A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-05. Anything still debated is marked as such rather than presented as settled.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
| Property | Value | Notes |
|---|---|---|
| Typical analytical method | Reversed-phase HPLC with UV detection | Separates target peptide from truncated and oxidised forms |
| Identity confirmation | LC-MS or ESI-MS | Compares observed and calculated molecular ion |
| Primary degradation route | Methionine oxidation | Forms the sulfoxide; monitored as an early-eluting peak |
| Short-term storage | 2 to 8 degrees Celsius | Applies to working vials and reconstituted portions |
| Common synonyms | ACTH(4–10) analogue, MEHFPGP | Descriptive names used in laboratory catalogues |
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.
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.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
In his public letter of resignation, he cited his reasons as being the lack of "the possibility of fulfilling, with the necessary total transparency, autonomy, and freedom, what Cuban Masonic legislation defines as required to carry out this responsibility." Alfonso Vidal said that the Grand Lodge was in the practice of "distorting Masonic Law." He also noted that because he had signed Decree 634, it was virtually impossible for him to have abandoned his post. He wrote that he was aware that he had been wrongfully terminated through an Extraordinary Session of the Supreme Court of Masonic Justice, and that those who signed his tacit resignation were being ordered to do so by the State Security Unit. He lamented the nature of the "...political gangsterism that works in the Grand Lodge of Cuba." Alfonso Vidal wrote that: "Cuban Masons have the right to know that our institution is under one of the greatest attacks it has received since January 1, 1959." He called back on the events surrounding the case of Grand Commander Viñas Alonso, and the letter that Viñas Alonso had sent to President Díaz-Canel. He said that the situation since Díaz-Canel had sent the State Security Unit after Viñas Alonso, the situation in Cuban Freemasonry had become increasingly difficult to operate within as an ethical and moral Grand Master. He could not fulfill his obligations as Grand Master for the fear of what actions the Cuban state might take against him. He also urged Cuban Freemasons to reject anyone from the Cuban intelligence community to ever again gain high office in the Grand Lodge.
Maggots in a single day would clean a wound much better than any agents we had at our command ... I am sure I saved many lives by their use. He recorded a high survival rate in patients he treated with maggots. During World War I, orthopedic surgeon William S. Baer recorded the case of a soldier left for several days on the battlefield who had sustained compound fractures of the femur and large flesh wounds. The soldier arrived at the hospital with maggots infesting his wounds but had no fever or other signs of infection and survived his injuries, which would normally have been fatal. After the war, Baer began using maggot therapy at Boston Children's Hospital in Massachusetts. There were reports that American prisoners of war of the Japanese in World War II resorted to maggot therapy to treat severe wounds. A survey of US Army doctors published in 2013 found that 10% of them had used maggot therapy.
In 2011, food accounted for 70% of Indian retail, but was under-represented by organised retail. A.T. Kearney estimates India's organised retail had a 31% share in clothing and apparel, while the home supplies retail was growing between 20% and 30% per year. These data correspond to retail prospects prior to November announcement of the retail reform. It might be true that India has the largest number of shops per inhabitant. However, detailed figures are available for Belgium, the Netherlands, and Luxembourg. In Belgium, the number of outlets is approximately 8 per 1,000 inhabitants, while in the Netherlands it is 6 per 1,000 inhabitants. Therefore, the Indian figure must be significantly higher.
In a water molecule, the hydrogen atoms form a 104.5° angle with the oxygen atom. The hydrogen atoms are close to two corners of a tetrahedron centered on the oxygen. At the other two corners are lone pairs of valence electrons that do not participate in the bonding. In a perfect tetrahedron, the atoms would form a 109.5° angle, but the repulsion between the lone pairs is greater than the repulsion between the hydrogen atoms. The O–H bond length is about 0.096 nm. Other substances have a tetrahedral molecular structure, for example methane (CH4) and hydrogen sulfide (H2S). However, oxygen is more electronegative than most other elements, so the oxygen atom has a negative partial charge while the hydrogen atoms are partially positively charged. Along with the bent structure, this gives the molecule an electrical dipole moment and it is classified as a polar molecule. Water is a good polar solvent, dissolving many salts and hydrophilic organic molecules such as sugars and simple alcohols such as ethanol. Water also dissolves many gases, such as oxygen and carbon dioxide – the latter giving the fizz of carbonated beverages, sparkling wines and beers. In addition, many substances in living organisms, such as proteins, DNA and polysaccharides, are dissolved in water. The interactions between water and the subunits of these biomacromolecules shape protein folding, DNA base pairing, and other phenomena crucial to life (hydrophobic effect). Many organic substances (such as fats and oils and alkanes) are hydrophobic, that is, insoluble in water.
