If you have been reading about LC-MS/MS and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-06-17. Numbers and descriptions here follow the published literature rather than marketing material.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not an approved medicine and has no established human therapeutic use. The compound appears in scientific literature as a tool for probing circadian and metabolic regulation. Online sellers often label it as a research chemical, sometimes using the nickname Stenabolic. Its chemical identity is distinct from selective androgen receptor modulators, stimulants, and peroxisome proliferator-activated receptor delta agonists. Researchers use it mainly in cell and animal experiments.
At the molecular level, SR9009 binds REV-ERBα and REV-ERBβ and alters their repressive activity on target genes. These nuclear receptors help regulate the circadian clock, lipid synthesis, glucose metabolism, and inflammatory pathways. By changing transcription, the compound can shift the timing or magnitude of downstream metabolic processes in model systems. It does not act through androgen receptors or adenosine receptors, which distinguishes it from several substances sold for athletic performance. Whether the same transcriptional changes occur in humans at tolerable exposures remains an open question because controlled human studies are lacking.
Analytical identification of SR9009 typically relies on liquid chromatography coupled with tandem mass spectrometry. In biological samples, researchers first separate the compound from matrix components using protein precipitation, liquid-liquid extraction, or solid-phase extraction. High-performance liquid chromatography with ultraviolet detection and nuclear magnetic resonance spectroscopy can support structural confirmation of reference materials. Because SR9009 is a small, relatively lipophilic molecule, reverse-phase columns and acidic mobile phases are common. Laboratories often include isotope-labeled internal standards to improve quantification and to correct for ion suppression.
Stability depends on physical form, temperature, light exposure, and solvent. Solid SR9009 is generally stored cold and dry, with protection from light to limit degradation. Dimethyl sulfoxide stocks are common for laboratory work, but repeated freeze-thaw cycles can reduce compound integrity. Aqueous solutions may be less stable than organic stocks, and the ethyl ester in the structure can be susceptible to hydrolysis under certain conditions. Researchers typically validate storage conditions and recheck purity before quantitative experiments, especially when using archived material.
Regulatory treatment of SR9009 varies by country and region. It is not approved as a pharmaceutical, and several jurisdictions restrict its sale for human consumption. Some authorities classify it as a research chemical, a prescription-only substance, or a prohibited performance-enhancing agent in sport. Purchasers may encounter certificates of analysis, but these documents do not guarantee identity, purity, or legality. In research settings, institutional safety reviews and controlled procurement help ensure that materials are handled under appropriate oversight. The absence of harmonized rules means that legal status can change and requires verification.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C20H24ClN3O4S | Derived from published structure. |
| Molecular weight | 437.94 g/mol | Calculated value. |
| Appearance | White to off-white solid | Typical for purified research samples. |
| Solubility | DMSO, ethanol; low in water | Class: poorly water-soluble. |
| Typical storage | -20 °C, desiccated, protected from light | Limits degradation. |
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not a steroid, peptide, or natural hormone. In scientific literature, it appears under the code SR9009 and in non-scientific contexts as Stenabolic. The compound was identified through chemical screening efforts aimed at targeting circadian clock components. Its status remains investigational, and no regulatory agency has approved it as a human medicine.
REV-ERB proteins help regulate daily cycles in gene expression, including genes tied to lipid and glucose metabolism. SR9009 binds these receptors and alters their activity in cell and animal experiments. Consequences observed in rodents include changes in skeletal muscle oxidative capacity, blood lipid levels, and exercise performance. The precise chain from receptor occupancy to whole-body effects is still an active area of study. Human responses cannot be assumed from rodent data.
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.
For long-term storage, SR9009 is typically kept as a solid at low temperature, protected from moisture and light. Desiccated conditions limit hydrolysis, while opaque containers reduce photochemical breakdown. Solutions are less stable than solids and are often stored frozen in aliquots to avoid repeated freeze-thaw cycles. Stability data are not standardized across all suppliers, so users should rely on certificate-of-analysis information when available. Degradation may appear as color change, precipitate, or decreased chromatographic purity.
Because REV-ERB receptors are core clock components, SR9009 has been examined for effects on daily rhythms as well as metabolism. Research has explored whether the compound can shift or reinforce circadian gene expression in tissues such as liver and muscle. Some studies report improved metabolic markers in obese or diabetic mice, while others show context-dependent responses. Questions remain about which effects are direct, which are secondary to timing, and how they might differ across species.
SR9009 is a synthetic small molecule studied as an agonist of REV-ERB nuclear receptors. REV-ERB alpha and REV-ERB beta help regulate circadian rhythms and metabolic gene expression. In laboratory research, SR9009 has been used to probe how these receptors affect skeletal muscle, liver, and adipose tissue. The compound was identified in academic drug-discovery work and is often described in scientific literature by its chemical name and research code. It is not an approved medicine, and human clinical data remain limited or absent.
