somatotroph raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
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.
对 ipamorelin 的常规表征以反相高效液相色谱测定纯度，检测波长多设为 214 nm，因为肽键在该波长有较强吸收。身份确认通常借助电喷雾电离质谱或串联质谱，将实测分子量与理论值逐项比对。序列层面可用肽图分析或氨基酸分析进一步验证。这些手段组合起来，可以分别覆盖纯度、身份与序列三个不同层次的信息。
杂质谱一般包含缺失序列片段、差向异构体、氧化产物以及残留溶剂或反离子，其中组氨酸与芳香残基的氧化常被重点关注。反相色谱中这类杂质往往紧邻主峰洗脱，因此方法需要足够的分离度并经过系统适用性验证。纯度百分比的解读依赖于检测波长与梯度条件，不同实验室公布的数字不宜直接横向比较。参考标准品有助于跨批次对照，但其自身赋值同样需要可追溯来源。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Includes two non-natural residues |
| Molecular weight | About 711.9 g/mol | Confirmed by mass spectrometry |
| Appearance | White to off-white powder | Typical lyophilized form |
| Receptor target | GHS-R1a | Ghrelin receptor agonist |
| Plasma half-life | Roughly 2 hours | Varies by species and assay |
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。
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。
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.
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.
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.
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.
A number of studies measuring anabolic steroid use in high school athletes found that out of all 12th grade students, 6.6 percent of them had used anabolic steroids at some point in their high school careers or were approached and counseled to use them. Of those students who acknowledged doping with anabolic–androgenic steroids, well over half participated in school-sponsored athletics, including football, wrestling, track and field, and baseball. A second study showed 6.3 percent of high school student Football players admitted to current or former AAS use. At the collegiate level, surveys show that AAS use among athletes range from 5 percent to 20 percent and continues to rise. The study found that skin changes were an early marker of steroid use in young athletes, and underscored the important role that dermatologists could play in the early detection and intervention in these athletes.
Because β-alanine dipeptides are not incorporated into proteins, they can be stored at relatively high concentrations. Occurring at 17–25 mmol/kg (dry muscle), carnosine (β-alanyl-L-histidine) is an important intramuscular buffer, constituting 10-20% of the total buffering capacity in type I and II muscle fibres. In carnosine, the pKa of the imidazolium group is 6.83, which is ideal for buffering.
The power law model is used to display the behavior of Newtonian and non-Newtonian fluids and measures shear stress as a function of strain rate. The relationship between shear stress, strain rate and the velocity gradient for the power law model are:
Sources: en.wikipedia.org
He pleaded no contest on November 25, and was given a year's probation, a $1,000 fine, and ordered to carry out 80 hours of community service. In 2007, Marshall told Fox News that WWE knew of the abuse, but worked to keep her from revealing that Austin had hit her as it would cost the company millions of dollars. Austin responded to the incident in 2003 through WWE Raw Magazine, citing his regret over their relationship breaking down and stating his love for Marshall. He also ridiculed allegations that the incident was alcohol-related. He filed for divorce from Marshall on July 22, 2002, which was finalized on February 5, 2003. In March 2003, during the hours leading up to WrestleMania XIX, Austin was rushed to the hospital for twitchiness and a high heart rate. In 2003, Austin denied allegations that he was an alcoholic, stating that wrestling fans had mistaken his character's excessive consumption of beer as a real-life trait of his and insisting that he drinks responsibly. In March 2004, he was accused of assaulting his then-girlfriend Tess Broussard during a dispute at his home in San Antonio, Texas, according to a police report. No arrests were made and no charges were filed in the case. In 2007, the Wrestling Observer newsletter reported that Austin had legally changed his name to Steve Austin. In late 2009, Austin married his fourth wife, Kristin Feres. In 2014, Austin voiced support for same-sex marriage on his podcast. Also in 2014, Austin released his first beer, Broken Skull IPA, with El Segundo Brewing Company in California.
