This is a working overview of circadian rhythm, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-09-10 and is reviewed periodically as new material appears.
Storage recommendations for SR9009 reference material typically specify a freezer at -20 °C or lower, with protection from moisture and light. Repeated freeze-thaw cycles can degrade small molecules and introduce variability. Stock solutions in dimethyl sulfoxide are often aliquoted to avoid repeated handling. Stability studies may examine degradation under heat, humidity, and light exposure. The compound's thiophene and nitro groups can participate in reactions that alter analytical signals over time, so such changes affect quantitative results.
Quality control for research materials includes identity confirmation by nuclear magnetic resonance and purity assessment by high-performance liquid chromatography. Mass spectrometry provides molecular weight confirmation and can detect related impurities. Purchasers should request a certificate of analysis that lists lot-specific data. Online products advertised for human use often lack such documentation. Distinguishing legitimate research material from mislabeled or contaminated samples is a recurring challenge in independent testing, and independent laboratories may use orthogonal methods to verify identity.
Identity and purity testing for SR9009 commonly uses liquid chromatography coupled with tandem mass spectrometry. This method separates the compound from matrix components and detects it by mass-to-charge transitions, providing sensitive and specific confirmation. Nuclear magnetic resonance spectroscopy can support structural identification, while high-performance liquid chromatography with ultraviolet detection may estimate purity. Because online products labeled as SR9009 may contain other substances or no active compound at all, independent verification is important in research settings. Certificates of analysis are useful but not a substitute for in-house testing.
Laboratory samples of SR9009 are typically supplied as a white to off-white powder. The compound dissolves readily in organic solvents such as dimethyl sulfoxide and ethanol, while its solubility in water is low. Because of this solubility profile, researchers often prepare concentrated stock solutions in an organic solvent before diluting them into aqueous assay buffers. Light exposure, moisture, and repeated freeze-thaw cycles can degrade many small molecules, so handling procedures usually aim to minimize these factors. Purity is commonly checked before use.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or lower | Desiccated and protected from light |
| Common analytical method | LC-MS/MS | Detects parent drug and metabolites |
| Solubility class | Lipophilic; soluble in organic solvents | Low aqueous solubility |
| Molecular weight | 437.94 g/mol | Calculated from reported formula |
| Synonyms | SR9009; REV-ERB agonist | Code name used in scientific literature |
Pharmacokinetic data for SR9009 are limited in published literature. Some reports indicate low oral bioavailability and rapid clearance in animals, which complicates interpretation of exposure and effect. Researchers often use injected routes in preclinical work to achieve measurable systemic levels. Analytical studies rely on mass spectrometry to detect the parent compound and its metabolites. Questions about tissue distribution, active metabolites, and long-term consequences remain open. Species differences in metabolism can affect observed half-life and target engagement.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. These receptors help regulate circadian rhythms and metabolic gene expression. In laboratory experiments, SR9009 binds these receptors and alters transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. It is not a naturally occurring compound and has no approved therapeutic use. Research interest stems from its ability to modify energy metabolism in cells and animal models.
Identity and purity of SR9009 samples are usually checked with chromatographic and spectrometric methods. High-performance liquid chromatography can separate the compound from related impurities, while mass spectrometry provides molecular mass confirmation. Nuclear magnetic resonance spectroscopy may be used for structural verification in research settings. No single method proves biological activity, and certificates of analysis should be reviewed alongside raw data. Independent testing is often needed because online products vary widely.
SR9009 stability depends on temperature, moisture, light, and solvent. Solid material is generally kept cool and dry, while solutions may require protection from repeated warming and cooling. Degradation can appear as color changes, precipitate, or new chromatographic peaks. Researchers should follow supplier instructions and their own stability data. Long-term storage conditions for human use have not been established because the compound lacks approved clinical formulation.
SR9009 is supplied as a solid research chemical, often in milligram quantities. Laboratories typically weigh it in a controlled environment because fine powders can disperse. Stock solutions are commonly prepared in dimethyl sulfoxide and stored in small aliquots to reduce freeze-thaw cycles. Personal protective equipment and chemical fume hoods are standard when handling unknown or potent compounds. These practices address laboratory safety rather than human use.
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.
=== Sandwich debate === There is an ongoing debate about whether a hot dog, fully assembled in its bun with condiments, fits the description of a sandwich. Merriam-Webster has stated that a hot dog is indeed a sandwich. In 2015, the National Hot Dog and Sausage Council (NHDSC), on the other hand, declared that a hot dog is not a sandwich. Hot dog eating champions Joey Chestnut and Takeru Kobayashi agree with the NHDSC, as does Nathan's Famous, the host of a significant hot dog eating contest. United States Supreme Court justice Ruth Bader Ginsburg also weighed in on the matter, stating that a hot dog might be categorized as a sandwich, but ultimately it comes down to the definition of a sandwich. She went on to acknowledge that a hot dog bun is a single roll that is not sliced all the way through, and in that way is similar to a submarine sandwich.
