A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-17. Anything still debated is marked as such rather than presented as settled.
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.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
== Related enzymes == Prophenoloxidase is a modified form of the complement response found in some invertebrates, including insects, crabs and worms. Hemocyanin is homologous to the phenol oxidases (e.g. tyrosinase) since both enzymes sharing type copper active site coordination. Hemocyanin also exhibits PPO activity, but with slowed kinetics from greater steric bulk at the active site. Partial denaturation actually improves hemocyanin's PPO activity by providing greater access to the active site. Aureusidin synthase is homologous to plant polyphenol oxidase, but contains certain significant modifications. Aurone synthase catalyzes the formation of aurones. Aurone synthase purified from Coreopsis grandiflora shows weak tyrosinase activity against isoliquiritigenin, but the enzyme does not react with the classic tyrosinase substrates l-tyrosine and tyramine and must therefore be classified as catechol oxidase. Laccase, a multi-copper oxidase, is often considered a subclass of polyphenol oxidase. Laccase and polyphenol oxidase differ in the type of substrates that they catalyse. Catachol oxidase (a type of polyphenol oxidase) catalyses the oxidation of ortho-diphenols to ortho-quinones. Tyrosinase (another type of polyphenol oxidase), catalyses both the oxidation of monophenols to ortho-diphenols, and the subsequent oxidation of ortho-diphenols to ortho-quinones. Laccase, in contrast, catalyses the oxidation of para-diphenols to para-quinones.
=== PVAT AND ET-1 === ET-1 In addition to its direct vasoconstrictor effects, it causes changes in visceral and perivascular adipose tissue (PVAT), and may contribute to the pathogenesis of both insulin resistance and vascular dysfunction/damage. Perivascular adipose tissue seems to have anti contractile effect and this dilator effect was lost in obese patients. secondary to obesity, ET-1 high level changes on PVAT will lead to PVAT hypertrophy which will be associated with reduced partial oxygen pressure, an increase in the production of inflammatory cytokines such as TNF-α and IL-6, and elevation of reactive oxygen species. Thus, oxidative stress and hypoxia may promote imbalance in the production of vasoactive compounds and may affect vascular homeostasis by activating the ET-1 system.
== Cosmeses == Certain hair shampoos and ointments visually thicken existing hair, without affecting the growth cycle. There have also been developments in the fashion industry with wig design. The fashion accessory has also been shown to be a source of psychological support for women undergoing chemotherapy, with cancer survivors in one study describing their wig as a "constant companion". Other studies in women have demonstrated a more mixed psychosocial impact of hairpiece use. Specialized tattoos, commonly known as scalp micropigmentation, can mimic the appearance of a short buzzed haircut.
Sources: en.wikipedia.org
In 2024, the United States surpassed Qatar as the world's largest producer of the gas, having extracted 68 million SCM of helium that year compared to Qatar's 64 million SCM. An estimated 54 billion cubic feet (1.5×109 m3) deposit of helium was found in Tanzania in 2016, and a large-scale helium plant was opened in Ningxia, China in 2020. In the United States, most helium is extracted from the natural gas of the Hugoton and nearby gas fields in Kansas, Oklahoma, and the Panhandle Field in Texas. Much of this gas was once sent by pipeline to the National Helium Reserve, but since 2005, this reserve has been depleted and sold off, and it was expected to be largely depleted by 2021 under the October 2013 Responsible Helium Administration and Stewardship Act (H.R. 527). Despite efforts to sell the remaining reserve in 2021, the remnants of the National Helium Reserve were auctioned off by the Bureau of Land Management over the course of 3 years. It was finally sold to Messer Group on June 27, 2024. The helium fields of the western United States are emerging as an alternate source of helium supply, particularly those of the "Four Corners" region (the states of Arizona, Colorado, New Mexico and Utah). Diffusion of crude natural gas through special semipermeable membranes and other barriers is another method to recover and purify helium. In 1996, the U.S. had proven helium reserves in such gas well complexes of about 147 billion standard cubic feet (4.2 billion SCM).
