BDNF expression comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-09-01. Numbers and descriptions here follow the published literature rather than marketing material.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
== Personal life == Liebling has made dubious claims that he turned to drug dealing during the 1970s, smuggling substances for the Medellin Cartel through Virginia and Colombia during the height of the Pablo Escobar era. He went as far as to claim he earned "tens of millions - sometimes in cash" during this period, but "blew it all, every dime of it on [his] own personal whoring, car-buying, house-buying for [his] friends, buying Ferraris and chinchilla coats and diamond rings for broads and flaunting it." In the 1980s, Liebling was in a relationship with Cheri Blade, a member of the band Chained Lace, with whom Pentagram often toured. He married Hallie Liebling on November 25, 2009. The couple welcomed their son, Robert Joseph Liebling, in 2010, when Hallie was 24 years old. They have been separated since around 2013.
== Horticultural uses == The international registration authority for the genus is the American Violet Society, where growers register new Viola cultivars. A coding system is used for cultivar description of ten horticultural divisions, such as Violet (Vt) and Violetta (Vtta). Examples include Viola 'Little David' (Vtta) and Viola 'Königin Charlotte' (Vt). In this system violets (Vt) are defined as "stoloniferous perennials with small, highly fragrant, self-coloured purple, blue or white flowers in late winter and early spring".
In this method, DNA molecules and primers are first attached on a slide or flow cell and amplified with polymerase so that local clonal DNA colonies, later coined "DNA clusters", are formed. To determine the sequence, four types of reversible terminator bases (RT-bases) are added and non-incorporated nucleotides are washed away. A camera takes images of the fluorescently labeled nucleotides. Then the dye, along with the terminal 3' blocker, is chemically removed from the DNA, allowing for the next cycle to begin. Unlike pyrosequencing, the DNA chains are extended one nucleotide at a time and image acquisition can be performed at a delayed moment, allowing for very large arrays of DNA colonies to be captured by sequential images taken from a single camera.
Sources: en.wikipedia.org
Tim Hortons, currently owned by Restaurant Brands International, opened its first store on May 17, 1964, in Hamilton, Ontario. It is the fourth largest publicly traded quick-service restaurant chain in North America based on market capitalization, and the largest in Canada. It has cornered the Canadian market for baked goods (76%) and coffee (62% compared to Starbucks, in the number two position, at 7%). The company has experienced substantial growth in the United States, where it has 613 stores (April 2011, about 220 more than it had in June 2008). It has a same-store sales growth rate of 3.9% in Canada and 4.9% in the US. The new partnership with Cold Stone Creamery helped push its US presence to over 600 stores. The partnership has since dissolved. Sales exceeded $2 billion in 2008. It was controlled by Wendy's International Inc. for 11 of the 46 years of operation, from August 8, 1995, until the end of 2006. On April 3, 2011, Tim Hortons oversaw 3,782 locations in North America 3,169 of which were in Canada. In the fourth quarter of 2010 Tim Hortons' profits were 27% more than they were over the entire 2009 fiscal year (for the quarter net income was up 314%). In Forbes' 2011 edition of the world's 2000 largest companies, Tim Hortons placed 1469th overall (up from 1714th in 2010) with annual sales of $2.6 billion (up from $2.014 billion in 2010), profits totalling $628 million (up from $280 million), assets worth $2.5 billion (up from $1.90 billion) and a market value of $7.5 billion (up from $5.41 billion).
== Clothing and associated items == When Lindow Man was discovered in 1984 at Lindow Moss in Cheshire, England, he was wearing only a fox-fur band around his left arm. Remains of this armband survived attached to his body. A twisted cord made from animal sinew, the tough tissue that connects muscle to bone, was also found around his neck. According to the British Museum, the cord may have been used as a garrotte to strangle him, although it could instead have been worn as a necklace.
== External links == The Miller–Urey experiment website, a simulation of the Miller–Urey Experiment along with a video interview with Stanley Miller] by Scott Ellis from CalSpace (UCSD) Origin-Of-Life Chemistry Revisited: Reanalysis of famous spark-discharge experiments reveals a richer collection of amino acids were formed. Miller–Urey experiment explained Miller experiment with Lego bricks "Stanley Miller's Experiment: Sparking the Building Blocks of Life" on PBS Cairns-Smith, A.G. (1966). "The origin of life and the nature of the primitive gene". Journal of Theoretical Biology. 10 (1): 53–88. Bibcode:1966JThBi..10...53C. doi:10.1016/0022-5193(66)90178-0. PMID 5964688. Details of 2008 re-analysis
In the summer of 1645, Royalist forces were defeated by the New Model Army at the Battle of Langport, in Somerset. Following further victories at Bridgwater and Sherborne, Sir Thomas Fairfax marched on Bristol. Prince Rupert returned to organise the defence of the city. The Parliamentary forces besieged the city and after three weeks attacked, eventually forcing Rupert to surrender on 10 September. The First Civil War ended the following year. There were no further military actions in Bristol during the second and third civil wars. In 1656, Oliver Cromwell ordered the destruction of the castle.
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.