Gly + [Glu(-Cys)]n+1-Gly Thus, the two substrates of this enzyme are glutathione and [Glu(-Cys)]n-Gly, whereas its two products are Gly and [Glu(-Cys)]n+1-Gly. This enzyme belongs to the family of transferases, specifically the aminoacyltransferases. The systematic name of this enzyme class is glutathione:poly(4-glutamyl-cysteinyl)glycine 4-glutamylcysteinyltransferase. Other names in common use include phytochelatin synthase, and gamma-glutamylcysteine dipeptidyl transpeptidase.
=== Structure-activity relationships === In a virtual screen for novel agonists, a structure-activity relationship was determined from the most potent compounds ('hits') identified. These hits contained a pyrazolo[3,4-d]pyrimidine core (shown in figure 5), which is important for potency toward the 5-HT2C receptors. Compounds with maximum potency featured two substituents linked to the core structure. The first substituent is a piperazine ring, containing a small hydrophobic group; the second substituent is a phenyl part containing a halogen- and/or oxygen-containing side chain (electronegative groups), see derivatives 1 and 2 in figure 5. Addition of aromatic groups to the piperazine ring reduces potency (derivative 4 in figure 5) and the absence of the piperazine ring or substitution with other aliphatic- or cyclic groups reduces potency as well (derivatives 5 and 6 in figure 5).
Most species are generalist predators, eating microalgae, sponges, bivalves, snails and other small animals. The crown-of-thorns starfish consumes coral polyps, while other species are detritivores, feeding on decomposing organic material and faecal matter. A few are suspension feeders, gathering in phytoplankton; Henricia and Echinaster often feed with sponges, taking advantage of the water current they produce. Various species can absorb organic nutrients from the surrounding water, and this may form a significant portion of their diet. The processes of feeding and capture may be aided by special parts; Pisaster brevispinus, the short-spined pisaster from the West Coast of America, can use a set of specialized tube feet to dig itself deep into the soft substrate to extract prey (usually clams). Grasping the shellfish, the starfish slowly pries open the prey's shell, overcoming the clam's adductor muscle, and inserts its everted stomach into the crack to digest the soft tissues. The gap between the clam's valves need only be a fraction of a millimetre wide for the stomach to gain entry.
=== Filming === Filming began in March 2019 with Glen Winter directing the pilot. Christopher Manley and Scott Peck were directors of photography on the series. Filming occurred throughout the Atlanta metropolitan area, including: Marietta, Virginia–Highland, Duluth, Lithia Springs, Dallas, Marietta Square, West End, Westlake High School, the Atlanta Center for Medical Research, Campbell Middle School, Paulding County, Smyrna, Arbor Place Mall, Vinings, Mableton, and Douglas County High School. Walter Garcia served as the series' stunt coordinator and second-unit director. He was hired to help Stargirl's staff "have a personality and be alive when she fights with it". The series continued to film in Atlanta for the second season, with filming beginning by October 28, 2020.
Sources: en.wikipedia.org
=== Launch === The chain was announced in July 2023. The first CosMc's store opened on December 7, 2023 in the village of Bolingbrook, Illinois. The opening day saw a large queue of customers in the drive-thru which was the only way to order through the restaurant. CNN reported that the Bolingbrook location saw more than twice the number of visits for a typical McDonald's location, citing data from Placer.ai, with the customer base largely skewed to those aged 22–29. At the time of launch, McDonald's planned to have ten operational stores, including nine in Texas by 2024. McDonald's CEO Chris Kempczinski said that the company would evaluate the ten stores as a "limited test”, adding "Let's not get too excited." In its first month, the store reportedly had twice the traffic of a regular McDonald's. A new app and rewards program, CosMc’s Club, along with mobile ordering, was introduced in May 2024. In early 2025, the company announced it would close three of its larger format locations and open two smaller locations in Texas.
== Pharmacology == Experiments on former addicts indicated it was quite addictive and in high doses, compared to other opioids, may have increased abuse potential in former and current opioid addicts. While some effort was first suggested for drafting of a resolution urging governments to stop manufacture and use of ketobemidone, this result was not in agreement with clinical observations, and another study in 1958 did not find it more addictive than morphine. That study noticed that while for morphine the dose for euphoria is the same as that for analgesia, for ketobemidone the analgesic dose was well below the euphoric dose. Thus, even compared to morphine, ketobemidone may be much more effective without causing significant euphoria and thus having a lower risk of addiction under the supervision of a qualified clinician. Ketobemidone is mostly used in the Scandinavian countries, with Denmark topping the statistics. Analgesia after 5-10 mg orally or 5–7.5 mg intravenously lasts 3–5 hours. Ketobemidone is also available in preparations with a spasmolytic, which can improve the analgesia.
