The short version of 非天然氨基酸 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-26 and is reviewed periodically as new material appears.
Published animal and early human work describes growth hormone release that is separated from comparable rises in adrenocorticotropic hormone and cortisol. Prolactin changes are reported as small in the same studies. Selectivity is attributed to binding at the ghrelin receptor and to the downstream signaling that follows, rather than to differences in how quickly the peptide is cleared. Authors commonly label the compound selective rather than potent, because the same mass produces a smaller growth hormone response than some older secretagogues tested in parallel. Whether that profile holds across species and routes of administration remains an open question.
Human data remain limited and come mainly from small, short-term studies conducted decades ago. The peptide has not received approval as a medicine from major regulators, so current availability is largely as a research chemical. Reported effects on growth hormone pulsatility, appetite, and body composition should be read as preliminary, since few independent groups have replicated the original findings. Analytical characterization of research-grade material varies between suppliers, which complicates comparison across studies. Regulatory status also differs by country, and some jurisdictions classify it as a prescription-only or otherwise restricted item.
Most published work on ipamorelin comes from rodent studies and small early-phase human trials. Subcutaneous and intravenous routes have been used, while oral delivery is limited by poor absorption and rapid breakdown in the gut. The reported plasma half-life is short, on the order of two hours, and varies with species and assay method. Whether chronic use produces meaningful clinical benefit remains unresolved, and long-term safety data in humans are sparse. No major regulatory agency has approved the compound as a therapeutic drug.
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, incorporating two non-natural residues that resist enzymatic breakdown. Researchers at Novo Nordisk described the compound in the 1990s while searching for agents that release growth hormone with fewer side effects than earlier secretagogues. The molecule acts as an agonist at the ghrelin receptor, also called GHS-R1a, which is expressed in the pituitary and in several peripheral tissues.
Selectivity distinguishes ipamorelin from first-generation secretagogues such as GHRP-6. At doses that reliably raise growth hormone, it shows little stimulation of adrenocorticotropic hormone or cortisol release in animal models, and it does not markedly raise prolactin or appetite. Binding at GHS-R1a on pituitary somatotrophs triggers calcium influx and pulsatile growth hormone secretion. Because the compound mimics the natural ghrelin signal, the release pattern tends to follow the body's own rhythm rather than producing a sustained elevation.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Value for the free base |
| Molar mass | 711.9 g/mol | Calculated from the formula |
| Appearance | White to off-white powder | Typical lyophilized form |
| Mechanism class | Ghrelin receptor agonist | Also described as a secretagogue |
| Half-life | About 2 hours | Reported for human circulation |
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。
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.
At the receptor level, ipamorelin binds GHS-R1a and triggers signaling through Gq-coupled pathways. Activation leads to calcium release and downstream effects in pituitary somatotroph cells. These events promote the release of growth hormone into circulation. The response depends on the presence of the receptor and on the physiological state of the animal or tissue studied. Because the receptor is also found in other tissues, effects beyond the pituitary have been examined in laboratory models, though the extent of those effects remains an area of ongoing study.
In the 1980s, Wächtershäuser and Karl Popper postulated the iron–sulfur world hypothesis for the evolution of pre-biotic chemical pathways. It traces today's biochemistry to primordial reactions which synthesize organic building blocks from gases. Wächtershäuser systems have a built-in source of energy: iron sulfides such as pyrite. The energy released by oxidising these metal sulfides can support synthesis of organic molecules. Such systems may have evolved into autocatalytic sets constituting self-replicating, metabolically active entities predating modern life forms. Experiments with sulfides in an aqueous environment at 100 °C produced a small yield of dipeptides (0.4% to 12.4%) and a smaller yield of tripeptides (0.10%). However, under the same conditions, dipeptides were quickly broken down. Several models postulate a primitive metabolism, allowing RNA replication to emerge later. The centrality of the Krebs cycle (citric acid cycle) to energy production in aerobic organisms, and in drawing in carbon dioxide and hydrogen ions in biosynthesis of complex organic chemicals, suggests that it was one of the first parts of the metabolism to evolve. Concordantly, geochemists Szostak and Kate Adamala demonstrated that non-enzymatic RNA replication in primitive protocells is only possible in the presence of weak cation chelators like citric acid. This provides further evidence for the central role of citric acid in primordial metabolism.
