This is a working overview of reference standard, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-06 and is reviewed periodically as new material appears.
Analytical identification and purity assessment often use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Liquid chromatography–tandem mass spectrometry is used to detect and quantify SR9009 in biological matrices, including urine and blood, for anti-doping or pharmacokinetic studies. Nuclear magnetic resonance spectroscopy can confirm molecular structure. Stability depends on form and storage: the solid is generally more stable than solutions, and repeated freeze–thaw cycles may degrade samples. Purity is typically reported as a percentage from a certificate of analysis.
Regulatory treatment of SR9009 varies by country and context. It is not approved as a therapeutic drug by agencies such as the United States Food and Drug Administration or the European Medicines Agency. Sports authorities list it as a prohibited substance; the World Anti-Doping Agency classifies it among hormone and metabolic modulators. Legal status for personal possession or sale differs across jurisdictions, and some countries may restrict it under analog or research chemical laws. Buyers who seek verified material often rely on independent laboratory testing because online product labels may not match contents.
In laboratory settings, SR9009 is commonly identified by its molecular structure and its interaction with REV-ERB receptors. Vendors may list it under synonyms such as Stenabolic or REV-ERB agonist, but those names do not define purity or identity. Analytical confirmation typically uses high-performance liquid chromatography with ultraviolet detection or liquid chromatography–mass spectrometry. A reference standard is needed to compare retention time and mass spectrum, because the compound can be confused with related research chemicals.
Handling practices for SR9009 focus on minimizing degradation and contamination. The solid is generally stored desiccated at or below -20 °C, protected from light and moisture. Stock solutions are often prepared in dimethyl sulfoxide or ethanol, then aliquoted to avoid repeated freeze–thaw cycles. Aqueous solubility is low, so formulations for animal studies may require cosolvents or suspending agents. Personnel should follow institutional chemical safety procedures, because toxicological data for humans are incomplete.
Regulatory status varies by country and intended use. Major drug agencies have not granted marketing authorization for SR9009 as a medicine, and it is not listed as a controlled substance in many jurisdictions. It is often sold as a research chemical, a category that may fall outside pharmaceutical manufacturing rules. Buyers should verify local laws and supplier documentation, including certificates of analysis. The lack of standardized quality controls raises concerns about identity, purity, and actual content in products marketed online.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Common supplier description |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water |
| Typical storage | −20 °C, desiccated, dark | For research samples |
| Analytical method | LC-MS/MS | Used for detection and quantification |
| Regulatory status | Prohibited in sport | WADA metabolic modulator class |
Physicochemical behavior influences handling. SR9009 is described as a solid with limited aqueous solubility, so organic solvents such as dimethyl sulfoxide or ethanol are common in research stock solutions. Aqueous dilution can produce precipitates if the organic content is too low. Light, heat, and repeated freeze-thaw cycles may affect stability. Storage recommendations usually specify a desiccated freezer environment protected from light, but exact stability data depend on the formulation and matrix.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
Handling recommendations for SR9009 in a laboratory setting include storing the solid at low temperature, protected from light and moisture. The compound is often dissolved in dimethyl sulfoxide or ethanol for experiments. Solutions should be prepared with appropriate personal protective equipment and disposed of according to local rules. Stability data for long-term storage are limited, so stock solutions are typically kept cold and used within defined periods. Records of preparation date and concentration support reproducibility.
SR9009 is not approved as a medicine by major regulatory agencies. It is commonly sold as a research chemical, a category that may fall outside customary drug approval and quality rules. In sports, the World Anti-Doping Agency lists SR9009 as a prohibited substance. Athletes who use it can face sanctions if it is detected in a sample. Legal status varies by country, and importation may be restricted. Enforcement practices differ across borders.
Detection of SR9009 in biological samples usually employs liquid chromatography coupled with tandem mass spectrometry. This method can identify the parent compound and sometimes metabolites in urine or blood. Because exposure can be low and clearance may be rapid, sample timing and limits of detection matter. Laboratories validate assays for sensitivity and specificity. Results are interpreted alongside chain-of-custody and quality-control records. Urine is the common matrix for anti-doping analysis, while blood may be used in research settings.
== Clinical significance == This ligament is an important anatomical landmark of the duodenojejunal flexure, separating the upper and lower gastrointestinal tracts. For example, bloody vomit or melena, black tarry stools, usually indicate a gastrointestinal bleed from a location in the upper gastrointestinal tract. In contrast, hematochezia, bright red blood or clots in the stool, usually indicates gastrointestinal bleeding from the lower part of the gastrointestinal tract. It is an especially important landmark to note when looking at the bowel for the presence of malrotation of the gut, a syndrome often suspected in young children when they have episodes of recurrent vomiting. Visualising a normal location of the ligament of Treitz in radiological images is critical in ruling out malrotation of the gut in a child; it is abnormally located when malrotation is present. During a Whipple's procedure, commonly used to treat pancreatic cancer by removing the pancreas, duodenum, and part of the jejunum, the ligament of Treitz is separated from the duodenum and preserved. When the remaining jejunum is anastamosed with the pylorus of the stomach, it may be passed through the ligament. Superior mesenteric artery syndrome (SMA) is an extremely rare life-threatening condition that can either be congenital and chronic, or induced and acute. SMA Syndrome is characterised by compression of the duodenum between the abdominal aorta and the superior mesenteric artery, and may—when congenital—result from a short suspensory muscle.
