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ipamorelin-notes.peptides1126.com › Topic › �ƒŒ景与分子特征 — Worked Examples

�ƒŒ景与分子特征 — Worked Examples

By Editorial Desk · published 2026-07-16 · last reviewed 2026-08-01 · Topic

Everything below concerns GHS-R1a. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.

Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.

背景与分子特征

从用途定位看,ipamorelin 目前主要以研究用肽的身份被讨论,未见主要药品监管机构将其批准为治疗药物。市售材料通常标注仅供研究使用,不得用于人体或诊断程序。文献中它常与生长激素促分泌素、GHS-R1a 激动剂、胃饥饿素拟似物等表述并列出现。既有研究的样本量普遍偏小,因此对其效应强度与一致性的描述应保持谨慎。

Ipamorelin 是一种合成五肽,序列为 Aib-His-D-2-Nal-D-Phe-Lys-NH2,分子式 C38H49N9O5,游离碱分子量约 711.85 g/mol。它属于生长激素促分泌素(GHS)家族,作用靶点是胃饥饿素受体 GHS-R1a。该化合物由诺和诺德的研究团队在二十世纪九十年代末报道,设计目标是提高对生长激素释放的选择性。C 端酰胺化与 N 端 Aib 残基是两个用于抵抗肽酶降解的结构特征。

在 GHS 家族中,早期肽类如 GHRP-6 与 GHRP-2 会同时促进生长激素、皮质醇与催乳素的释放,并明显增加食欲。Ipamorelin 在动物与早期人体研究中表现出对生长激素释放的相对选择性,对上述其他激素的影响较小。这种差异通常归因于受体结合模式与下游信号偏向的不同,而完整的分子解释仍有待补充。需要区分的是,选择性是研究观察中的相对程度,并非绝对界限。

Storage Stability and Analytical Verification

Lyophilized material is generally stored frozen and protected from light and moisture. Typical recommendations place dry powder at temperatures well below freezing, while reconstituted solutions are kept cold and used within a defined window. Repeated freezing and thawing should be avoided because it can promote aggregation and loss of material. The choice of solvent matters as well; compatibility with the intended diluent should be checked before preparation. These handling practices aim to preserve both the quantity and the integrity of the peptide.

Verification of identity and purity relies on analytical methods used across peptide chemistry. Reverse-phase high-performance liquid chromatography separates components by hydrophobicity and provides a purity estimate. Mass spectrometry confirms molecular mass and helps detect modifications. Together these techniques give complementary information about whether a sample matches its expected structure. Results depend on method parameters and reference standards, so reported purity values are meaningful only when the analytical conditions are stated. Consistency between laboratories requires comparable protocols and well-characterized reference materials.

Peptides such as ipamorelin are subject to chemical and physical degradation. Hydrolysis of peptide bonds, oxidation of susceptible residues, and aggregation are common pathways that reduce purity over time. The rate of these processes depends on temperature, moisture, pH, and the number of freeze-thaw cycles a sample undergoes. Because the compound is typically handled as a lyophilized powder, controlling moisture during storage is a central concern. Degradation products can be detected with separation techniques that resolve the parent peptide from related impurities.

Ipamorelin at a glance

PropertyValueNotes
分子式C38H49N9O5五肽,C 端酰胺化
分子量约 711.85 g/mol游离碱形式
外观白色至类白色冻干粉研究用材料的常见形态
溶解性溶于水及 DMSO 等极性溶剂建议现配现用
储存温度-20 °C 或更低干燥、避光、限制冻融次数

Receptor Mechanism and Secretagogue Action

One distinguishing feature reported in animal studies is selectivity. Ipamorelin stimulated growth hormone release with limited elevation of adrenocorticotropic hormone or cortisol compared with earlier secretagogues such as GHRP-6. This pattern has been described as more selective for the growth hormone axis. The finding comes mainly from preclinical work, and the degree to which it holds across species and doses is not fully settled. Reports also describe effects on gastric motility in animal models, suggesting activity outside the pituitary, though the clinical relevance of this observation is uncertain.