Sources: en.wikipedia.org
=== Leadership === Roger D. Cone began his tenure as the Mary Sue Coleman Director of the University of Michigan Life Sciences Institute in September 2016. A leading researcher in brain regulation of body weight, Cone also serves as vice provost and director of U-M's biosciences initiative. The managing director is Anna Schork. The institute's first director was Jack E. Dixon. In 2002, Mary Sue Coleman, U-M's president, appointed cell biologist and expert on insulin signaling Alan R. Saltiel as director. Saltiel served as the director until 2015, followed by interim director Stephen Weiss, who led the institute from 2015 to 2016.
== Colors and materials == Conventional LEDs are made from a variety of inorganic semiconductor materials. The following table shows the available colors with wavelength range, voltage drop and material:
For services to Health and Social Care, particularly during Covid-19. Isabelle Trowler. Chief Social Worker for Children and Families, Department for Education. For services to Children's Social Care. Professor Robert Adrianus Leonardus Van de Noort. Chair, Thames Regional Flood and Coastal Committee and Vice Chancellor, University of Reading. For services to Science, to Flood Risk Management and to Sustainability. Stephen Banks Walker. Director, Strengthening Families, Leeds City Council. For services to Children and Families. Vivien Waterfield. Deputy Chief Executive, Home-Start. For services to Early Years Learning. Dr. Charles Nicholas Woodburn. Chief Executive Officer, BAE Systems. For services to International Trade and Skills Development. John Mark Yallop. Lately Chair, Financial Markets Standards Board. For services to the Financial Sector and to Charity. International list The Honourable Albert Isola, Minister for Financial Services and Gaming, Gibraltar. For services to the Financial and Digital Industries in Gibraltar. George Koukis, Founder Temenos and Chair, The Mozartists. For services to Music, to Medicine and to Education.
Sources: en.wikipedia.org
=== February === 4 February – Police investigating the disappearance of Nicola Bulley, who went missing on 27 January while walking her dog, believe she may have fallen into the River Wyre at St Michael's on Wyre, Lancashire. 7 February – David Carrick, one of the UK's most prolific sex offenders, is sentenced at Southwark Crown Court to 36 life sentences with a minimum term of 30 years imprisonment. 10 February – A large World War II bomb discovered in Great Yarmouth explodes as work is being carried out to defuse it, causing a blast that is heard for 15 miles. During a demonstration in Knowsley, Merseyside, protesters clash with police outside a hotel that provides refuge for asylum seekers. 17 February – The £2 cap on bus fares in England is extended for three months until 30 June amid concerns some routes could be lost if it were to end. Buckinghamshire Council approves proposals for an £800m expansion of Pinewood Studios near Iver Heath. 19 February – Police searching for Nicola Bulley, missing since 27 January, say they have found a body in the River Wyre. 20 February – Mayor of London Sadiq Khan announces the launch of a £130m scheme to give every primary school pupil in London free school meals during the 2023–24 academic year. Junior doctors in England vote to strike in their ongoing dispute for a 26% pay rise, and will stage a 72-hour walkout. The British Medical Association maintaines junior doctors' pay has been cut by 26% since 2008 after inflation is considered.
: deflection offset AFM allows us to obtain a high-resolution image of multiple types of surfaces while the tip of the cantilever can be used to obtain information about mechanical properties. Computer simulations are also being progressively used to test theories and complement experimental studies. The most used computer method is molecular dynamics simulation, which uses Newton's equations of motion for the atoms or molecules in the system. Other techniques such direct probe method are used to determine the adhesive properties of nanomaterials. Both the technique and simulation are coupled with transmission electron microscope (TEM) and AFM techniques to provide results. Mechanical properties of common nanomaterials classes: Crystalline metal nanomaterials: Dislocations are one of the major contributors toward elastic properties within nanomaterials similar to bulk crystalline materials. Despite the traditional view of there being no dislocations in nanomaterials. Ramos, experimental work has shown that the hardness of gold nanoparticles is much higher than their bulk counterparts, as there are stacking faults and dislocations forming that activate multiple strengthening mechanisms in the material. Through these experiments, more research has shown that via nanoindentation techniques, material strength; compressive stress, increases under compression with decreasing particle size, because of nucleating dislocations. These dislocations have been observed using TEM techniques, coupled with nanoindentation.
The Library of Congress, through both the librarian of Congress and the register of copyrights, is responsible for authorizing exceptions to Section 1201 of Title 17 of the United States Code as part of the Digital Millennium Copyright Act. This process is done every three years, with the register receiving proposals from the public and acting as an advisor to the librarian, who issues a ruling on what is exempt. After three years have passed, the ruling is no longer valid and a new ruling on exemptions must be made.
Sources: en.wikipedia.org
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.
Oxidation of the methionine residue to the sulfoxide is a frequently reported change, and it usually appears as an earlier-eluting peak in reversed-phase chromatography. Backbone hydrolysis products can also accumulate in aqueous solution.
Liquid chromatography coupled with mass spectrometry is the usual approach, because the observed molecular ion can be compared with a calculated mass of about 813.9 Da. Retention time alone does not establish identity.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.