== See also == List of pre-Columbian cultures Domesticated plants of Mesoamerica Agriculture in Mesoamerica Mesoamerican cuisine Mesoamerican diet and subsistence Mesoamerican architecture Indigenous music of North America Painting in the Americas before European colonization Mesoamerican chronology History portal North America portal Central America portal South America portal
=== EC 2.3.1: Transferring groups other than amino-acyl groups === EC 2.3.1.1: amino-acid N-acetyltransferase EC 2.3.1.2: imidazole N-acetyltransferase EC 2.3.1.3: glucosamine N-acetyltransferase EC 2.3.1.4: glucosamine-phosphate N-acetyltransferase EC 2.3.1.5: arylamine N-acetyltransferase EC 2.3.1.6: choline O-acetyltransferase EC 2.3.1.7: carnitine O-acetyltransferase EC 2.3.1.8: phosphate acetyltransferase EC 2.3.1.9: acetyl-CoA C-acetyltransferase EC 2.3.1.10: hydrogen-sulfide S-acetyltransferase EC 2.3.1.11: thioethanolamine S-acetyltransferase EC 2.3.1.12: dihydrolipoyllysine-residue acetyltransferase EC 2.3.1.13: glycine N-acyltransferase EC 2.3.1.14: glutamine N-phenylacetyltransferase EC 2.3.1.15: glycerol-3-phosphate O-acyltransferase EC 2.3.1.16: acetyl-CoA C-acyltransferase EC 2.3.1.17: aspartate N-acetyltransferase EC 2.3.1.18: galactoside O-acetyltransferase EC 2.3.1.19: phosphate butyryltransferase EC 2.3.1.20: diacylglycerol O-acyltransferase EC 2.3.1.21: carnitine O-palmitoyltransferase EC 2.3.1.22: 2-acylglycerol O-acyltransferase EC 2.3.1.23: 1-acylglycerophosphocholine O-acyltransferase EC 2.3.1.24: sphingosine N-acyltransferase EC 2.3.1.25: plasmalogen synthase EC 2.3.1.26: sterol O-acyltransferase EC 2.3.1.27: cortisol O-acetyltransferase EC 2.3.1.28: chloramphenicol O-acetyltransferase EC 2.3.1.29: glycine C-acetyltransferase EC 2.3.1.30: serine O-acetyltransferase EC 2.3.1.31: homoserine O-acetyltransferase EC 2.3.1.32: lysine N-acetyltransferase EC 2.3.1.33: histidine N-acetyltransferase EC 2.3.1.34: D-tryptophan N-acetyltransferase EC 2.3.1.35: glutamate N-acetyltransferase EC 2.3.1.36: D-amino-acid N-acetyltransferase EC 2.3.1.37: 5-aminolevulinate synthase EC 2.3.1.38: [acyl-carrier-protein] S-acetyltransferase EC 2.3.1.39: [acyl-carrier-protein] S-malonyltransferase EC 2.3.1.40: acyl-[acyl-carrier-protein]—phospholipid O-acyltransferase EC 2.3.1.41: β-ketoacyl-[acyl-carrier-protein] synthase I EC 2.3.1.42: glycerone-phosphate O-acyltransferase EC 2.3.1.43: phosphatidylcholine—sterol O-acyltransferase EC 2.3.1.44: N-acetylneuraminate 4-O-acetyltransferase EC 2.3.1.45: N-acetylneuraminate 7-O(or 9-O)-acetyltransferase EC 2.3.1.46: homoserine O-succinyltransferase EC 2.3.1.47: 8-amino-7-oxononanoate synthase EC 2.3.1.48: histone acetyltransferase EC 2.3.1.49: deacetyl-(citrate-(pro-3S)-lyase) S-acetyltransferase EC 2.3.1.50: serine C-palmitoyltransferase EC 2.3.1.51: 1-acylglycerol-3-phosphate O-acyltransferase EC 2.3.1.52: 2-acylglycerol-3-phosphate O-acyltransferase EC 2.3.1.53: phenylalanine N-acetyltransferase EC 2.3.1.54: formate C-acetyltransferase EC 2.3.1.55: identical to EC 2.3.1.82 EC 2.3.1.56: aromatic-hydroxylamine