Ipamorelin is a synthetic pentapeptide that acts on the growth hormone secretagogue receptor, also known as the ghrelin receptor. Its sequence contains five amino acid residues, including a non-natural residue that increases stability against enzymatic breakdown. The compound was developed in the 1990s as part of research into small peptides that stimulate pituitary hormone release. Unlike larger protein hormones, it can be produced by solid-phase peptide synthesis and characterized by standard analytical methods.

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Analytical Characterisation and Storage

The lyophilised solid is normally held at -20 °C or colder, shielded from light and moisture. Stability in that state is measured in years, although shelf life depends on residual water content and the container seal. Once dissolved, the peptide is more fragile: aqueous solutions are commonly kept at 2-8 °C and used within days to weeks, and repeated freeze-thaw cycling is avoided. Strongly acidic or basic conditions accelerate hydrolysis, and prolonged exposure to them can strip the terminal amide.

Purity assessment for this peptide relies mainly on reversed-phase high-performance liquid chromatography. A C18 column with a water-acetonitrile gradient containing trifluoroacetic acid separates the target from truncated sequences and oxidation products. Detection near 214 nm exploits the amide backbone, while the aromatic side chains allow additional monitoring close to 280 nm. Reported purity values depend on the method, so a certificate of analysis carries weight only when gradient, column and integration parameters are given.

Background and Structural Identity

The compound was developed at Novo Nordisk during the 1990s as part of a programme seeking secretagogues with improved selectivity. It was described in the peer-reviewed literature in 1998 alongside related pentapeptides from the same series. Investigators advanced it because it raised growth hormone output in animal models while leaving other pituitary hormones comparatively unaffected. The development code NNC 26-0161 appears in earlier reports, and ipamorelin later became the common designation in published work.

Selectivity is the property most often attached to this peptide. Published animal and early human studies record increases in growth hormone release after administration, with adrenocorticotropic hormone and cortisol responses remaining small by comparison. Effects on appetite-related pathways also appear weaker than those reported for several earlier secretagogues. Reviews that compare members of the growth hormone secretagogue family cite these findings frequently, though the receptor-level explanation for the selectivity continues to be debated rather than settled.

Ipamorelin is a synthetic pentapeptide classified as a growth hormone secretagogue. Its sequence, Aib-His-D-2-Nal-D-Phe-Lys-NH2, combines three non-proteinogenic residues with a C-terminal amide. The N-terminal aminoisobutyric acid unit and the two aromatic D-amino acids distinguish it from peptides assembled only from standard L-amino acids. Its formula is C38H49N9O5, corresponding to an average mass near 711.9 Da. At neutral pH the molecule carries a net positive charge, a property that shapes its behaviour in chromatographic and electrophoretic systems.

Background And Receptor Mechanism

Compared with other secretagogues such as GHRP-2, GHRP-6, and hexarelin, ipamorelin is described as more selective. Published animal work reports little or no increase in adrenocorticotropic hormone, cortisol, or prolactin at doses that release growth hormone. This selectivity is the property most often cited in the research literature. Whether the same profile holds across species and dosing schedules remains an open question, since human data are limited and come largely from small studies.

Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue family. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, and its molecular mass is approximately 711.9 daltons. The compound was described in the late 1990s by researchers seeking molecules that release growth hormone with fewer side effects than earlier secretagogues. It is a laboratory and research compound, not an approved medicine in most jurisdictions.

Background from the literature

These CSPs are compatible with NP/RP and SFC and also used for analytical, semi-preparative and preparative separations. Many screening research studies conducted at different labs go to suggest that the four CSPs namely Chiralcel OD, Chiralcel OJ, Chiralpak AD, and Chiralpak As are capable of resolving more than 80% of the chiral separations due to their adaptability and high loading capacity. These four polysaccharide chiral stationary stationary phases are referred to as the "golden four". Polysaccharide CSPs are prepared with high quality silica support on to which the polymeric chiral selector (amylose/cellulose dr.) is physically coated (coated CSP) or chemically immobilized (immobilized CSP). Separations can be done in normal phase, reversed-phase, and polar organic mode. While working with coated polysaccharide CSP solvent selection should be done with caution. One should not use drastic solvents such as dichloromethane, chloroform, toluene, ethyl acetate, THF; 1,4-dioxane; acetone; DMSO, etc. These so called "non-standard" solvents will dissolve the silica and irreversibly destroy the stationary phase. The limited resistance of these coated phases to many solvents lead to the development of immobilized polysaccharide CSP. The table below presents some of the immobilized CSP commercially available and with the alternates wherever accessible.

