Lyophilized powder raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-08-05 and is reviewed periodically as new material appears.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
== Medical uses == Seven controlled efficacy trials were conducted of vilazodone for treatment of major depressive disorder. Five of these trials showed no significant influence of vilazodone over placebo on depressive symptoms. In the remaining two trials, small but significant advantages of vilazodone over placebo were found. According to these two eight-week trials in adults, vilazodone has an antidepressant response after one week of treatment. After eight weeks it resulted in a 13% greater response than placebo. Remission rates, however, were not significantly different versus placebo. According to the US Food and Drug Administration (FDA) in 2011, "it is unknown whether vilazodone has any advantages compared to other drugs in the antidepressant class." A 2019 review stated that "present studies do not suggest the superiority of vilazodone compared with other antidepressants." Development of vilazodone for generalized anxiety disorder has been stopped as of 2017. While there is tentative evidence of a small benefit in generalized anxiety disorder, there is a high rate of side effects.
=== Volatile compounds === Volatile compounds of green coffee beans include short-chain fatty acids, aldehydes, and nitrogen-containing aromatic molecules, such as derivatives of pyrazines (green-herbaceous-earthy odor). When green coffee beans are roasted, other molecules with the typical pleasant aroma of coffee are generated, which are not present in fresh green coffee. During roasting, the major part of the unpleasant-tasting volatile compounds are neutralized.
==== Benzamides ==== Amisulpride (Socian) ‡ – Selective dopamine antagonist. Higher doses (greater than 400 mg) act upon post-synaptic dopamine receptors resulting in a reduction in the positive symptoms of schizophrenia, such as psychosis. Lower doses, however, act upon dopamine autoreceptors, resulting in increased dopamine transmission, improving the negative symptoms of schizophrenia. Lower doses of amisulpride have also been shown to have antidepressant and anxiolytic effects in non-schizophrenic patients, leading to its use in dysthymia and social phobias. Nemonapride † – Used in Japan. Remoxipride # – Has a risk of causing aplastic anaemia and, hence, has been withdrawn from the market worldwide. It has also been found to possess relatively low (virtually absent) potential to induce hyperprolactinaemia and extrapyramidal symptoms, likely attributable to its comparatively weak binding to (and, hence, rapid dissociation from) the D2 receptor. Sultopride – An atypical antipsychotic of the benzamide chemical class used in Europe, Japan, and Hong Kong for the treatment of schizophrenia. It was launched by Sanofi-Aventis in 1976. Sultopride acts as a selective D2 and D3 receptor antagonist.
Sources: en.wikipedia.org
== Mechanism == Non-enzymatic malonylation occurs spontaneously through direct transfer of a malonyl group from malonyl‑CoA to the ε-amino group (–NH2) of a deprotonated lysine residue, without enzyme involvement. Only the deprotonated lysine residue can react in this way because its ε-amino group carries a free electron pair that can attack the carbonyl carbon of the highly reactive malonyl-CoA thioester, whose electron-withdrawing carboxyl group further increases its reactivity. Since the lysine residue has a pKa of about 10.5, however, it exists almost entirely in its protonated form at physiological pH (~7.4), with less than 0.1% deprotonated as calculated from the Henderson–Hasselbalch equation. Local protein microenvironments, such as near negatively charged residues or within hydrophobic pockets, can additionally enable lysine deprotonation, while broader conditions such as the more alkaline pH (~8.0) of the mitochondrial matrix increase the fraction of deprotonated lysine residues to about 0.3%, thereby favoring non-enzymatic malonylation. In compartments with near-neutral pH (~7.2), such as the cytosol or nucleus, lysine residues are therefore almost fully protonated and rely more on enzymatic malonylation there, suggesting that both mechanisms contribute to the overall malonylation pattern in cells. In enzymatic malonylation, protonated lysine residues (–NH3+), which is the form in which they almost all exist (≈ 99.9%) at physiological pH (~7.4), can also be modified.
=== Counterfeiting === In major re-export hubs like Singapore, Malaysia and Hong Kong, fish maw is frequently mislabeled as more expensive varieties of fish, due to high profit incentive and the high level of visual similarity between disparately priced species. HK Magazine in 2007 described two incidents of counterfeit fish maw in Hong Kong: one of dried rabbit ear, and the other of shoe rubber.
