The short version of HPLC-MS fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-23. Anything still debated is marked as such rather than presented as settled.
Laboratory identification of SR9009 typically relies on chromatographic separation coupled to mass spectrometry, often with ultraviolet detection as a secondary check. Nuclear magnetic resonance spectroscopy can confirm molecular structure when a reference standard is available. Because many suppliers sell the compound as a research chemical, independent identity testing is important for experimental reproducibility. A single retention time is not sufficient proof of identity, especially when related compounds may be present. Purity assessments usually report a percentage based on area normalization.
SR9009 is generally described as poorly soluble in water and more soluble in organic solvents such as dimethyl sulfoxide and ethanol. Stock solutions are commonly prepared in an organic solvent before dilution into an aqueous buffer or vehicle. Precipitation can occur if the organic fraction is reduced too quickly or if the final concentration exceeds the compound's solubility limit. Sonication or gentle warming may aid dissolution in some protocols, but excessive heat can promote degradation. Container material and pH can also influence observed solubility.
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.
In rodent studies, SR9009 has been reported to increase mitochondrial content in skeletal muscle and improve exercise endurance under some conditions. These findings led to popular descriptions such as an exercise mimetic, although that term oversimplifies the biology. Effects vary by dose, timing, tissue, and model. The compound's influence on circadian pathways means that time of administration can matter in experiments. Whether similar metabolic changes occur in humans remains largely unexplored in controlled published trials.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Visual inspection is not sufficient for identity. |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water; stock solutions use organic solvent. |
| Storage | -20°C, desiccated, protected from light | Limits hydrolysis and photodegradation. |
| Analytical method | HPLC-UV/MS | Used for identity and purity assessment. |
| Synonyms | SR9009, Stenabolic | Naming varies by supplier. |
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.
By the end of the 20th century in North America, few new doctors went directly from medical school into independent, unsupervised medical practice, and more state and provincial governments began requiring one or more years of postgraduate training for medical licensure. Residencies are traditionally hospital-based, and in the middle of the 20th century, residents would often live (or "reside") in hospital-supplied housing. "Call" (night duty in the hospital) was sometimes as frequent as every second or third night for up to three years. Pay was minimal beyond room, board, and laundry services. It was assumed that most young men and women training as physicians had few obligations outside of medical training at that stage of their careers. The first year of practical patient-care-oriented training after medical school has long been termed "internship". Even as late as the middle of the twentieth century, most physicians went into primary care practice after a year of internship. Residencies were separate from internship, often served at different hospitals, and only a minority of physicians did residencies. In the United States, the Libby Zion case, which led to the Libby Zion Law, garnered attention in 1984, shed light on the demanding work hours imposed on medical residents. Responding to this concern, the Association of American Medical Colleges released a position statement in 1988, recommending a cap of 80 work hours per week for residents.
== Measurement == BNP and NT-proBNP are measured by immunoassay. Immunoassays use antibodies that bind to a specific part of the molecule to test for. Antibodies are only able to determine the amount of peptides matching their epitope fragments. They largely cannot differentiate between a cleaved part and the uncleaved precursor. For example, a BNP antibody is likely to cross-react to proBNP but not NT-proBNP.
Fish can also be made into floss (魚鬆; yú sōng), though initial stewing is not required due to the low collagen and elastin content of fish meat. Rabbit and duck floss can also be found in China. In Muslim-majority Indonesia and Malaysia, beef or chicken floss is the most popular variant, commonly called abon in Indonesian and serunding (also spelled serondeng) in Malay. In Malaysia, serunding is often served during Ramadan and Eid. In Nigeria, beef, goat or other meats are processed into a similar meat floss called dambu nama.