O-acetyltransferase EC 2.3.1.57: diamine N-acetyltransferase EC 2.3.1.58: 2,3-diaminopropionate N-oxalyltransferase EC 2.3.1.59: gentamicin 2′-N-acetyltransferase EC 2.3.1.60: gentamicin 3′-N-acetyltransferase EC 2.3.1.61: dihydrolipoyllysine-residue succinyltransferase EC 2.3.1.62: 2-acylglycerophosphocholine O-acyltransferase EC 2.3.1.63: 1-alkylglycerophosphocholine O-acyltransferase EC 2.3.1.64: agmatine N4-coumaroyltransferase EC 2.3.1.65: bile acid-CoA:amino acid N-acyltransferase EC 2.3.1.66: leucine N-acetyltransferase EC 2.3.1.67: 1-alkylglycerophosphocholine O-acetyltransferase EC 2.3.1.68: glutamine N-acyltransferase EC 2.3.1.69: monoterpenol O-acetyltransferase EC 2.3.1.70: deleted EC 2.3.1.71: glycine N-benzoyltransferase EC 2.3.1.72: indoleacetylglucose—inositol O-acyltransferase EC 2.3.1.73: diacylglycerol—sterol O-acyltransferase EC 2.3.1.74: chalcone synthase EC 2.3.1.75: long-chain-alcohol O-fatty-acyltransferase EC 2.3.1.76: retinol O-fatty-acyltransferase EC 2.3.1.77: triacylglycerol—sterol O-acyltransferase EC 2.3.1.78: heparan-α-glucosaminide N-acetyltransferase EC 2.3.1.79: maltose O-acetyltransferase EC 2.3.1.80: cysteine-S-conjugate N-acetyltransferase EC 2.3.1.81: aminoglycoside 3-N-acetyltransferase EC 2.3.1.82: aminoglycoside 6′-N-acetyltransferase EC 2.3.1.83: phosphatidylcholine—dolichol O-acyltransferase EC 2.3.1.84: alcohol O-acetyltransferase EC 2.3.1.85: fatty-acid synthase system EC 2.3.1.86: fatty-acyl-CoA synthase system EC 2.3.1.87: aralkylamine N-acetyltransferase EC 2.3.1.88: Now covered by EC 2.3.1.254, EC 2.3.1.255, EC 2.3.1.256, EC 2.3.1.257, EC 2.3.1.258 and EC 2.3.1.259 EC 2.3.1.89: tetrahydrodipicolinate N-acetyltransferase EC 2.3.1.90: β-glucogallin O-galloyltransferase EC 2.3.1.91: sinapoylglucose—choline O-sinapoyltransferase EC 2.3.1.92: sinapoylglucose—malate O-sinapoyltransferase EC 2.3.1.93: 13-hydroxylupinine O-tigloyltransferase EC 2.3.1.94: 6-deoxyerythronolide-B synthase EC 2.3.1.95: trihydroxystilbene synthase EC 2.3.1.96: glycoprotein N-palmitoyltransferase EC 2.3.1.97: glycylpeptide N-tetradecanoyltransferase EC 2.3.1.98: chlorogenate—glucarate O-hydroxycinnamoyltransferase EC 2.3.1.99: quinate O-hydroxycinnamoyltransferase EC 2.3.1.100: [myelin-proteolipid] O-palmitoyltransferase EC 2.3.1.101: formylmethanofuran—tetrahydromethanopterin N-formyltransferase EC 2.3.1.102: N6-hydroxylysine O-acetyltransferase EC 2.3.1.103: sinapoylglucose—sinapoylglucose O-sinapoyltransferase EC 2.3.1.104: The activity is covered by EC 2.3.1.25 EC 2.3.1.105: alkylglycerophosphate 2-O-acetyltransferase EC 2.3.1.106: tartronate O-hydroxycinnamoyltransferase EC 2.3.1.107: deacetylvindoline O-acetyltransferase EC 2.3.1.108: α-tubulin N-acetyltransferase EC 2.3.1.109: arginine N-succinyltransferase EC 2.3.1.110: tyramine N-feruloyltransferase EC 2.3.1.111: mycocerosate synthase EC 2.3.1.112: D-tryptophan N-malonyltransferase EC 2.3.1.113: anthranilate N-malonyltransferase EC 2.3.1.114: 3,4-dichloroaniline N-malonyltransferase EC 2.3.1.115: isoflavone-7-O-β-glucoside 