Prior to this, there had been failed synthesis attempts in 1986–87 at the Joint Institute for Nuclear Research in Dubna (then in the Soviet Union) and in 1990 at the GSI. A 1995 attempt at the Lawrence Berkeley National Laboratory resulted in signs suggesting but not pointing conclusively at the discovery of a new isotope 267Ds formed in the bombardment of 209Bi with 59Co, and a similarly inconclusive 1994 attempt at the JINR showed signs of 273Ds being produced from 244Pu and 34S. Each team proposed its own name for element 110: the American team proposed hahnium after Otto Hahn in an attempt to resolve the controversy of naming element 105 (which they had long been suggesting this name for), the Russian team proposed becquerelium after Henri Becquerel, and the German team proposed darmstadtium after Darmstadt, the location of their institute. The IUPAC/IUPAP Joint Working Party (JWP) recognised the GSI team as discoverers in their 2001 report, giving them the right to suggest a name for the element.
== Function == LRP5 acts as a co-receptor with LRP6 and the Frizzled protein family members for transducing signals by Wnt proteins through the canonical Wnt pathway. This protein plays a key role in skeletal homeostasis.
Part C states, which were chief commissioners' provinces and some princely states, each governed by a chief commissioner appointed by the President of India. The ten Part C states were Ajmer, Bhopal, Bilaspur, Coorg, Delhi, Himachal Pradesh, Cutch, Manipur, Tripura and Vindhya Pradesh. One Part D state (Andaman and Nicobar Islands) administered by a lieutenant governor appointed by the central government. After the States Reorganisation Act, 1956, Part C and Part D states were combined into a single category of "Union territory". Due to various other reorganisations, only 6 union territories remained:
Sources: en.wikipedia.org
== Adverse effects == Besides being a hepatocarcinogen, safrole exhibits further adverse effects in that it will induce the formation of hepatic lipid hydroperoxides. Safrole also inhibits the defensive function of neutrophils against bacteria. In addition to the inhibition of the defensive function of neutrophils, it has also been discovered that safrole interferes with the formation of superoxides by neutrophils. Furthermore, safrole oxide, a metabolite of safrole, has a negative effect on the central nervous system. Safrole oxide inhibits the expression of integrin β4/SOD, leading to apoptosis of the nerve cells.
=== FIFA fan festivals === FIFA staged fan festivals in cities across the host nations, featuring matches on giant screens and live entertainment. Among the fan fest locations were Liberty State Park in Jersey City, the National World War I Museum and Memorial in Kansas City, Missouri, Fairmount Park in Philadelphia, Fort York and The Bentway in Toronto, Centennial Olympic Park in Atlanta, East Downtown Houston, and the Pacific National Exhibition in Vancouver, Canada.
Essay about the effect and demonstrations by Jearl Walker (PDF) Site with high-speed video, pictures and explanation of film-boiling by Heiner Linke at the University of Oregon, USA "Scientists make water run uphill" by BBC News about using the Leidenfrost effect for cooling of computer chips. "Uphill Water" – ABC Catalyst story "Leidenfrost Maze" – University of Bath undergraduate students Carmen Cheng and Matthew Guy "When Water Flows Uphill" – Science Friday with Univ. of Bath professor Kei Takashina Jeffrey, Colin (March 10, 2015). "Engine running on frozen carbon dioxide may power mission to Mars". Gizmag. Retrieved 10 March 2015. Carolyn Embach, ResearchGate: English translation of Johan Gottlob Leidenfrost, De aquae communes nonnullis qualitatibus tractatus, Duisburg on Rhine, 1756. (Carolyn S. E. Wares aka Carolyn Embach, translator, 1964)
It is used for the treatment of anxiety and has similar effectiveness compared to diazepam. Ketazolam also appears to produce reduced levels of side effects such as sedation compared with diazepam and the side effects when they occur tend to be milder. Ketazolam is also an effective antispasmodic drug and is used for the treatment of spasticity.
Sources: en.wikipedia.org
Liquid chromatography-tandem mass spectrometry is a common approach. It can detect the parent compound and its metabolites in biological matrices.
Research samples are typically kept frozen, desiccated, and protected from light. Stock solutions are often aliquoted to reduce freeze-thaw cycles.
High-performance liquid chromatography and nuclear magnetic resonance are standard for purity and identity. Mass spectrometry confirms molecular weight.
Research-grade SR9009 is typically stored frozen at about minus twenty degrees Celsius, protected from light and moisture. Stock solutions are often kept in aliquots to avoid repeated freeze-thaw cycles. Specific storage conditions should follow the supplier's documentation.