{\displaystyle {\begin{aligned}y:\ &\rho \left({\partial _{t}u_{y}}+u_{x}{\partial _{x}u_{y}}+u_{y}{\partial _{y}u_{y}}+u_{z}{\partial _{z}u_{y}}\right)\\&\quad =-{\partial _{y}p}+\mu \left({\partial _{x}^{2}u_{y}}+{\partial _{y}^{2}u_{y}}+{\partial _{z}^{2}u_{y}}\right)+{\frac {1}{3}}\mu \ \partial _{y}\left({\partial _{x}u_{x}}+{\partial _{y}u_{y}}+{\partial _{z}u_{z}}\right)+\rho g_{y}\\\end{aligned}}}
Gambia: Diplomat Serign Modou Njie called on international law to be respected "without exceptions". Ghana: Foreign Minister Samuel Okudzeto Ablakwa spoke against America's actions, stating the strikes were colonial and imperialist in nature, stating they had "no place" in the current world order. Kenya: The nation did not release their own statement, instead opting to back the African Union's statement of concern of the action, stressing the territorial integrity and self-determination of Venezuelans. Liberia: Minister of Foreign Affairs Sara Beysolow Nyanti stated that action should be taken at the United Nations Security Council to further discuss the strikes. Mali: Minister of Foreign Affairs Abdoulaye Diop condemned the strikes, specifically naming those on military and civilian targets. Namibia: The Ministry of International Relations and Trade stated that the strikes had violated Venezuela's sovereignty and international law, further calling for a meeting of the United Nations Security Council to sort out the matter. The decision by Namibia, a nation which traditionality voiced anti-imperialism, to not explicitly condemn the strikes was pointed out as a change in their traditional rhetoric by Deutsche Welle. Niger: Minister of Forign Affairs Yaou Sangaré Bakary stated the situation constituted a threat to peace and stability on the South American continent.
== Medicinal use == Arnebia densiflora has been investigated for its wound healing abilities. Arnebia densiflora is one of the five species of Boraginaceae family grown in Turkey. Several species of Boraginaceous plants are used as folk medicine in Turkey and eastern Mediterranean countries. The pigmented root of Arnebia densiflora, known locally as 'Eyilik', is added to olive oil and applied on open wounds and cuts in Anatolia. In Malatya, roots of Arnebia densiflora are dipped in butter. After removing the root pieces the butter is mixed with beeswax to prepare an ointment for open wounds. Roots of Arnebia densiflora are also used as a natural-dye to color Anatolian carpets. The medicinal effect might have to do with the high naphthoquinone content in the roots barks.
The two substrates of this enzyme are cis-1,2-dihydrocatechol and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are catechol, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is cis-1,2-dihydrobenzene-1,2-diol:NAD+ oxidoreductase. Other names in common use include cis-benzene glycol dehydrogenase, cis-1,2-dihydrocyclohexa-3,5-diene (nicotinamide adenine, and dinucleotide) oxidoreductase. This enzyme participates in 4 metabolic pathways: gamma-hexachlorocyclohexane degradation, toluene and xylene degradation, naphthalene and anthracene degradation, and styrene degradation.
Sources: en.wikipedia.org
The Polish People's Republic (Polska Rzeczpospolita Ludowa) was established under the rule of the communist Polish United Workers' Party (PZPR). The name change from the Polish Republic was not officially adopted, however, until the proclamation of the Constitution of the Polish People's Republic in 1952. The ruling PZPR was formed by the forced amalgamation in December 1948 of the communist Polish Workers' Party (PPR) and the historically non-communist Polish Socialist Party (PPS). The PPR chief had been its wartime leader Władysław Gomułka, who in 1947 declared a "Polish road to socialism" as intended to curb, rather than eradicate, capitalist elements. In 1948 he was overruled, removed and imprisoned by Stalinist authorities. The PPS, re-established in 1944 by its left wing, had since been allied with the communists. The ruling communists, who in post-war Poland preferred to use the term "socialism" instead of "communism" to identify their ideological basis,[f] needed to include the socialist junior partner to broaden their appeal, claim greater legitimacy and eliminate competition on the political Left. The socialists, who were losing their organization, were subjected to political pressure, ideological cleansing and purges in order to become suitable for unification on the terms of the PPR. The leading pro-communist leaders of the socialists were the prime ministers Edward Osóbka-Morawski and Józef Cyrankiewicz. During the most oppressive phase of the Stalinist period (1948–1953), terror was justified in Poland as necessary to eliminate reactionary subversion.