6′′-O-malonyltransferase EC 2.3.1.116: flavonol-3-O-β-glucoside O-malonyltransferase EC 2.3.1.117: 2,3,4,5-tetrahydropyridine-2,6-dicarboxylate N-succinyltransferase EC 2.3.1.118: N-hydroxyarylamine O-acetyltransferase EC 2.3.1.119: Now covered by EC 2.3.1.199, EC 1.1.1.330, EC 4.2.1.134 and EC 1.3.1.93 EC 2.3.1.120: The reaction is due to EC 2.3.1.74 EC 2.3.1.121: 1-alkenylglycerophosphoethanolamine O-acyltransferase EC 2.3.1.122: trehalose O-mycolyltransferase EC 2.3.1.123: dolichol O-acyltransferase EC 2.3.1.124: Already listed as EC 2.3.1.20 EC 2.3.1.125: 1-alkyl-2-acetylglycerol O-acyltransferase EC 2.3.1.126: isocitrate O-dihydroxycinnamoyltransferase EC 2.3.1.127: ornithine N-benzoyltransferase EC 2.3.1.128: now classified as EC 2.3.1.266 and EC 2.3.1.267 EC 2.3.1.129: acyl-[acyl-carrier-protein]—UDP-N-acetylglucosamine O-acyltransferase EC 2.3.1.130: galactarate O-hydroxycinnamoyltransferase EC 2.3.1.131: glucarate O-hydroxycinnamoyltransferase EC 2.3.1.132: glucarolactone O-hydroxycinnamoyltransferase EC 2.3.1.133: shikimate O-hydroxycinnamoyltransferase EC 2.3.1.134: galactolipid O-acyltransferase EC 2.3.1.135: phosphatidylcholine—retinol O-acyltransferase EC 2.3.1.136: polysialic-acid O-acetyltransferase EC 2.3.1.137: carnitine O-octanoyltransferase EC 2.3.1.138: putrescine N-hydroxycinnamoyltransferase EC 2.3.1.139: ecdysone O-acyltransferase EC 2.3.1.140: rosmarinate synthase EC 2.3.1.141: galactosylacylglycerol O-acyltransferase EC 2.3.1.142: glycoprotein O-fatty-acyltransferase EC 2.3.1.143: β-glucogallin—tetrakisgalloylglucose O-galloyltransferase EC 2.3.1.144: anthranilate N-benzoyltransferase EC 2.3.1.145: piperidine N-piperoyltransferase EC 2.3.1.146: pinosylvin synthase EC 2.3.1.147: glycerophospholipid arachidonoyl-transferase (CoA-independent) EC 2.3.1.148: glycerophospholipid acyltransferase (CoA-dependent) EC 2.3.1.149: platelet-activating factor acetyltransferase EC 2.3.1.150: salutaridinol 7-O-acetyltransferase EC 2.3.1.151: 2,3′,4,6-tetrahydroxybenzophenone synthase EC 2.3.1.152: alcohol O-cinnamoyltransferase EC 2.3.1.153: anthocyanin 5-(6′′′-hydroxycinnamoyltransferase) EC 2.3.1.154: Now EC 2.3.1.176 EC 2.3.1.155: acetyl-CoA C-myristoyltransferase EC 2.3.1.156: phloroisovalerophenone synthase EC 2.3.1.157: glucosamine-1-phosphate N-acetyltransferase EC 2.3.1.158: phospholipid:diacylglycerol acyltransferase EC 2.3.1.159: acridone synthase EC 2.3.1.160: vinorine synthase EC 2.3.1.161: lovastatin nonaketide synthase EC 2.3.1.162: taxadien-5α-ol O-acetyltransferase EC 2.3.1.163: 10-hydroxytaxane O-acetyltransferase EC 2.3.1.164: isopenicillin-N N-acyltransferase EC 2.3.1.165: 6-methylsalicylic acid synthase EC 2.3.1.166: 2α-hydroxytaxane 2-O-benzoyltransferase EC 2.3.1.167: 10-deacetylbaccatin III 10-O-acetyltransferase EC 2.3.1.168: dihydrolipoyllysine-residue (2-methylpropanoyl)transferase EC 2.3.1.169: CO-methylating acetyl-CoA synthase EC 2.3.1.170: 6′-deoxychalcone synthase EC 2.3.1.171: anthocyanin 6′′-O-malonyltransferase EC 2.3.1.172: anthocyanin 5-O-glucoside 6′′′-O-malonyltransferase EC 