The energy released is about 180 kJ/mol, which is conserved when 2 ATP are generated from 2 ADP per glucose. Anaerobic bacteria and archaea use these and many other fermentative pathways, e.g., propionic acid fermentation, butyric acid fermentation, solvent fermentation, mixed acid fermentation, butanediol fermentation, Stickland fermentation, acetogenesis, or methanogenesis.
Chromatography, including gas chromatography, GC/MS, high performance liquid chromatography, and LC/MS. Spectroscopy, including UV-Vis, CD, near infrared, and FT-IR Inductively coupled plasma, including mass spectroscopic and atomic emission spectroscopic detection. mass spectrometry, including FTMS Nuclear magnetic resonance Linear accelerator Magnetic resonance imaging X-ray Crystallography Information rich detection Drugs of Abuse Testing Dissolution Testing Vacuum Pumps Leak Detection Turbo Pumping Systems Vacuum Measurement Valves and components
Sources: en.wikipedia.org
hypertonic Describing a solution containing a high concentration of dissolved solutes relative to another solution, i.e. having positive osmotic pressure, such that solvent will tend to move by osmosis across a semipermeable membrane from the solution of lower solute concentration to the solution of higher concentration until both solutions have equal concentrations. In a cell where the intracellular cytosol is hypertonic relative to the surrounding extracellular fluid (which by definition is hypotonic relative to the cytosol), the solvent (water) will flow across the plasma membrane into the cytosol, filling the cell with extra water and diluting its contents until both sides of the membrane are isotonic. Cells placed in severely hypotonic environments may be at risk of bursting due to the sudden inflow.
== Cambodian controversy (1970) == The Paris peace talks had become stalemated by late 1969, owing to the obstructionism of the South Vietnamese delegation who wanted the talks to fail. The South Vietnamese President Nguyễn Văn Thiệu did not want the United States to withdraw from Vietnam, and out of frustration with him, Kissinger decided to begin secret peace talks in Paris parallel to the official talks that the South Vietnamese were unaware of. On 21 February 1970, in a modest house in a Paris suburb, Kissinger secretly met Lê Đức Thọ, the North Vietnamese diplomat who was to become his most tenacious adversary. In 1981, Kissinger told the journalist Stanley Karnow: "I don't look back on our meetings with any great joy, yet he was a person of substance and discipline who defended the position he represented with dedication". Not until February 1971 were Rogers and Laird first informed of the parallel peace talks in Paris. Kissinger was to meet Tho three times between February–April 1970, and the North Vietnamese first sensed a softening of the American position during these talks as Kissinger slightly altered the "mutual withdrawal formula" that the Americans had previously held to. Nixon was gravely disappointed that the secret talks in Paris did not have the prompt results he wanted. Kissinger wrote in his memoirs that "historians rarely do justice to the psychological stress on a policy-maker", noting that by early 1970 Nixon was feeling very much besieged and inclined to lash out against a world he was believed was plotting his downfall.
=== Extracellular matrix === Extracellular matrix (or "ECM") is the external structural framework that cells attach to in multicellular organisms. The dermis lies below the epidermis, and these two layers are collectively known as the skin. Dermal skin is primarily a combination of fibroblasts growing in this matrix. The specific species of ECM of connective tissues often differ chemically, but collagen generally forms the bulk of the structure. Through the interaction of a cell with its extracellular matrix (transmitted through the anchoring molecules classed as integrins) there forms a continuous association between the cell interior, cell membrane and its extracellular matrix components that helps drive various cellular events in a regulated fashion. Wound healing is a localized event involving the reaction of cells to the damage sustained. The cells break down damaged ECM and replace it, generally increasing in number to react to the harm. The process is activated, though perhaps not exclusively, by cells responding to fragments of damaged ECM, and the repairs are made by reassembling the matrix by cells growing on and through it. Because of this, extracellular matrix is often considered as a 'conductor of the wound healing symphony'. In the Inflammatory phase, neutrophils and macrophages recruit and activate fibroblasts which in subsequent granulation phase migrate into the wound, laying down new collagen of the subtypes I and III. In the initial events of wound healing, collagen III predominates in the granulation tissue.
