Everything below concerns Neurotrophic signalling. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-29. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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.
Defending against a full Russian or Chinese attack would require hundreds of thousands of satellites," according to MIT physicists Lisbeth Gronlund and David Wright. The cost of launching satellites is expected to decrease when the heavy-lift SpaceX Starship launch vehicle enters service. Still, the extreme expense of creating such a constellation—and replacing satellites as their orbits decay—has led the U.S. military to also pursue space-based midcourse options that would require fewer satellites. But these would be more expensive and no better than ground-based interceptors at telling decoys from warheads. Space-based interceptors would be guided by the nascent Hypersonic and Ballistic Tracking Space Sensor system, one of the tracking elements of the Space Development Agency's (SDA) seven-layer Proliferated Warfighter Space Architecture (PWSA). The Golden Dome would also be aimed at detecting and countering strikes delivered from a fractional orbital bombardment system (FOBS). Pentagon leaders have said the system could be used to put offensive weapons in space, giving a global strike capability that would create offensive overmatch. Defense Secretary Pete Hegseth has said the U.S. "will be able to strike anywhere, anytime". Satellites might carry the bunker-busting Common-Hypersonic Glide Body (C-HGB), which can reportedly fly 1,000 miles to strike within 14 inches of its target. The missile was designed to fit the HIMARS ground launcher, so several can be compactly racked in a satellite payload bays.
== Chemical properties == At physiological pH, the ε-amino group (–NH2) of the lysine residue exists almost entirely in its protonated form (–NH3+), whereas the carboxyl group (–COOH) of the malonyl group exists almost entirely in its deprotonated form (–COO-). Through the covalent attachment of a malonyl group to the ε-amino group, the lysine residue loses its positive charge and assumes the negative charge of the malonyl group, resulting in a charge shift from +1 to −1. This complete reversal of charge is thought to disrupt ionic interactions both within the protein itself and with negatively charged components of nucleotides, proteins and small molecules. Such alterations can occur at multiple lysine residues within a single protein, although their overall frequency varies considerably across the proteome. In mouse liver, for example, about half of all malonylated proteins contain a single site, while the frequency decreases sharply beyond four sites and only a few are extensively modified, the most heavily modified enzyme being carbamoyl‑phosphate synthetase 1 (CPS1) of the urea cycle with 31 sites. In the context of other lysine acylations, malonylation can be positioned as follows: While acetylation neutralizes lysine's positive charge, malonylation introduces a negative one, placing it among the acidic acylations alongside methylmalonylation, succinylation, glutarylation, 3‑hydroxy‑3‑methylglutarylation, 3‑methylglutaconylation, and 3‑methylglutarylation.
Salvinorin A is not scheduled at the federal level in the United States. Its molecular structure is unlike any Schedule I or II drug, so possession or sales is unlikely to be prosecuted under the Federal Analogue Act.
Avalglucosidase alfa, sold under the brand name Nexviazyme, is an enzyme replacement therapy medication used for the treatment of glycogen storage disease type II (Pompe disease). The most common side effects include headache, fatigue, diarrhea, nausea, joint pain (arthralgia), dizziness, muscle pain (myalgia), itching (pruritus), vomiting, difficulty breathing (dyspnea), skin redness (erythema), feeling of "pins and needles" (paresthesia) and skin welts (urticaria). Avalglucosidase alfa was approved for medical use in the United States in August 2021, and in the European Union in June 2022.
Sources: en.wikipedia.org
2 molecules of hydrogen + 1 molecule of oxygen = 2 molecules of water. The law of combining volumes of gases was announced publicly by Joseph Louis Gay-Lussac on the last day of 1808, and published in 1809. Since there was no direct evidence for Avogadro's molecular theory, very few chemists adopted Avogadro's hypothesis as generally valid until the Italian chemist Stanislao Cannizzaro argued convincingly for it during the First International Chemical Congress in 1860.
== External links == Motilin at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Nosek TM. "Section 6/6ch2/s6ch2_26". Essentials of Human Physiology. Archived from the original on 2016-03-24.
== Human homologue == Agouti signaling protein (ASP) is the human homologue of murine agouti. It is encoded by the human agouti gene on chromosome 20 and is a protein consisting of 132 amino acids. It is expressed much more broadly than murine agouti and is found in adipose tissue, pancreas, testes, and ovaries, whereas murine agouti is solely expressed in melanocytes. ASP has 85% similarity to the murine form of agouti. As ectopic expression of murine agouti leads to the development of the yellow obese syndrome, this is expected to be consistent in humans. The yellow obese syndrome increases the development of many chronic diseases, including obesity, type II diabetes mellitus and tumorigenesis. ASP has similar pharmacological activation to murine agouti, as melanocortin receptors are inhibited through competitive antagonism. Inhibition of melanocortin by ASP can also be through non-competitive methods, broadening its range of effects. The function of ASP differs to murine agouti. ASP effects the quality of hair pigmentation whereas murine agouti controls the distribution of pigments that determine coat color. ASP has neuroendocrine functions consistent with murine agouti, as it agonizes via AgRP neurons in the hypothalamus and antagonizes MSH at MC4Rs which reduce satiety signals. AgRP acts as an appetite stimulator and increases appetite while decreasing metabolism. Because of these mechanisms, AgRP may be linked to increased body mass and obesity in both humans and mice.