2.3.1.173: flavonol-3-O-triglucoside O-coumaroyltransferase EC 2.3.1.174: 3-oxoadipyl-CoA thiolase EC 2.3.1.175: deacetylcephalosporin-C acetyltransferase EC 2.3.1.176: propanoyl-CoA C-acyltransferase EC 2.3.1.177: 3,5-dihydroxybiphenyl synthase EC 2.3.1.178: diaminobutyrate acetyltransferase EC 2.3.1.179: β-ketoacyl-[acyl-carrier-protein] synthase II EC 2.3.1.180: β-ketoacyl-[acyl-carrier-protein] synthase III EC 2.3.1.181: lipoyl(octanoyl) transferase EC 2.3.1.182: Now covered by EC 2.3.3.21 EC 2.3.1.183: phosphinothricin acetyltransferase EC 2.3.1.184: acyl-homoserine-lactone synthase EC 2.3.1.185: tropine acyltransferase EC 2.3.1.186: pseudotropine acyltransferase EC 2.3.1.187: acetyl-S-ACP:malonate ACP transferase EC 2.3.1.188: ω-hydroxypalmitate O-feruloyl transferase EC 2.3.1.189: mycothiol synthase EC 2.3.1.190: acetoin dehydrogenase EC 2.3.1.191: UDP-3-O-(3-hydroxyacyl)glucosamine N-acyltransferase EC 2.3.1.192: glycine N-phenylacetyltransferase EC 2.3.1.193: tRNAMetcytidine acetyltransferase EC 2.3.1.194: acetoacetyl-CoA synthase EC 2.3.1.195: (Z)-3-hexen-1-ol acetyltransferase EC 2.3.1.196: benzyl alcohol O-benzoyltransferase EC 2.3.1.197: dTDP-3-amino-3,6-dideoxy-α-D-galactopyranose 3-N-acetyltransferase EC 2.3.1.198: glycerol-3-phosphate 2-O-acyltransferase EC 2.3.1.199: very-long-chain 3-oxoacyl-CoA synthase EC 2.3.1.200: lipoyl amidotransferase EC 2.3.1.201: UDP-2-acetamido-3-amino-2,3-dideoxy-glucuronate N-acetyltransferase EC 2.3.1.202: UDP-4-amino-4,6-dideoxy-N-acetyl-β-L-altrosamine N-acetyltransferase EC 2.3.1.203: UDP-N-acetylbacillosamine N-acetyltransferase EC 2.3.1.204: octanoyl-[GcvH]:protein N-octanoyltransferase EC 2.3.1.205: fumigaclavine B O-acetyltransferase EC 2.3.1.206: 3,5,7-trioxododecanoyl-CoA synthase EC 2.3.1.207: β-ketodecanoyl-[acyl-carrier-protein] synthase EC 2.3.1.208: 4-hydroxycoumarin synthase EC 2.3.1.209: dTDP-4-amino-4,6-dideoxy-D-glucose acyltransferase EC 2.3.1.210: dTDP-4-amino-4,6-dideoxy-D-galactose acyltransferase EC 2.3.1.211: bisdemethoxycurcumin synthase EC 2.3.1.212: benzalacetone synthase EC 2.3.1.213: cyanidin 3-O-(6-O-glucosyl-2-O-xylosylgalactoside) 6′′′-O-hydroxycinnamoyltransferase EC 2.3.1.214: pelargonidin 3-O-(6-caffeoylglucoside) 5-O-(6-O-malonylglucoside) 4′′′-malonyltransferase EC 2.3.1.215: anthocyanin 3-O-glucoside 6-O-hydroxycinnamoyltransferase EC 2.3.1.216: 5,7-dihydroxy-2-methylchromone synthase EC 2.3.1.217: curcumin synthase EC 2.3.1.218: phenylpropanoylacetyl-CoA synthase EC 2.3.1.219: demethoxycurcumin synthase EC 2.3.1.220: 2,4,6-trihydroxybenzophenone synthase EC 2.3.1.221: noranthrone synthase EC 2.3.1.222: phosphate propanoyltransferase EC 2.3.1.223: 3-oxo-5,6-didehydrosuberyl-CoA thiolase EC 2.3.1.224: acetyl-CoA-benzylalcohol acetyltransferase EC 2.3.1.225: protein S-acyltransferase EC 2.3.1.226: carboxymethylproline synthase EC 2.3.1.227: GDP-perosamine N-acetyltransferase EC 2.3.1.228: isovaleryl-homoserine lactone synthase EC 2.3.1.229: 4-coumaroyl-homoserine lactone synthase EC 2.3.1.230: 2-heptyl-4(1H)-quinolone synthase EC 2.3.1.231: tRNAPhe {7-[3-amino-3-(methoxycarbonyl)propyl]wyosine37 -N}-methoxycarbonyltransferase EC 2.3.1.232: methanol O-anthraniloyltransferase EC 2.3.1.233: 1,3,6,8-tetrahydroxynaphthalene synthase EC 2.3.1.234: N6-L-threonylcarbamoyladenine synthase EC 2.3.1.235: tetracenomycin F2 synthase EC 2.3.1.236: 5-methylnaphthoic acid synthase EC 2.3.1.237: neocarzinostatin naphthoate synthase EC 2.3.1.238: monacolin J acid methylbutanoate transferase EC 2.3.1.239: 10-deoxymethynolide synthase EC 2.3.1.240: narbonolide synthase EC 2.3.1.241: Kdo2-lipid IVA lauroyltransferase EC 2.3.1.242: Kdo2-lipid IVA palmitoleoyltransferase EC 2.3.1.243: lauroyl-Kdo2-lipid IVA myristoyltransferase EC 2.3.1.244: 2-methylbutanoate polyketide synthase EC 2.3.1.245: 3-hydroxy-5-phosphooxypentane-2,4-dione thiolase EC 2.3.1.246: 3,5-dihydroxyphenylacetyl-CoA synthase EC 2.3.1.247: 3-keto-5-aminohexanoate cleavage enzyme EC 2.3.1.248: spermidine disinapoyl transferase EC 2.3.1.249: spermidine dicoumaroyl transferase EC 2.3.1.250: [Wnt protein] O-palmitoleoyl transferase EC 2.3.1.251: lipid IVA palmitoyltransferase EC 2.3.1.252: mycolipanoate synthase EC 2.3.1.253: phloroglucinol synthase EC 2.3.1.254: N-terminal methionine Nα-acetyltransferase NatB EC 2.3.1.255: N-terminal amino-acid Nα-acetyltransferase NatA EC 2.3.1.256: N-terminal methionine Nα-acetyltransferase NatC EC 2.3.1.257: N-terminal L-serine Nα-acetyltransferase NatD EC 2.3.1.258: N-terminal methionine Nα-acetyltransferase NatE EC 2.3.1.259: N-terminal methionine Nα-acetyltransferase NatF EC 2.3.1.260: tetracycline polyketide synthase EC 2.3.1.261: (4-hydroxyphenyl)alkanoate synthase EC 2.3.1.262: anthraniloyl-CoA anthraniloyltransferase EC 2.3.1.263: 2-amino-4-oxopentanoate thiolase EC 2.3.1.264: β-lysine N6-acetyltransferase EC 2.3.1.265: phosphatidylinositol dimannoside acyltransferase EC 2.3.1.266: [ribosomal protein S18]-alanine N-acetyltransferase EC 2.3.1.267: [ribosomal protein S5]-alanine N-acetyltransferase EC 2.3.1.268: ethanol O-acetyltransferase EC 2.3.1.269: apolipoprotein N-acyltransferase EC 2.3.1.270: lyso-ornithine lipid O-acyltransferase EC 2.3.1.271: L-glutamate-5-semialdehyde N-acetyltransferase EC 2.3.1.272: 2-acetylphloroglucinol acetyltransferase EC 2.3.1.273: diglucosylglycerate octanoyltransferase EC 2.3.1.274: phosphate acyltransferase EC 2.3.1.275: acyl phosphate:glycerol-3-phosphate acyltransferase EC 2.3.1.276: galactosamine-1-phosphate N-acetyltransferase EC 2.3.1.277: 2-oxo-3-(phosphooxy)propyl 3-oxoalkanoate synthase EC 2.3.1.278: mycolipenoyl-CoA—2-(long-chain-fatty acyl)-trehalose mycolipenoyltransferase EC 2.3.1.279: long-chain-acyl-CoA—trehalose acyltransferase EC 2.3.1.280: (aminoalkyl)phosphonate N-acetyltransferase EC 2.3.1.281: 5-hydroxydodecatetraenal polyketide synthase EC 2.3.1.282: phenolphthiocerol/phthiocerol/phthiodiolone dimycocerosyl transferase EC 2.3.1.283: 2′-acyl-2-O-sulfo-trehalose (hydroxy)phthioceranyltransferase EC 2.3.1.284: 3′-(hydroxy)phthioceranyl-2′-palmitoyl(stearoyl)-2-O-sulfo-trehalose (hydroxy)phthioceranyltransferase EC 