SR9009 binds REV-ERB receptors and alters their repressive activity on target genes. This action can change transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. In rodent studies, treated animals have shown changes in muscle oxidative capacity and exercise performance, though effects vary by dose, duration, and model. The precise molecular steps connecting receptor binding to whole-body outcomes are still an active area of investigation. Findings in animals do not automatically translate to humans.
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.
Nurses affiliated with the New Zealand Nurses Organisation in Auckland and Whangārei commence industrial action to protest staff shortages. A member of the New Zealand Defence Force pleads guilty before a court-martial to attempted espionage on behalf of a foreign country, in the first espionage conviction in New Zealand. He is sentenced to two years' imprisonment on 20 August. 19 August: The Interislander and Bluebridge cancel several ferry sailings due to strong swells in the Cook Strait. Foreign Minister Winston Peters recalls Trevor Mallard as New Zealand ambassador to Ireland, designating Angela Hassan-Sharp as his successor. Employees of media company Stuff vote to take strike action to protest their employer's plan to split their collective bargaining agreement. 20 August: Secondary school teachers affiliated with the Post Primary Teachers' Association went on strike for a day after rejecting the Government's one percent pay rise offer. The New Zealand Cabinet agrees to draft legislation banning greyhound racing in New Zealand. 21 August: Defence Minister Judith Collins and Foreign Minister Winston Peters announce that the Government will purchase two new Airbus A321XLR jets and five MH-60R Seahawks for the New Zealand Defence Force. Carter Holt Harvey proposes closing its Eves Valley Sawmill in the Tasman District, potentially affecting 142 jobs. Airliner Jetstar admits to 20 charges of breaching the Fair Trading Act 1986 by misleading customers about compensation.
Potential applications can be envisioned for detecing mercury in fish. Some mercury sensors (MS) are complexes of fluorescein and napthofluorescein. The MS1 probe increases its emission upon binding of Hg(II), while maintaining great affinity for mercury over other heavy metal ions. The S3 sensor is based on a BODIPY complex which undergoes a significant increase in fluorescence upon the binding of Hg(II). MF1 uses a soft thioether chelator for Hg(II) bound to a fluorescein-like xanthenone reporter. It has good contrast upon binding mercury and good selectivity. MF1 is sensitive enough that it has been proposed to be used to test fish for toxic levels of mercury.
Salyut 1, the first space station, was launched by the Soviets on April 19, 1971. Three days later, the Soyuz 10 crew attempted to dock with it, but failed to achieve a secure enough connection to safely enter the station. The Soyuz 11 crew of Vladislav Volkov, Georgi Dobrovolski and Viktor Patsayev successfully docked on June 7, and completed a then record 22-day stay. The crew became the second in-flight space fatality during their reentry on June 30, when they were asphyxiated due to the spacecraft's cabin becoming depressurized, shortly after undocking. The disaster was blamed on a faulty cabin pressure valve, that allowed the air to vent into space. The crew was not wearing pressure suits and had no chance of survival once the leak occurred. To prevent a recurrence of the Soyuz 11 tragedy, Soviet engineers redesigned the Soyuz spacecraft and mandated that cosmonauts wear Sokol pressure suits during launch and landing, a requirement still in place today. The United States launched a single orbital workstation, Skylab, on May 14, 1973. It was launched using a leftover Saturn-5 rocket from the Apollo programme. Skylab weighed 169,950 pounds (77,090 kg), was 58 feet (18 m) long by 21.7 feet (6.6 m) in diameter, and had a habitable volume of over 10,000 cubic feet (280 m3). Skylab was damaged during the ascent to orbit, losing one of its solar panels and a meteoroid thermal shield. Subsequent crewed missions repaired the station, and conducted valuable research.
Sources: en.wikipedia.org
==== Ovarian production ==== Progesterone is the major progestogen produced by the corpus luteum of the ovary in all mammalian species. Luteal cells possess the necessary enzymes to convert cholesterol to pregnenolone, which is subsequently converted into progesterone. Progesterone is highest in the diestrus phase of the estrous cycle.
Due to the mutiny of the Military Police of Espírito Santo State in which the agents demanded the correction of the remuneration for inflation, along with retroactive payments, criminal gangs and drug traffickers took advantage of the situation and a crime wave of violence, carjacking and looting spread across Espírito Santo, with most public services and businesses being closed. The Espírito Santo state government called in assistance from the National Public Security Force and the Brazilian Armed Forces to restore law and order in Vitória and other cities until military policemen began to return to their duties after two weeks of strike action. By 25 February, all military policemen in Espírito Santo had ended their strikes. At least 215 people were killed in the violence.
=== Cations and carbonylates === The synthesis of ionic carbonyl complexes is possible by oxidation or reduction of the neutral complexes. Anionic metal carbonylates can be obtained for example by reduction of dinuclear complexes with sodium. A familiar example is the sodium salt of iron tetracarbonylate (Na2Fe(CO)4, Collman's reagent), which is used in organic synthesis. The cationic hexacarbonyl salts of manganese, technetium and rhenium can be prepared from the carbonyl halides under carbon monoxide pressure by reaction with a Lewis acid.