The enzyme is a cytochrome P450 protein containing heme, isolated from maize and other grasses. It requires a partner cytochrome P450 reductase for functional expression. This uses nicotinamide adenine dinucleotide phosphate. It is involved in the biosynthesis of protective and allelopathic compounds such as DIMBOA in some plants.
=== Classification methods === Classification methods use data to train a program (classifier) to distinguish positive examples of interacting protein/domain pairs with negative examples of non-interacting pairs. Popular classifiers used are Random Forest Decision (RFD) and Support Vector Machines. RFD produces results based on the domain composition of interacting and non-interacting protein pairs. When given a protein pair to classify, RFD first creates a representation of the protein pair in a vector. The vector contains all the domain types used to train RFD, and for each domain type the vector also contains a value of 0, 1, or 2. If the protein pair does not contain a certain domain, then the value for that domain is 0. If one of the proteins of the pair contains the domain, then the value is 1. If both proteins contain the domain, then the value is 2. Using training data, RFD constructs a decision forest, consisting of many decision trees. Each decision tree evaluates several domains, and based on the presence or absence of interactions in these domains, makes a decision as to if the protein pair interacts. The vector representation of the protein pair is evaluated by each tree to determine if they are an interacting pair or a non-interacting pair. The forest tallies up all the input from the trees to come up with a final decision. The strength of this method is that it does not assume that domains interact independent of each other. This makes it so that multiple domains in proteins can be used in the prediction.
Sources: en.wikipedia.org
Actaplanin is a complex of broad-spectrum antibiotics made by Actinoplanes bacteria. Research carried out by a group in Eli Lilly and Co. in 1984 identified several actaplanins using high-performance liquid chromatography. Actaplanins A, B1, B2, B3, C1 and G were shown to be composed of the same peptide core, an amino sugar, and varying amounts of glucose, mannose, and rhamnose.
Bicalutamide, sold under the brand name Casodex among others, is an antiandrogen medication that is primarily used to treat prostate cancer. It is typically used together with a gonadotropin-releasing hormone (GnRH) analogue or surgical removal of the testicles to treat metastatic prostate cancer (mPC). To a lesser extent, it is used at high doses for locally advanced prostate cancer (LAPC) as a monotherapy without castration. Bicalutamide was also previously used as monotherapy to treat localized prostate cancer (LPC), but authorization for this use was withdrawn following unfavorable trial findings. Besides prostate cancer, bicalutamide is limitedly used in the treatment of excessive hair growth and scalp hair loss in women, as a puberty blocker and component of feminizing hormone therapy for transgender girls and women, to treat gonadotropin-independent early puberty in boys, and to prevent overly long-lasting erections in men. It is taken by mouth. Common side effects of bicalutamide in men include breast growth, breast tenderness, and hot flashes. Other side effects in men include feminization and sexual dysfunction. Some side effects like breast changes and feminization are minimal when combined with castration. While the medication appears to produce few side effects in women, its use in women is not explicitly approved by the Food and Drug Administration (FDA) at this time. Use during pregnancy may harm the baby. In men with early prostate cancer, bicalutamide monotherapy has been found to increase the likelihood of death from causes other than prostate cancer.
Although naturally occurring double-strand breaks occur at a relatively low frequency in DNA, their repair often causes mutation. Non-homologous end joining (NHEJ) is a major pathway for repairing double-strand breaks. NHEJ involves removal of a few nucleotides to allow somewhat inaccurate alignment of the two ends for rejoining followed by addition of nucleotides to fill in gaps. As a consequence, NHEJ often introduces mutations.
=== Sample introduction === The first step in analysis is the introduction of the sample. This has been achieved in ICP-MS through a variety of means. The most common method is the use of analytical nebulizers. A nebulizer converts liquids into an aerosol, and that aerosol can then be swept into the plasma to create the ions. Nebulizers work best with simple liquid samples (i.e. solutions). However, there have been instances of their use with more complex materials like a slurry. Many varieties of nebulizers have been coupled to ICP-MS, including pneumatic, cross-flow, Babington, ultrasonic, and desolvating types. The aerosol generated is often treated to limit it to only smallest droplets, commonly by means of a Peltier cooled double pass or cyclonic spray chamber. Use of autosamplers makes this easier and faster, especially for routine work and large numbers of samples. A Desolvating Nebuliser (DSN) may also be used; this uses a long heated capillary, coated with a fluoropolymer membrane, to remove most of the solvent and reduce the load on the plasma. Matrix removal introduction systems are sometimes used for samples, such as seawater, where the species of interest are at trace levels, and are surrounded by much more abundant contaminants. Laser ablation is another method. Though less common in the past, it has become popular as a means of sample introduction, thanks to increased ICP-MS scanning speeds. In this method, a pulsed UV laser is focused on the sample and creates a plume of ablated material, which can be swept into the plasma.
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.