Commercial motor vehicles such as cars, vans, trucks, specialist vehicles (such as mobile construction machinery), forklifts, and trailers Private vehicles used for work purposes (the 'grey fleet') Aviation machinery such as aircraft (planes and helicopters) Ships Rail cars Non-powered assets such as generators, tanks, gear boxes, dumpsters, shipping containers, trailers, excavators, and other equipment that can't run on its own power. Fleet (vehicle) management can include a range of functions, such as vehicle leasing and financing, vehicle maintenance, licensing and compliance, supply chain management, accident management and subrogation, vehicle telematics (tracking and diagnostics), driver management, speed management, fuel management, health and safety management, and vehicle re-marketing. Fleet Management is a function which allows companies which rely on transportation in business to remove or minimize the risks associated with vehicle investment, improving efficiency, productivity and reducing their overall transportation and staff costs, providing 100% compliance with government legislation (duty of care) and many more. These functions can be dealt with by either an in-house fleet-management department or an outsourced fleet-management provider. The number of light duty vehicles registered in commercial fleets in Europe as of 2016 was 15 million, and 19.5 million in North America. Even with these record numbers of registration, light duty vehicles represent only 62% of all fleet sales.
Sources: en.wikipedia.org
foreign policy in Africa's southern subcontinent, and there was a steady flow of defence technology from Washington to Pretoria. American and Western European interest in the defence of Africa from a hypothetical, external communist invasion dissipated after it became clear that the nuclear arms race was making global conventional war increasingly less likely. Emphasis shifted towards preventing communist subversion and infiltration via proxy rather than overt Soviet aggression. American support to South Africa was predicated on the ability of South Africa to prevent wider communist insurgency from growing in the region.
multiple cloning site (MCS) Also polylinker. A locus or sequence within a plasmid vector which contains multiple unique restriction sites recognized by various restriction endonucleases, which makes it possible for scientists to target the insertion of a DNA fragment (often a gene cassette) specifically to that locus and in the desired orientation, by digesting the insert and the vector with the same endonuclease(s) and then ligating them together via compatible restriction ends, a technique known as restriction cloning. Commercial plasmids designed for cloning commonly incorporate one or more multiple cloning sites.
== History == Flupirtine was discovered and developed between the 1970s and the 1990s by Chemiewerk Homburg in Frankfurt am Main, Germany, which became Degussa Pharma Group and then through mergers, ASTA Pharma and Asta Medica. Retigabine, a bioisostere of flupirtine, was discovered as part of the same program and has a similar mechanism of action. Flupirtine was approved for the treatment of pain in 1984 in Europe under the brand name Katadolon. As of 2013 it was used in 11 member countries: Bulgaria, Estonia, Germany, Hungary, Italy, Latvia, Lithuania, Poland, Portugal, Romania and Slovak Republic. Many generics entered the European market around 2011. It was never introduced to the United States market for any indication but in 2008, Adeona Pharmaceuticals, Inc. (now called Synthetic Biologics, Inc.) obtained an option to license issued and patent pending applications relating to flupirtine's use in the treatment of ophthalmic indications, particularly retinitis pigmentosa. As of 2016 it is marketed under many brand names, including Efiret, Flupigil, Flupirtin, Flupirtina, Flupirtine, Flupizen, Fluproxy, Katadolon, Metanor, Trancolong, and Zentiva.
Autocatalytic reactions are reactions where the reaction product acts as a catalyst for its own formation. Many researchers that study proto-metabolism agree that early metabolic networks likely originated as a set of chemical reactions that form self-sustaining networks. This set of reactions is commonly referred to as an autocatalytic set. Some prebiotic chemistries focus on these autocatalytic reactions including the formose reaction, HCN oligomerization, and formamide chemistry.
{\displaystyle {\begin{aligned}\varphi :\ &\rho \left({\partial _{t}u_{\varphi }}+u_{r}{\partial _{r}u_{\varphi }}+{\frac {u_{\varphi }}{r}}{\partial _{\varphi }u_{\varphi }}+u_{z}{\partial _{z}u_{\varphi }}+{\frac {u_{r}u_{\varphi }}{r}}\right)\\&\quad =-{\frac {1}{r}}{\partial _{\varphi }p}\\&\qquad +\mu \left({\frac {1}{r}}\ \partial _{r}\left(r{\partial _{r}u_{\varphi }}\right)+{\frac {1}{r^{2}}}{\partial _{\varphi }^{2}u_{\varphi }}+{\partial _{z}^{2}u_{\varphi }}-{\frac {u_{\varphi }}{r^{2}}}+{\frac {2}{r^{2}}}{\partial _{\varphi }u_{r}}\right)\\&\qquad +{\frac {1}{3}}\mu {\frac {1}{r}}\partial _{\varphi }\left({\frac {1}{r}}{\partial _{r}\left(ru_{r}\right)}+{\frac {1}{r}}{\partial _{\varphi }u_{\varphi }}+{\partial _{z}u_{z}}\right)\\&\qquad +\rho g_{\varphi }\\[8px]\end{aligned}}}
Sources: en.wikipedia.org
Legality depends on the country and the intended use. In many places it is sold as a research chemical, but sports and medicine regulations restrict it.
Detection commonly uses liquid chromatography–tandem mass spectrometry. This method can identify the compound in urine or blood at low concentrations.
Typical guidance is −20 °C, dry, and protected from light. Solutions should be aliquoted and limited freeze–thaw cycles should be used.
Liquid chromatography–mass spectrometry is common for identity and purity checks. High-performance liquid chromatography with ultraviolet detection can also be used. Both methods require a suitable reference standard.