A practical reference on Lyophilisation: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-01-18. Anything still debated is marked as such rather than presented as settled.
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
| Property | Value | Notes |
|---|---|---|
| 分子式 | C37H51N9O10S | 游离碱形式 |
| 等电点 | 约 6.5 | 估算值，随缓冲体系变化 |
| 主要降解途径 | 水解与氧化 | 侧链氧化最为常见 |
| 溶液储存 | 2 至 8 摄氏度避光 | 避免反复冻融 |
| 常规分析手段 | 反相色谱与质谱联用 | 氨基酸分析辅助核对 |
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
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.
Bodybuilders were previously thought to require protein with a higher BV than that of soy, which was additionally avoided due to its alleged estrogenic (female hormone) properties, though more recent studies have shown that soy actually contains phytoestrogens which compete with estrogens in the male body and can block estrogenic actions. Soy, flax, and other plant-based foods that contain phytoestrogens are also beneficial because they can inhibit some pituitary functions while stimulating the liver's P450 system (which eliminates hormones, drugs, and waste from the body) to more actively process and excrete excess estrogen.
=== 2015 === The index crossed the historical mark of 30,000 after repo rate cut announcement by RBI. The index plummeted by over 1,624.51 points on 24 August 2015, the then worst one-day point plunge in the index's history.
== Further reading == WHO traditional medicine strategy: 2014-2023. World Health Organization. 2013. hdl:10665/92455. ISBN 978-92-4-150609-0. Retrieved 1 April 2023. Baran GR, Kiana MF, Samuel SP (2014). "Chapter 2: Science, Pseudoscience, and Not Science: How Do They Differ?". Healthcare and Biomedical Technology in the 21st Century. Springer. pp. 19–57. doi:10.1007/978-1-4614-8541-4_2. ISBN 978-1-4614-8540-7. Barnes, Linda L. (2005). Needles, Herbs, Gods, and Ghosts: China, Healing, and the West to 1848. Cambridge, Mass: Harvard University Press. ISBN 0-674-01872-9. Shows early use of Chinese medicine not always perceived as "Chinese." Baum, Emily (2020). "Medicine and Public Health in Twentieth-Century China: Histories of Modernization and Change". History Compass. 18 (7) e12616. doi:10.1111/hic3.12616. S2CID 225622823. Liu, Lihong (2019). Classical Chinese Medicine. Translated by Weiss, Gabriel; Henry Buchtel; Sabine Wilms. Shatin, NT Hong Kong: Chinese University of Hong Kong Press; distributed by Columbia University Press. ISBN 978-988-237-057-9. Lloyd, G. E. R.; Sivin, Nathan (2002). The Way and the Word: Science and Medicine in Early China and Greece. New Haven: Yale University Press. ISBN 0-300-09297-0. Lo, Vivienne; Stanley-Baker, Michael, eds. (2022), Routledge Handbook of Chinese Medicine, New York: Routledge, ISBN 978-0-415-83064-5 The Open Access version of this book, available at Online Open Access Archived 4 March 2024 at the Wayback Machine, has been made available under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license.
== Therapies == A decade after the discovery of the RNAi mechanism in 1998, the pharmaceutical sector heavily invested in the research and development of siRNA therapy. There are several advantages that this therapy has over small molecules and antibodies. It can be administered quarterly or every six months. Another advantage is that, unlike small molecules and monoclonal antibodies that need to recognize a specific protein conformation, siRNA functions by Watson-Crick basepairing with mRNA. Therefore, any target molecule that needs to be treated with high affinity and specificity can be selected if the right nucleotide sequence is available. One of the biggest challenges researchers needed to overcome was the identification and establishment of a delivery system through which the therapies would enter the body. Another was that the immune system often mistakes RNAi therapies for remnants of infectious agents, which can trigger an immune response. Animal models did not accurately represent the degree of immune response seen in humans, and despite the promise of the treatment, investors divested from RNAi. However, there were a few companies that continued with the development of RNAi therapy for humans. Alnylam Pharmaceuticals, Sirna Therapeutics and Dicerna Pharmaceuticals are few of the companies still working on bringing RNAi therapies to market. It was learned that almost all siRNA therapies administered in the bloodstream accumulated in the liver. That is why most of the early drug targets were diseases that affected the liver.
Sources: en.wikipedia.org
==== APCI MS ==== The source for APCI is similar to ESI except that ions are formed by the interaction of the heated analyte solvent with a corona discharge needle set at a high electrical potential. Primary ions are formed immediately surrounding the needle, and these interact with the solvent to form secondary ions that ultimately ionize the sample. APCI is particularly useful for the analysis of nonpolar lipids such as triacylglycerols, sterols, and fatty acid esters.
