosphere. UV light from the Sun at wavelengths shorter than approximately 300 nm is absorbed in the atmosphere, primarily by ozone and molecular oxygen, before it reaches the ground. However, UV (specifically, UVB) is also responsible for the formation of vitamin D in most land vertebrates, including humans. The UV spectrum, thus, has effects both beneficial and detrimental to life. The lower wavelength limit of the visible spectrum is conventionally taken as 400 nm. Although ultraviolet rays are not generally visible to humans, 400 nm is not a sharp cutoff, with shorter and shorter wavelengths becoming less and less visible in this range. Insects, birds, and some mammals can see near-UV (NUV), because they can see somewhat shorter wavelengths than what humans can see.
Sources: en.wikipedia.org
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。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
The lyophilized powder is kept refrigerated at 2 to 8 degrees Celsius and protected from light. Reconstituted solutions should be used promptly. Freezing and thawing repeatedly is avoided.