The process continued until 1817, when Sertürner published his results after thirteen years of research and a nearly disastrous trial on himself and three boys. The great advantage of purified morphine was that a patient could be treated with a known dose—whereas with raw plant material, as Gabriel Fallopius once lamented: "if soporifics are weak they do not help; if they are strong they are exceedingly dangerous". Morphine was the first pharmaceutical isolated from a natural product, and this success encouraged the isolation of other alkaloids: by 1820, isolations of noscapine, strychnine, veratrine, colchicine, caffeine, and quinine were reported. Morphine sales began in 1827, by Heinrich Emanuel Merck of Darmstadt, and helped him expand his family pharmacy into the Merck KGaA pharmaceutical company. Codeine was isolated in 1832 by Pierre Jean Robiquet. The use of diethyl ether and chloroform for general anesthesia began in 1846–1847, and rapidly displaced the use of opiates and tropane alkaloids from Solanaceae due to their relative safety. Heroin, the first semi-synthetic opioid, was first synthesized in 1874, but was not pursued until its rediscovery in 1897 by Felix Hoffmann at the Bayer pharmaceutical company in Elberfeld, Germany. From 1898 to 1910 heroin was marketed as a non-addictive morphine substitute and cough medicine for children. Because the lethal dose of heroin was viewed as a hundred times greater than its effective dose, heroin was advertised as a safer alternative to other opioids.
Sources: en.wikipedia.org
For several years after World War II, the United States developed and maintained a strategic force based on the Convair B-36 bomber that would be able to attack any potential enemy from bomber bases in the United States. It deployed atomic bombs around the world for potential use in conflicts. Over a period of a few years, many in the American defense community became increasingly convinced of the invincibility of the United States to a nuclear attack. Indeed, it became generally believed that the threat of nuclear war would deter any strike against the United States. Many proposals were suggested to put all American nuclear weapons under international control (by the newly formed United Nations, for example) as an effort to deter both their usage and a nuclear arms race. However, no terms could be arrived at that would be agreed upon by both the United States and the Soviet Union.
== Medical uses == In the US, galcanezumab is indicated in adults for the preventive treatment of migraine; and for the treatment of episodic cluster headache. In the EU, galcanezumab is indicated for the prophylaxis of migraine in adults who have at least four migraine days per month.
Under appropriate conditions, an addition reaction can occur between serine or cysteine residues of the target protein and the nitrile group to form imidic acid esters or thioimidates. This mechanism applies to the dipeptidyl peptidase 4 inhibitor vildagliptin used in diabetes mellitus, as well as to saxagliptin. The antibacterial antibiotic cefmetazole also acts as a covalent inhibitor, in this case targeting a bacterial peptidase. The calcium sensitizer levosimendan is presumed to react with the cardiac troponin protein complex. Such a reactive functional group is also referred to as a warhead. In certain cases, nitrile groups exert their effect primarily through steric interactions (i.e., spatial complementarity) by forming van der Waals forces with amino acid residues. This applies to the tyrosine kinase inhibitor bosutinib, which is used in chronic myeloid leukemia. Crystal structures have been reported in which bosutinib is complexed with various tyrosine kinases. Inhibitors of reverse transcriptase, such as Etravirin and Rilpivirin, are used in combination therapies against HIV. The acrylonitrile substructure of rilpivirine penetrates an aromatic cage composed of tyrosine, phenylalanine, and tryptophan, as demonstrated by the corresponding three-dimensional structure published in 2008. The serotonin reuptake inhibitor citalopram, used in the treatment of depression, was the most frequently prescribed psychotropic drug in Germany in 2016, with 290 million defined daily doses.
== Diagnosis == Substance use disorders can be confused with other psychiatric disorders. There are diagnoses for substance-induced mood disorders and substance-induced anxiety disorders and thus such overlap can be complicated. For this reason, the DSM-IV advises that diagnoses of primary psychiatric disorders not be made in the absence of sobriety (of a duration sufficient to allow for any substance-induced post-acute-withdrawal symptoms to dissipate) up to 1 year.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.