Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-06-19. Numbers and descriptions here follow the published literature rather than marketing material.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
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 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 |
|---|---|---|
| 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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
== Kinetics of deamidation == Deamidation reactions have been conjectured to be one of the factors that limit the useful lifetime of proteins. Deamidation proceeds much more quickly if the susceptible amino acid is followed by a small, flexible residue such as glycine whose low steric hindrance leaves the peptide group open for attack. Deamidation reactions also proceed much more quickly at elevated pH (>10) and temperature. The endoprotease, Glu-C, has shown specificity to only glutamic acid when in specific pH conditions (4.5 and 8.0) and cleaved the C-terminal side when in a solution with Tris-HCl, bicarbonate, or acetate.
=== Supplementation === Patients are recommended to take folic acid and vitamin B12 supplement even if levels are normal when they are on pemetrexed therapy. (In clinical trials for mesothelioma, folic acid and B12 supplementation reduced the frequency of adverse events.) It is also recommended for patients to be on a glucocorticoid (e.g. dexamethasone) on the day prior, day of, and day after pemetrexed infusion to avoid skin rashes.
=== Post‑Fight bonus increases === Beginning in January 2026, starting with UFC 324, the UFC increased its post‑fight bonus structure, raising Performance of the Night and Fight of the Night awards from $50,000 to $100,000, and introducing additional $25,000 bonuses for any knockout or submission not selected among the standard four post‑fight awards.
Direct interaction with DNA is the simplest and the most direct method by which a protein changes transcription levels. Genes often have several protein binding sites around the coding region with the specific function of regulating transcription. There are many classes of regulatory DNA binding sites known as enhancers, insulators and silencers. The mechanisms for regulating transcription are varied, from blocking key binding sites on the DNA for RNA polymerase to acting as an activator and promoting transcription by assisting RNA polymerase binding. The activity of transcription factors is further modulated by intracellular signals causing protein post-translational modification including phosphorylation, acetylation, or glycosylation. These changes influence a transcription factor's ability to bind, directly or indirectly, to promoter DNA, to recruit RNA polymerase, or to favor elongation of a newly synthesized RNA molecule. The nuclear membrane in eukaryotes allows further regulation of transcription factors by the duration of their presence in the nucleus, which is regulated by reversible changes in their structure and by binding of other proteins. Environmental stimuli or endocrine signals may cause modification of regulatory proteins eliciting cascades of intracellular signals, which result in regulation of gene expression. It has become apparent that there is a significant influence of non-DNA-sequence specific effects on transcription.
Sources: en.wikipedia.org
Histoire et dictionnaire de Paris [History and dictionary of Paris] (in French). Paris: Éditions Robert-Laffont. Auguste, Jal (1872). Dictionnaire critique de biographie et d'histoire [Critical Dictionary of Biography and History] (in French). Paris: Éditions Plon. Piot, Eugène (1873). État civil de quelques artistes français [Marital status of some French artists] (in French). Paris: Librairie Pagnerre.
==== Glutathione ==== Glutathione or its homologues, e.g. homoglutathione in Fabaceae; hydroxymethylglutathione in Poaceae are the major water-soluble non-protein thiol compounds present in plant tissue and account for 1-2% of the total sulfur. The content of glutathione in plant tissue ranges from 0.1 – 3 mM. Cysteine is the precursor to glutathione (and its homologues). First, γ-glutamylcysteine is synthesized from cysteine and glutamate catalyzed by gamma-glutamylcysteine synthetase. Second, glutathione is synthesized from γ-glutamylcysteine and glycine (in glutathione homologues, β-alanine or serine) catalyzed by glutathione synthetase. Both steps of the synthesis of glutathione are ATP-dependent. Glutathione is maintained in the reduced form by an NADPH-dependent glutathione reductase, and the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) generally exceeds a value of 7. In sulfur metabolism glutathione is reductant for the conversion of APS to sulfite. It is also the major transport form of reduced sulfur in plants. Roots likely largely depend for their reduced sulfur supply on shoot/root transfer of glutathione via the phloem, since the reduction of sulfur occurs predominantly in the chloroplast. Glutathione is also involved in the reduction and assimilation of selenite into selenocysteine.