2.3.1.285: (13S,14R)-1,13-dihydroxy-N-methylcanadine 13-O-acetyltransferase EC 2.3.1.286: protein acetyllysine N-acetyltransferase EC 2.3.1.287: phthioceranic/hydroxyphthioceranic acid synthase EC 2.3.1.288: 2-O-sulfo trehalose long-chain-acyltransferase EC 2.3.1.289: aureothin polyketide synthase system EC 2.3.1.290: spectinabilin polyketide synthase system EC 2.3.1.291: sphingoid base N-palmitoyltransferase EC 2.3.1.292: (phenol)carboxyphthiodiolenone synthase EC 2.3.1.293: meromycolic acid 3-oxoacyl-(acyl carrier protein) synthase I EC 2.3.1.294: meromycolic acid 3-oxoacyl-(acyl carrier protein) synthase II EC 2.3.1.295: mycoketide-CoA synthase EC 2.3.1.296: ω-hydroxyceramide transacylase EC 2.3.1.297: very-long-chain ceramide synthase EC 2.3.1.298: ultra-long-chain ceramide synthase EC 2.3.1.299: sphingoid base N-stearoyltransferase EC 2.3.1.300: branched-chain β-ketoacyl-[acyl-carrier-protein] synthase EC 2.3.1.301: mycobacterial β-ketoacyl-[acyl carrier protein] synthase III EC 2.3.1.302: hydroxycinnamoyl-CoA:5-hydroxyanthranilate N-hydroxycinnamoyltransferase EC 2.3.1.303: α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und 2IV-O-acetyltransferase EC 2.3.1.304: poly[(S)-3-hydroxyalkanoate] polymerase
Thus these two experiments are used to build so called spin systems, that is build a list of resonances of the chemical shift of the peptide proton, the alpha protons and all the protons from each residue's sidechain. Which chemical shifts corresponds to which nuclei in the spin system is determined by the conventional correlation spectroscopy connectivities and the fact that different types of protons have characteristic chemical shifts. To connect the different spinsystems in a sequential order, the nuclear Overhauser effect spectroscopy experiment has to be used. Because this experiment transfers magnetization through space, it will show crosspeaks for all protons that are close in space regardless of whether they are in the same spin system or not. The neighbouring residues are inherently close in space, so the assignments can be made by the peaks in the NOESY with other spin systems. One important problem using homonuclear nuclear magnetic resonance is overlap between peaks. This occurs when different protons have the same or very similar chemical shifts. This problem becomes greater as the protein becomes larger, so homonuclear nuclear magnetic resonance is usually restricted to small proteins or peptides.
Sources: en.wikipedia.org
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.
It binds the same ghrelin receptor but with greater selectivity in functional assays. Preclinical work reports less cortisol and prolactin stimulation at growth-hormone-releasing doses. Those differences are relative, not absolute, and depend on dose and model.
No major regulatory authority has approved it for human therapeutic use. It is sold as a research chemical for laboratory investigation. Clinical status varies by country and is subject to change.
肽键在 214 nm 附近有较强吸收，适合检测缺少芳香侧链的短肽。该波长的基线受流动相组成与梯度影响较大。因此流动相与梯度条件需要固定并完整记录。