== Pathogenesis == The pathophysiology of entrapment is complex because nerve tissue has many components (e.g. axon, myelin, endoneurium, perineurium, epineurium, blood vessels, etc) that may respond differently to various stressors affecting nerve function. The underlying mechanism of injury typically starts with interruptions in vascular supply. Both the acute and chronic forms of nerve entrapment involve initial changes in the microcirculatory environment. For the acute model, the sequence of events is typically an interruption of the blood supply followed by a metabolic block as the nerve stops functioning. For the chronic model, the sequence of events is a breakdown in the blood-nerve-barrier, followed by endoneurial edema and connective tissue fibrosis, followed by demyelination, and finally axonmetesis.
=== Pharmacokinetics === The bioavailability of methamphetamine is 67% orally, 79% intranasally, 67 to 90% via inhalation (smoking), and 100% intravenously. Following oral administration, methamphetamine is well-absorbed into the bloodstream, with peak plasma methamphetamine concentrations achieved in approximately 3.13–6.3 hours post ingestion. Methamphetamine is also well absorbed following inhalation and following intranasal administration. Because of the high lipophilicity of methamphetamine due to its methyl group, it can readily move through the blood–brain barrier faster than other stimulants, where it is more resistant to degradation by monoamine oxidase. The amphetamine metabolite peaks at 10–24 hours. Methamphetamine is excreted by the kidneys, with the rate of excretion into the urine heavily influenced by urinary pH. When taken orally, 30–54% of the dose is excreted in urine as methamphetamine and 10–23% as amphetamine. Following IV doses, about 45% is excreted as methamphetamine and 7% as amphetamine. The elimination half-life of methamphetamine varies with a range of 5–30 hours, but it is on average 9 to 12 hours in most studies. The elimination half-life of methamphetamine does not vary by route of administration, but is subject to substantial interindividual variability. CYP2D6, dopamine β-hydroxylase, flavin-containing monooxygenase 3, butyrate-CoA ligase, and glycine N-acyltransferase are the enzymes known to metabolize methamphetamine or its metabolites in humans.
Sources: en.wikipedia.org
=== Annual Buffalo festival === Hisar Annual Buffalo festival is held every year at the main campus on CIRB foundation day of 1 February, as an extension and awareness day where usually more than 4,000 farmers and breeders attend. Another annual Buffalo mela is held at the Bir Dosanjh subcampus every year on 11 December.
==== I. Blood Brain Barrier Disruption ==== The brain is protected by tight junctions in the endothelial cell wall in the capillaries, known as the blood-brain barrier (BBB). The BBB strictly regulates what passes into the brain from the blood, and while this function is highly desirable in healthy individuals, it also poses a barrier for therapeutics to enter the brain for cancer patients. Ultrasound was shown to disrupt the blood brain barrier in the mid 20th century, and in the early 2000's, microbubbles were shown to assist in a temporary permeabilization. Since then, ultrasound and microbubble therapy has been used to deliver therapeutics to the brain. As BBB disruption with ultrasound and microbubble treatment has shown to be a safe and promising treatment pre-clinically, two clinical trials are testing delivery of doxorubicin and carboplatin with microbubbles to increase drug concentration locally.
=== Infection === Common infectious causes of back pain include osteomyelitis, septic discitis, paraspinal abscess and epidural abscess. Infectious causes that lead to back pain involve various structures surrounding the spine. Osteomyelitis is the bacterial infection of the bone. Vertebral osteomyelitis is most commonly caused by staphylococci. Risk factors include skin infection, urinary tract infection, IV catheter use, IV drug use, previous endocarditis and lung disease. Spinal epidural abscess is commonly caused by severe infection with bacteremia. Risk factors include recent administration of epidurals, IV drug use or recent infection.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.