== Candidacy relating to elections of the German Federal president == At the 2010 election for the German Federal President, Kermani served as a member of the 14th Federal Assembly at the recommendation of the Green Party of Hessen. And in 2017, Kermani was mentioned as a potential candidate for German Federal President in that year's federal presidential election. According to a report in Der Spiegel, then-SPD chairman Sigmar Gabriel, in cooperation with other parties, had intended to nominate Kermani to run for Federal President. However, the plan failed due to resistance from the Greens. In particular, Kermani was rejected by the Realos wing of the Green Party, because the Realos were aiming to form a Black-Green coalition (i.e. a coalition with the Christian Democrats) subsequent to the general federal elections and thus did not want to be seen as endorsing a Red-Red-Green (i.e. Social Democratic, Left Party and Green Party) coalition.
=== Industry growth === The global blood testing market was valued at approximately USD 96.62 billion in 2024 and is projected to reach USD 160.50 billion by 2030, growing at a compound annual growth rate (CAGR) of 8.83%. The DTC segment represents a rapidly growing portion of this market, fueled by increasing consumer health awareness and technological innovations in sample collection and analysis. North America dominates the market with the largest revenue share (approximately 44.83% in 2024), driven by well-established healthcare infrastructure, favorable regulatory environments in many states, and high consumer acceptance of self-directed healthcare services.
Sources: en.wikipedia.org
=== Honorary doctorates === Duterte declined an honorary doctor of laws degree offered by the University of the Philippines amid opposition from members of the university. Duterte was conferred an honorary doctorate degree for international relations or foreign diplomacy from the Moscow State Institute of International Relations on October 5, 2019. Duterte received an honorary Juris Doctor degree from his alma mater, San Beda College of Law in November 2023.
Spider angiomata or spider nevi happen when there is dilatation of vasculature beneath the skin surface. There is a central, red spot with reddish extensions that radiate outward. This creates a visual effect that resembles a spider. It occurs in about one-third of cases. The likely cause is an increase in estrogen. Cirrhosis causes a rise in estrogen due to increased conversion of androgens into estrogen. Palmar erythema, a reddening of the palm below the thumb and little finger, is seen in about 23% of cirrhosis cases, and results from increased circulating estrogen levels. Gynecomastia, or the increase of breast size in men, is caused by increased estradiol (a potent type of estrogen). This can occur in up to two-thirds of cases. Hypogonadism signifies a decreased functionality of the gonads. This can result in impotence, infertility, loss of sexual drive, and testicular atrophy. A swollen scrotum may also be evident. Liver size can be enlarged, normal, or shrunken in people with cirrhosis. As the disease progresses, the liver will typically shrink due to the result of scarring. Jaundice is the yellowing of the skin. It can additionally cause yellowing of mucous membranes notably of the white of the eyes. This phenomenon is due to increased levels of bilirubin, which may also cause the urine to be dark-colored.
The antagonist has a peptide moiety. The nomenclature of the somatostatin receptor antagonists is also based on this order. The structure of somatostatin receptor antagonists are similar to that of the agonists. Some agonists were already approved by the FDA for clinical use, such as In-DTPA-octreotide and Ga-DOTATATE. Development started after the discovery of modifications that can be done to the octreotide group, a ssrt selective subtype agonist, to cause its agonistic effects to be lost and gain antagonistic effects. Different subtype receptor antagonists were later developed. Research has mostly been done on the sstr2 receptor antagonist, as the sstr2 receptor is expressed on most tumors. Somatostatin receptor antagonists are divided by generation based on the type of the subtype receptor antagonist. The first generation consists of sst2-ANT and BASS, which are sstr2 selective; and sst3-ODAN-8, which is selective for sstr3. After initial results of their increased sensitivity to neurocrine tumors appeared, ssrt2 selective antagonists that had even higher affinity were developed. These were LM3, JR10, and JR11, which make up the second generation. JR11 was shown to be the most effective among these 3 antagonists, and compounds that entered further clinical development to act as a PET imaging agent or therapeutic agent carried this subtype antagonist. The presence of a chelator coupled to the subtype antagonist was shown to have an effect on the biologic properties. Compounds were developed with 3 macrocyclic chelators: DOTA, NODAGA, and CB-TE2A.
Sources: en.wikipedia.org
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。
甲硫氨酸侧链含硫醚，在氧气、光照或金属离子存在时容易被氧化。氧化产物极性略增，常在色谱图上表现为主峰之前的肩峰或前伸峰。
通常建议冷藏避光，并在较短时间内使用。不存在适用于所有配方的统一期限，具体取决于浓度、缓冲体系与容器材质。
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.