Sources: en.wikipedia.org
There are two major classifications of 2D liquid chromatography. These include: Comprehensive 2D liquid chromatography (LCxLC) and Heart-cutting 2D liquid chromatography (LC-LC). In comprehensive 2D-LC, all the peaks from a column elution are fully sampled, but it has been deemed unnecessary to transfer the entire sample from the first to the second column. A portion of the sample is sent to waste while the rest is sent to the sampling valve. In heart-cutting 2D-LC specific peaks are targeted with only a small portion of the peak being injected onto a second column. Heart-cutting 2D-LC has proven to be quite useful for sample analysis of substances that are not very complex provided they have similar retention behavior. Compared to comprehensive 2D-LC, heart-cutting 2D-LC provides an effective technique with much less system setup and a much lower operating cost. Multiple heart-cutting (mLC-LC) may be utilized to sample multiple peaks from first dimensional analysis without risking temporary overlap of second dimensional analysis. Multiple heart-cutting (mLC-LC) utilizes a setup of multiple sampling loops. For 2D-LC, peak capacity is a very important issue. This can be generated using gradient elution separation with much greater efficiency than an isocratic separation given a reasonable amount of time. While isocratic elution is much easier on a fast time scale, it is preferable to perform a gradient elution separation in the second dimension. The mobile phase strength is varied from a weak eluent composition to a stronger one.
== Structure == Lysine carboxypeptidase has a molecular weight of between 270 and 330 kDa (kilodaltons). It is a tetrameric glycoprotein. It is composed of two 83 kDa subunits and two active subunits between 55 kDa and 48 kDa and these are held together by non-covalent interactions. The 83 kDa subunits are regulatory and do not directly contribute to catalytic activity; they are also heavily glycosylated. These function to stabilize the active subunits and keep them in circulation. Catalytic functioning is retained when the 83 kDa subunits are eliminated from the active subunits, but they are still necessary for their support roles. The active subunits are small and relatively unstable at body temperature and blood pH, so they would not last long in the plasma without the regulatory subunits attached. The 55 kDa-48 kDa portions are both catalytically active. The primary structure of the 83 kDa subunit can be split into three main domains. The first domain is located at the N-terminus and consists of 52 amino acids with the first 27 being cysteine-rich. The second domain refers to the next 312 amino acids and it consists of 13 leucine-rich repeat (LRR) sections, each made up of 24 residues. The final C-terminal domain refers to the last 145 residues where amino acids 400-425 hold a cysteine-rich section. The secondary/tertiary structure of the subunit has not yet been experimentally determined, but it has been hypothesized based upon how other LRR proteins fold.
These two components, used together, allow a much finer degree of substance identification than either unit used separately. It is not possible to make an accurate identification of a particular molecule by gas chromatography or mass spectrometry alone. The mass spectrometry process normally requires a very pure sample while gas chromatography using a traditional detector (e.g. Flame ionization detector) cannot differentiate between multiple molecules that happen to take the same amount of time to travel through the column (i.e. have the same retention time), which results in two or more molecules that co-elute. Sometimes two different molecules can also have a similar pattern of ionized fragments in a mass spectrometer (mass spectrum). Combining the two processes reduces the possibility of error, as it is extremely unlikely that two different molecules will behave in the same way in both a gas chromatograph and a mass spectrometer. Therefore, when an identifying mass spectrum appears at a characteristic retention time in a GC–MS analysis, it typically increases certainty that the analyte of interest is in the sample.
While working at St Mary's Hospital, London, in 1928, a Scottish physician, Alexander Fleming, was investigating the pattern of variation in S. aureus. He was inspired by the discovery of an Irish physician, Joseph Warwick Bigger, and his two students, C.R. Boland and R.A.Q. O’Meara, at Trinity College, Dublin, in 1927. Bigger and his students found that when they cultured a particular strain of S. aureus, which they had designated "Y" and isolated a year earlier from the pus of a patient's axillary abscess, the bacterium grew into a variety of strains. They published their discovery as "Variant colonies of Staphylococcus aureus" in The Journal of Pathology and Bacteriology, concluding:
Sources: en.wikipedia.org
SR9009 is a synthetic REV-ERB agonist used in laboratory research. It is not an approved drug, and its effects in humans are not well characterized. It is often sold as a research chemical under the name Stenabolic.
No. SR9009 targets the nuclear receptors REV-ERBα and REV-ERBβ, not the androgen receptor. This mechanism differs from selective androgen receptor modulators and from exercise mimetics that act on PPARδ.
Published evidence is mainly preclinical, using cell cultures and animal models. Controlled human trials are not well documented in the public literature. Claims about human performance or health effects therefore remain unsupported by robust clinical data.
The most common approach is liquid chromatography-tandem mass spectrometry, often after extraction from blood, urine, or tissue. Ultraviolet detection and nuclear magnetic resonance spectroscopy are used mainly for reference material characterization. Isotope-labeled internal standards improve accuracy.