== Treatment == In November 2020, the U.S. Food and Drug Administration approved lonafarnib, which helps prevent buildup of defective progerin and similar proteins. A clinical trial in 2018 points to significantly lower mortality rates – treatment with lonafarnib alone compared with no treatment (3.7% vs. 33.3%) – at a median post-trial follow-up time span of 2.2 years. The drug, given orphan drug status and Pediatric Disease Priority Review Voucher, is taken twice daily in the form of capsules and may cost US$650,000 per year, making it prohibitive for the vast majority of families. It is unclear how it will be covered by health insurance in the United States. Common side effects of the drug include "nausea, vomiting, diarrhea, infections, decreased appetite, and fatigue". Other treatment options have focused on reducing complications (such as cardiovascular disease) with coronary artery bypass surgery and low-dose acetylsalicylic acid. Growth hormone treatment has been attempted. The use of Morpholinos has also been attempted in mice and cell cultures in order to reduce progerin production. Antisense Morpholino oligonucleotides specifically directed against the mutated exon 11–exon 12 junction in the mutated pre-mRNAs were used. A type of anticancer drug, the farnesyltransferase inhibitors (FTIs), has been proposed, but their use has been mostly limited to animal models. A Phase II clinical trial using the FTI lonafarnib began in May 2007. In studies on the cells another anti-cancer drug, rapamycin, caused removal of progerin from the nuclear membrane through autophagy.

==== Pomegranate juice ==== Pomegranate juice inhibits the action of the drug metabolizing enzymes CYP2C9 and CYP3A4. As of 2014, the currently available literature does not appear to indicate a clinically relevant impact of pomegranate juice on drugs that are metabolized by CYP2C9 and CYP3A4.

== Overdose == Overdosing of up to 80 times the usual therapeutic dose has been described. Expected symptoms include severe hypotension (low blood pressure) and reflex tachycardia. Bradycardia (slow heartbeat) can also occur due to blockage of calcium channels in the atrioventricular node of the heart. There is no treatment besides monitoring blood pressure and heart function. Dialysis is likely ineffective because most of the lercanidipine is bound to blood plasma proteins and lipid membranes of cells.

Sources: en.wikipedia.org

Further detail

To reduce the effects of the testosterone flare at the initiation of GnRH agonist therapy in men Androgen-dependent skin and hair conditions such as acne, seborrhea, excessive hair growth, and scalp hair loss in women as well as high testosterone levels due to polycystic ovary syndrome (PCOS) in women, at 25 to 50 mg/day generally in combination with a birth control pill Feminizing hormone therapy for transgender women usually at 50 mg/day in combination with an estrogen. Peripheral precocious puberty in boys at 12.5 to 100 mg/day in combination with an aromatase inhibitor like anastrozole, especially for familial male-limited precocious puberty (testotoxicosis) Overly long-lasting erections in men at 50 mg per week to 50 mg every other day The medication has been suggested for but has uncertain effectiveness in the following indication:

== History == Asparagine was first isolated in 1806 in a crystalline form by French chemists Louis Nicolas Vauquelin and Pierre Jean Robiquet (then a young assistant). It was isolated from asparagus juice, in which it is abundant, hence the chosen name. It was the first amino acid to be isolated. Three years later, in 1809, Pierre Jean Robiquet identified a substance from liquorice root with properties which he qualified as very similar to those of asparagine, and which Plisson identified in 1828 as asparagine itself. The determination of asparagine's structure required decades of research. The empirical formula for asparagine was first determined in 1833 by the French chemists Antoine François Boutron Charlard and Théophile-Jules Pelouze; in the same year, the German chemist Justus Liebig provided a more accurate formula. In 1846 the Italian chemist Raffaele Piria treated asparagine with nitrous acid, which removed the molecule's amine (–NH2) groups and transformed asparagine into malic acid. This revealed the molecule's fundamental structure: a chain of four carbon atoms. Piria thought that asparagine was a diamide of malic acid; however, in 1862 the German chemist Hermann Kolbe showed that this surmise was wrong; instead, Kolbe concluded that asparagine was an amide of an amine of succinic acid. In 1886, the Italian chemist Arnaldo Piutti (1857–1928) discovered a mirror image or "enantiomer" of the natural form of asparagine, which shared many of asparagine's properties, but which also differed from it.