Sources: en.wikipedia.org
Haji-Sheikh, Haji-Sheikh & Naples (2026) present new cranial endocasts of Smilodon fatalis, and calculate that the range of brain endocast volumes of the studied species overlaps with the published range of brain volumes of modern lions. Evidence of utility of CT and MicroCT scans in determining the condition of tooth sockets in skulls of Smilodon fatalis from the La Brea Tar Pits, as well as in determining whether the canines of the studied specimens were correctly associated and correctly seated in tooth sockets during restoration of the skulls, is presented by Haji-Sheikh, Haji-Sheikh & Naples (2026). Schmökel, Del Chicca & Hagen Argudin Pina (2026) identify pathologies in three vertebrae of Smilodon fatalis from the La Brea Tar Pits, interpreted as consistent with the diagnosis of a spinal nerve tumor. Fernández-Jalvo et al. (2026) identify tooth marks of Smilodon on bones of Toxodon, Notiomastodon, Doedicurus, Glossotherium and Lestodon from the Pleistocene strata from the Salto de Piedra site (Argentina). A felid mandible interpreted as the most definitive fossil material of Homotherium latidens from Anatolia reported to date is described from the Burdur Basin (Turkey) by Yavuz et al. (2026). Nikolskiy et al. (2026) report the discovery of canines of Homotherium in the late Pleistocene strata from Suruktakh in the Kolyma River basin and from the Bolshoy Lyakhovsky Island (Russia), comfirming presence of members of this genus in northeastern Siberia approximately 41,500–37,500 years ago.
=== Extraction === Oil extraction is simply the removal of oil from the reservoir (oil pool). There are many methods of extracting the oil from the reservoirs for example; mechanical shaking, water-in-oil emulsion, and specialty chemicals called demulsifiers that separate the oil from water. Oil extraction is costly and often environmentally damaging. Offshore exploration and extraction of oil disturb the surrounding marine environment.
=== Detectors === Far-IR spectrometers commonly use pyroelectric detectors that respond to changes in temperature as the intensity of IR radiation falling on them varies. The sensitive elements in these detectors are either deuterated triglycine sulfate (DTGS) or lithium tantalate (LiTaO3). These detectors operate at ambient temperatures and provide adequate sensitivity for most routine applications. To achieve the best sensitivity the time for a scan is typically a few seconds. Cooled photoelectric detectors are employed for situations requiring higher sensitivity or faster response. Liquid nitrogen cooled mercury cadmium telluride (MCT) detectors are the most widely used in the mid-IR. With these detectors an interferogram can be measured in as little as 10 milliseconds. Uncooled indium gallium arsenide photodiodes or DTGS are the usual choices in near-IR systems. Very sensitive liquid-helium-cooled silicon or germanium bolometers are used in the far-IR where both sources and beamsplitters are inefficient.
The AAA proteins contain two domains, an N-terminal alpha/beta domain that binds and hydrolyzes nucleotides (a Rossmann fold) and a C-terminal alpha-helical domain. The N-terminal domain is 200-250 amino acids long and contains Walker A and Walker B motifs, and is shared in common with other P-loop NTPases, the superfamily which includes the AAA family. Most AAA proteins have additional domains that are used for oligomerization, substrate binding and/or regulation. These domains can lie N- or C-terminal to the AAA module. Some classes of AAA proteins have an N-terminal non-ATPase domain which is followed by either one or two AAA domains (D1 and D2). In some proteins with two AAA domains, both are evolutionarily well conserved (like in Cdc48/p97). In others, either the D2 domain (like in Pex1p and Pex6p) or the D1 domain (in Sec18p/NSF) is better conserved in evolution. While the classical AAA family was based on motifs, the family has been expanded using structural information and is now termed the AAA family.
Sources: en.wikipedia.org
Liquid chromatography with mass spectrometry is a common approach. Ultraviolet detection and nuclear magnetic resonance can support identification when suitable standards are available.
The solid is generally kept cold, dry, and protected from light. Solutions are often frozen in single-use aliquots to reduce repeated freeze-thaw cycles.
It indicates a material sold for laboratory study, not for human use. The label does not guarantee pharmaceutical purity, sterility, or regulatory approval.
It is a synthetic research compound that activates REV-ERB nuclear receptors. It is not an approved drug or dietary supplement. Most information comes from cell and animal studies.