lyophilized powder comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-04-24. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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.
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.
| 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 |
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
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.
Propoxyphene should be used with extreme caution, if at all, in patients who have a history of substance/drug/alcohol abuse, depression with suicidal tendency, or who already take medications that cause drowsiness (e.g., antidepressants, muscle relaxants, pain relievers, sedatives, tranquilizers). Fatalities have occurred in such patients when propoxyphene was misused. Because of potential for side effects, this drug is on the list for high-risk medications in the elderly. On November 19, 2010, the FDA requested manufacturers withdraw propoxyphene from the US market, citing heart arrhythmia in patients who took the drug at typical doses. Tramadol, which lacks the cardiotoxicity, has been recommended instead of propoxyphene, as it is also indicated for mild to moderate pain, and is less likely to be misused or cause addiction than other opioids.
Trastuzumab emtansine, sold under the brand name Kadcyla, is an antibody-drug conjugate consisting of the humanized monoclonal antibody trastuzumab (Herceptin) covalently linked to the cytotoxic agent DM1. Trastuzumab alone stops growth of cancer cells by binding to the HER2 receptor, whereas trastuzumab emtansine undergoes receptor-mediated internalization into cells, is catabolized in lysosomes where DM1-containing catabolites are released and subsequently bind tubulin to cause mitotic arrest and cell death. Trastuzumab binding to HER2 prevents homodimerization or heterodimerization (HER2/HER3) of the receptor, ultimately inhibiting the activation of MAPK and PI3K/AKT cellular signalling pathways. Because the monoclonal antibody targets HER2, and HER2 is only over-expressed in cancer cells, the conjugate delivers the cytotoxic agent DM1 specifically to tumor cells. The conjugate is abbreviated T-DM1. In the EMILIA clinical trial of women with advanced HER2 positive breast cancer who were already resistant to trastuzumab alone, it improved median overall survival by 5.8 months (30.9 months vs. 25.1 months) compared to the combination of lapatinib and capecitabine. Based on that trial, the U.S. Food and Drug Administration (FDA) approved marketing on 22 February 2013. Trastuzumab emtansine was developed by Genentech, and is manufactured by Lonza.
The antimicrobial resistance crisis also extends to the food industry, specifically with food producing animals. With an ever-increasing human population, there is constant pressure to intensify productivity in many agricultural sectors, including the production of meat as a source of protein. Antibiotics are fed to livestock to act as growth supplements, and a preventive measure to decrease the likelihood of infections. Farmers typically use antibiotics in animal feed to improve growth rates and prevent infections. However, this is illogical as antibiotics are used to treat infections and not prevent infections. 80% of antibiotic use in the U.S. is for agricultural purposes and about 70% of these are medically important. Overusing antibiotics gives the bacteria time to adapt leaving higher doses or even stronger antibiotics needed to combat the infection. Though antibiotics for growth promotion were banned throughout the EU in 2006, 40 countries still use antibiotics to promote growth. This can result in the transfer of resistant bacterial strains into the food that humans eat, causing potentially fatal transfer of disease. While the practice of using antibiotics as growth promoters does result in better yields and meat products, it is a major issue and needs to be decreased to prevent antimicrobial resistance.
brevicaule complex. DNA analysis however shows that more than 99% of all current varieties of potatoes are direct descendants of a subspecies that once grew in the lowlands of south-central Chile. Most modern potatoes grown in North America arrived through European settlement and not independently from the South American sources. At least one wild potato species, Solanum fendleri, occurs in North America; it is used in breeding for resistance to a nematode species that attacks cultivated potatoes. A secondary center of genetic variability of the potato is Mexico, where important wild species used extensively in modern breeding are found, such as the hexaploid S. demissum, used as a source of resistance to the devastating late blight disease (Phytophthora infestans). Another relative native to this region, Solanum bulbocastanum, has been used to genetically engineer the potato to resist potato blight. Many such wild relatives are useful for breeding resistance to P. infestans. Little of the diversity found in Solanum ancestral and wild relatives is found outside the original South American range. This makes these South American species highly valuable in breeding. The importance of the potato to humanity is recognised in the United Nations International Day of Potato, to be celebrated on 30 May each year, starting in 2024.
Sources: en.wikipedia.org
It carries fowl tapeworms such as Choanotaenia infundibulum and the nematodes Subulura brumpti and Hadjelia truncata. Poultry have difficulty digesting the beetle and larva, and if they eat them, they can experience intestinal obstruction and gut lesions. Broiler chickens and turkey poults have slower weight gain when they feed on the beetle. Like other darkling beetles, this species produces defensive benzoquinone compounds that can be irritating to humans, causing asthma, headaches, rhinitis, conjunctivitis, corneal ulcers, and dermatitis with erythema and papules. The benzoquinones may be carcinogenic. Before the beetle became problematic in poultry, it was better known as a pest of stored goods, including wheat, barley, rice, oatmeal, soybeans, cowpeas, peanuts, linseed, cottonseed, tobacco, and dried meat. This beetle can become a household pest if it ends up near human habitation in old litter to be used as compost. It emerges when it is attracted to light from homes.
== June 10, 1915 (Thursday) == Francisco Lagos Cházaro became acting president of Mexico under convention of the Convention of Aguascalientes. Battle of Hébuterne — The French secured more trenches from the Germans on the southern flank. Second Battle of Garua — The remaining 249 German and native troops stationed in garrisons around Garua, Kamerun surrendered to British and French forces. British seaplane carrier HMS Ben-my-Chree arrived at Lesbos to provide a full squadron of fighter planes and bombers for the Allied landing forces at Gallipoli. Royal Navy torpedo boats HMS TB 10 and HMS TB 12 both struck mines in the North Sea, with a total 45 men lost. Filmmakers Edwin S. Porter and William E. Waddell tested the first 3D film to an audience at the Astor Theatre in New York City. The only Vorticist exhibition ever staged opened at the Doré Gallery in London. The popular Italian sports magazine Hurrà Juventus was first published for players and fans of the Juventus association football club in Turin. Born: Saul Bellow, Canadian-American writer, recipient of the Nobel Prize in Literature; as Solomon Bellows, in Lachine, Quebec, Canada (d. 2005) Inia Te Wiata, New Zealand Māori opera singer, known for his performances in The Marriage of Figaro, La bohème, Billy Budd and Gloriana; as Inia Morehu Tauhia Watene Iarahi Waihurihia Te Wiata, in Ōtaki, New Zealand (d. 1971) Died: William Hayman Cummings, 83, English organist and singer, founder of the Purcell Society and credited for creating the melody known today for the Christmas carol "Hark! The Herald Angels Sing" (b. 1831)
taxis A directional response by a cell or a population of cells to a specific stimulus; a movement or other activity occurring in a non-random direction and dependent on the direction from which the stimulus originated. This contrasts with kinesis, a response without directional bias.
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.
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.