Hyphenated techniques LC–MS (liquid chromatography–mass spectrometry) GC–MS (gas chromatography–mass spectrometry) LC–DAD (liquid chromatography–diode array detection) CE–MS (capillary electrophoresis–mass spectrometry) Chromatographic methods HPLC (high performance liquid chromatography) GC (gas chromatography) UPLC (ultra performance liquid chromatography) Supercritical fluid chromatography Electrophoresis Preparative native polyacrylamide gel electrophoresis Ligand binding assays Dual polarisation interferometry ELISA (Enzyme-linked immunosorbent assay) MIA (magnetic immunoassay) RIA (radioimmunoassay) Mass spectrometry Nuclear magnetic resonance The most frequently used techniques are: liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) for 'small' molecules and enzyme-linked immunosorbent assay (ELISA) for macromolecules.

Of the ten top-up players, only two (James Kelly and Matt Dea) remained with the club beyond the 2016 season: Kelly played one further season before retiring, and Dea played two more seasons before being delisted.

He made a conclusion that "a natural food such as milk must therefore contain, besides these known principal ingredients, small quantities of unknown substances essential to life." However, his conclusions were rejected by his advisor, Gustav von Bunge. A similar result by Cornelis Adrianus Pekelharing appeared in Dutch medical journal Nederlands Tijdschrift voor Geneeskunde in 1905, but it was not widely reported. In East Asia, where polished white rice was the common staple food of the middle class, beriberi resulting from lack of vitamin B1 was endemic. In 1884, Takaki Kanehiro, a British-trained medical doctor of the Imperial Japanese Navy, observed that beriberi was endemic among low-ranking crew who often ate nothing but rice, but not among officers who consumed a Western-style diet. With the support of the Japanese navy, he experimented using crews of two battleships; one crew was fed only white rice, while the other was fed a diet of meat, fish, barley, rice, and beans. The group that ate only white rice documented 161 crew members with beriberi and 25 deaths, while the latter group had only 14 cases of beriberi and no deaths. This convinced Takaki and the Japanese Navy that diet was the cause of beriberi, but they mistakenly believed that sufficient amounts of protein prevented it. That diseases could result from some dietary deficiencies was further investigated by Christiaan Eijkman, who in 1897 discovered that feeding unpolished rice instead of the polished variety to chickens helped to prevent a kind of polyneuritis that was the equivalent of beriberi.

Sources: en.wikipedia.org

Frequently asked questions

Ipamorelin 与 GHRP-6 有什么不同?

两者都是 GHS-R1a 激动剂,但 ipamorelin 在研究中显示出更高的生长激素释放选择性。早期资料显示它对皮质醇、催乳素与食欲的刺激弱于 GHRP-6。这些差异是相对程度,而非绝对区分。

Ipamorelin 是已批准药物吗?

公开资料中它主要以研究用肽的形式出现,未获主要监管机构批准用于治疗。可得材料通常标注仅供研究使用。任何临床用途的宣称都缺少监管依据。

为什么它的序列含有非天然氨基酸?

序列中的 Aib 与 D-2-Nal 等非天然残基可提高对肽酶的抵抗能力,并影响受体结合的构象。这类修饰在合成肽设计中较为常见。它们也使常规氨基酸分析需要额外步骤才能确认序列。

Aib 残基起什么作用?

Aib 即 α-氨基异丁酸,是一种非蛋白质源氨基酸,其侧链为两个甲基。它在肽链中倾向于诱导螺旋构象并限制骨架的柔性。这种刚性被认为有助于抵抗蛋白酶切割。

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