== Isolation == Veratridine has been isolated from the seeds of Schoenocaulon officinale and from the rhizomes of Veratrum album. Like the other steroidal alkaloids found in these plants and similar ones in the Melanthiaceae family, it is present as part of a glycosidal combination, bonded to carbohydrate moieties. Early isolation methods relied on formation of the nitrate salt and then precipitation of the insoluble sulfate form. Accounts of these efforts date back to 1878, but the first true purification of veratridine is the one carried out in 1953 by Kupchan et al. This, and later purification procedures, begin with veratrine, a mixture of the alkaloids present in the Veratrum plants, primarily containing cevadine and veratridine. The nitrate salt is formed by dissolving the veratrine in 1% sulfuric acid over ice and precipitating with sodium nitrate. After resuspending in water over ice, the solution is brought to pH 8.5 with aqueous NaOH and then pH 10 with aqueous ammonia, forming another precipitate which is extracted with ether and then with chloroform. The ether and chloroform fractions are combined and dried. The dried residue is dissolved in sulfuric acid and the sulfate salt of veratridine is precipitated by dropwise addition of a solution of ammonium sulfate. Finally, the free base form is generated with ammonium hydroxide.
A study assessed urinary levels of pregnanediol glucuronide, the major metabolite of progesterone in urine, and found that although circulating progesterone levels and urinary levels of pregnanediol glucuronide increased after treatment with transdermal progesterone, the levels of both nonetheless remained in the range of the follicular phase and hence were very low. A case report found that the 5α-reductase inhibitor finasteride did not increase the circulating progesterone levels or urinary pregnanediol glucuronide levels produced by transdermal progesterone. Likewise, a study found that the 5α-reductase inhibitor dutasteride resulted in only slightly higher progesterone levels with transdermal progesterone. Finally, 5α-reductase is also a major enzyme involved in the metabolism of testosterone, yet transdermal testosterone is approved for androgen replacement therapy and is very effective in raising testosterone levels. In terms of elimination, a study that investigated the pharmacokinetics of transdermal progesterone using either a hydrophilic-, lipophilic-, or emulsion-type base found that in all three cases the elimination half-life was in the range of 30 to 40 hours.
=== 1 July === The SAF intercepted RSF drones in Merowe and Al-Dabbah. The RSF and the SPLM-N (al-Hilu) announced the creation in Nyala of a governing alliance headed by Hemedti, with SPLM-N leader Abdelaziz al-Hilu as his deputy.
In medicine, Murphy's sign (also known as Sweeney’s sign) is a maneuver during a physical examination as part of the abdominal examination. It is useful for differentiating pain in the right upper quadrant. Typically, it is positive in cholecystitis, but negative in choledocholithiasis, pyelonephritis, and ascending cholangitis.
Sources: en.wikipedia.org
It has not been approved as a therapeutic by major regulators, and the human trial record is small and dated. Material available today is mostly sold as a research chemical for laboratory use. Approval and restriction status varies by country.
It binds the ghrelin receptor, known as the growth hormone secretagogue receptor type 1a. Activation of that receptor triggers signaling that leads to growth hormone release. Selectivity for growth hormone over cortisol and prolactin is the property most often cited for this compound.
Published estimates place the circulating half-life at roughly two hours in humans. Clearance involves peptidase activity and renal handling. Because the peptide is short-lived, release patterns after administration are usually described as pulsatile rather than sustained.
The peptide is Aib-His-D-2-Nal-D-Phe-Lys-NH2. Two of its residues are non-natural, which slows enzymatic degradation. The C-terminal amide is common among bioactive peptides.