反相色谱 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-07-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
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.
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.
== Applications == The Bergmann degradation is intended for and has been used as a method for peptide sequencing. It was also proposed for use in cleaving the 3,4-bond of the penicillin nucleus. The compound 2,2-dimethyl-6-phthalimido-3-penamyl isocyanate was arrived at through various means, including the Curtius rearrangement, and it was envisioned that it could undergo the Bergmann degradation to form the desired aldehyde as well as the urea by-product. Though the Bergmann degradation was indeed possible, it was discovered that simple dilute acid hydrolysis would suffice in forming the desired product.
The vaginal support structures are those muscles, bones, ligaments, tendons, membranes and fascia, of the pelvic floor that maintain the position of the vagina within the pelvic cavity and allow the normal functioning of the vagina and other reproductive structures in the female. Defects or injuries to these support structures in the pelvic floor leads to pelvic organ prolapse. Anatomical and congenital variations of vaginal support structures can predispose a woman to further dysfunction and prolapse later in life. The urethra is part of the anterior wall of the vagina and damage to the support structures there can lead to incontinence and urinary retention.
1D-chiro-Inositol or D-chiro-inositol (often abbreviated DCI) is a chemical substance with formula C6H12O6, one of the nine isomers of cyclohexane-1,2,3,4,5,6-hexol (which may be collectively called "inositol"). The molecule has a ring of six carbon atoms, each bound to one hydrogen atom and one hydroxyl (OH) group. The hydroxyls on atoms 1, 2, and 4, in counterclockwise order, lie above the plane of the ring. The molecule being distinct from its mirror image, the compound is chiral, hence its name. Its enantiomer (mirror compound) is 1L-chiro-inositol. Compared to its more common isomer myo-inositol, DCI seems to have relatively minor roles in biochemistry and medicine, mostly connected to the biochemistry of insulin and other hormones.
=== Legal disputes and events === 2020 MusclePharm subleased its Burbank, CA office and legally relocated to Calabasas, CA. 2018 In 2018, MusclePharm announced that it was relocating its headquarters from Denver, CO to Burbank, CA as a part of a restructuring deal. 2016 Protein supplement maker Hi-Tech Pharmaceuticals sued MusclePharm for artificially inflating the level of protein in its Arnold Schwarzenegger Series Iron Mass product - claiming MusclePharm lied to consumers about the amount of actual protein in the product, violating federal competition and state consumer protection laws. MusclePharm was sued by Capstone Nutrition for breach of contract. Capstone alleged that MusclePharm has breached the parties' manufacturing contract and is seeking $65 million in damages. 2015 MusclePharm signed a development and manufacturing supply agreement with Capstone Nutrition and purchased a 20% interest in Capstone's parent company (INI). MusclePharm was charged by the U.S. Securities and Exchange Commission with infractions related to a multitude of accounting and disclosure violations. The investigation had found that MusclePharm failed to report, or grossly misrepresented, approximately $500,000 in benefits paid to three current or former executives and chairmen. The SEC also discovered that MusclePharm issued stock without a registration statement when it entered into numerous transactions with third parties that agreed in exchange for company shares to pay cash to MusclePharm vendors.
Sources: en.wikipedia.org
==== Rhizomes ==== The rhizomes are 60–14 cm (23.6–5.5 in) long, 0.5–2.5 cm (0.20–0.98 in) in diameter, yellowish white to yellowish brown, smooth, and with nodes and internodes. Lotus root is a moderate-calorie root vegetable (100 g of root stem provides about 74 calories) and is composed of several vitamins, minerals, and nutrients: 83.80% water, 0.11% fat, 1.56% reducing sugar, 0.41% sucrose, 2.70% crude protein, 9.25% starch, 0.80% fibre, 0.10% ash and 0.06% calcium. 100 g of root provides 44 mg of vitamin C or 73% of daily recommended values (RDA). Lotus rhizome and its extracts have shown diuretic, psychopharmacological, anti-diabetic, anti-obesity, hypoglycemic, antipyretic and antioxidant activities.
2 March Chinese People's Liberation Army troops attacked Soviet border guards on Zhenbao Island, marking a new low in relations between North Vietnam's principal allies. Village and hamlet elections were held throughout South Vietnam, largely free of PAVN/VC interference.
== Significance in carryover assessment == The pathological range of measurement could be of several order to reference interval(e.g., Sex hormone, Tumor marker, Troponin...etc.). A small portion of carryover could lead to erroneous results.
=== Deconvolution of libraries cleaved from the solid support === If the synthesized molecules of a combinatorial library are cleaved from the solid support, a soluble mixture forms. In such solution, millions of different compounds may be found. When this synthetic method was developed, it first seemed impossible to identify the molecules, and to find molecules with useful properties. Strategies for identification of the useful components have been developed, however, to solve this problem. All these strategies are based on synthesis and testing of partial libraries. An early iterative strategy was devised by Furka in 1982. The method was later independently published by Erb et al. under the name "Recursive deconvolution"
=== Pharmacokinetics === Amitriptyline is readily absorbed from the gastrointestinal tract (90–95%). Absorption is gradual with the peak concentration in blood plasma reached after about 4 hours. Extensive metabolism on the first pass through the liver leads to average bioavailability of about 50% (45%-53%). Amitriptyline is metabolized mostly by CYP2C19 into nortriptyline and by CYP2D6 leading to a variety of hydroxylated metabolites, with the principal one among them being (E)-10-hydroxynortriptyline (see metabolism scheme), and to a lesser degree, by CYP3A4. Nortriptyline, the main active metabolite of amitriptyline, is an antidepressant on its own right. Nortriptyline reaches 10% higher level in the blood plasma than the parent drug amitriptyline and 40% greater area under the curve, and its action is an important part of the overall action of amitriptyline. Another active metabolite is (E)-10-hydroxynortriptyline, which is a norepinephrine uptake inhibitor four times weaker than nortriptyline. (E)-10-hydroxynortiptyline blood level is comparable to that of nortriptyline, but its cerebrospinal fluid level, which is a close proxy of the brain concentration of a drug, is twice higher than nortriptyline's. Based on this, (E)-10-hydroxynortriptyline was suggested to significantly contribute to the antidepressant effects of amitriptyline. Blood levels of amitriptyline and nortriptyline and pharmacokinetics of amitriptyline in general, with clearance difference of up to 10-fold, vary widely between individuals.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
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。