=== Teratogenicity === Chemotherapy is teratogenic during pregnancy, especially during the first trimester, to the extent that abortion usually is recommended if pregnancy in this period is found during chemotherapy. Second- and third-trimester exposure does not usually increase the teratogenic risk and adverse effects on cognitive development, but it may increase the risk of various complications of pregnancy and fetal myelosuppression. Female patients of reproductive potential should use effective contraception during chemotherapy and for a few months after the last dose (e.g. 6 month for doxorubicin). In males previously having undergone chemotherapy or radiotherapy, there appears to be no increase in genetic defects or congenital malformations in their children conceived after therapy. The use of assisted reproductive technologies and micromanipulation techniques might increase this risk. In females previously having undergone chemotherapy, miscarriage and congenital malformations are not increased in subsequent conceptions. However, when in vitro fertilization and embryo cryopreservation is practised between or shortly after treatment, possible genetic risks to the growing oocytes exist, and hence it has been recommended that the babies be screened.
Sources: en.wikipedia.org
CSL Limited is an Australian multinational specialty biotechnology company that researches, develops, manufactures, and markets products to treat and prevent serious human medical conditions. CSL's product areas include blood plasma derivatives, vaccines, antivenom, and cell culture reagents used in various medical and genetic research and manufacturing applications. The company was established in 1916 as Commonwealth Serum Laboratories and was wholly owned by the Australian federal government until its privatisation in 1994.
=== Intellectual property issues === Ayahuasca has stirred debate regarding intellectual property protection of traditional knowledge. In 1986 the US Patent and Trademarks Office (PTO) allowed the granting of a patent on the ayahuasca vine B. caapi. It allowed this patent based on the assumption that ayahuasca's properties had not been previously described in writing. Several public interest groups, including the Coordinating Body of Indigenous Organizations of the Amazon Basin (COICA) and the Coalition for Amazonian Peoples and Their Environment (Amazon Coalition) objected. In 1999 they brought a legal challenge to this patent which had granted a private US citizen "ownership" of the knowledge of a plant that is well-known and sacred to many Indigenous peoples of the Amazon, and used by them in religious and healing ceremonies. Later that year the PTO issued a decision rejecting the patent, on the basis that the petitioners' arguments that the plant was not "distinctive or novel" were valid; however, the decision did not acknowledge the argument that the plant's religious or cultural values prohibited a patent. In 2001, after an appeal by the patent holder, the US Patent Office reinstated the patent, albeit to only a specific plant and its asexually reproduced offspring. The law at the time did not allow a third party such as COICA to participate in that part of the reexamination process. The patent, held by American entrepreneur Loren Miller, expired in 2003.
The king cobra has an eminent position in the mythology and folklore of India, Bangladesh, Sri Lanka and Myanmar. A ritual in Myanmar involves a king cobra and a female snake charmer. The charmer is a priestess who is usually tattooed with three pictograms and kisses the snake on the top of its head at the end of the ritual. Members of the Pakokku clan tattoo themselves with ink mixed with cobra venom on their upper bodies in a weekly inoculation that they believe would protect them from the snake, though no scientific evidence supports this. It is regarded as the national reptile of India. In India, the king cobra is believed to possess exceptional memory; according to a myth, the killer of a king cobra stays in the eyes of the snake as an image, which is later picked up by the snake's partner and used to hunt down the killer for revenge. Because of this myth, whenever a cobra is killed, especially in India, the head, if not the entire body, is either crushed or burned to destroy the eyes completely. In Bangkok's Bang Khun Thian district is a shrine to the king cobra by Rama II Road that was built after the nest and young of a large female king cobra were destroyed during the construction of the road. The original shrine is dedicated to a female spirit associated with the cobra. Nearby stands another shrine dedicated to a male spirit, believed to be the mate of the female king cobra; according to local belief, he later came there to meditate and perform ascetic practices in dedication to the female cobra and her offspring after their deaths.
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.
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.