A practical reference on LC-MS: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-10 and is reviewed periodically as new material appears.
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.
The mechanism of action involves binding to REV-ERB receptors and recruiting corepressor complexes, which represses target gene transcription. This contrasts with many nuclear receptor agonists that activate transcription. Downstream effects may include changes in autophagy, mitochondrial biogenesis, and lipid handling, but the precise pathways remain an active area of study. Whether these molecular events translate into meaningful physiological effects in humans is unresolved. Most evidence comes from cultured cells and rodent models rather than human participants.
SR9009 is a synthetic small molecule developed as an agonist of the nuclear receptors REV-ERBα (NR1D1) and REV-ERBβ (NR1D2). These receptors help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, SR9009 alters transcription of genes involved in lipid metabolism, inflammation, and mitochondrial function. It is not an approved medicine, and its pharmacological profile in humans remains largely uncharacterized. The compound is frequently discussed in the context of circadian biology and metabolic research rather than clinical use.
Preclinical reports have linked SR9009 to improved endurance and altered energy expenditure in rodents. Such findings have prompted interest in whether REV-ERB activation can influence skeletal muscle metabolism. However, the reported effects depend on dose, route, and experimental model, and replication across laboratories is limited. Human trials have not established comparable outcomes, so claims about exercise performance remain speculative. The absence of controlled human data is a central limitation in interpreting these observations.
| Property | Value | Notes |
|---|---|---|
| Appearance | Off-white to pale yellow solid | Visual description varies with purity and source |
| Solubility | Soluble in DMSO and ethanol; poorly soluble in water | Organic stock solutions are common in research |
| Typical storage | -20 °C, desiccated, protected from light | Avoid repeated freeze-thaw cycles |
| Typical analytical method | LC-MS or HPLC-UV | Reference standards are needed for quantification |
| Molar mass | Approximately 437.9 g/mol | Calculated from the reported free-base formula |
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.
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.
Detection of SR9009 in biological samples usually relies on liquid chromatography coupled to tandem mass spectrometry. This approach separates the compound from matrix components and identifies it by mass transitions. Because SR9009 can undergo metabolism, laboratories often look for both parent drug and specific metabolites. Sample preparation may involve protein precipitation or solid-phase extraction. Method validation examines sensitivity, carryover, and interference from related substances, and reference standards are required for accurate calibration.
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.
== Etymology == The word homeostasis ( hoh-mee-oh-STAY-sis) uses combining forms of homeo- and -stasis, Neo-Latin from Greek: ὅμοιος homoios, "similar" and στάσις stasis, "standing still", yielding the idea of "staying the same".
== Treatment and prognosis == Treatment is symptomatic and includes the administration of non-steroidal anti-inflammatory agents or the application of heat to the affected muscles. Intercostal 2% xylocaine injections with normal saline have been used to relieve symptoms in certain cases. Relapses during the weeks following the initial episode are a characteristic feature of this disease. Bornholm disease typically lasts between one day and one week with an average illness duration of four days. In 20% of cases studied, the illness lasted between one and two weeks. The illness in children was found to be shorter than the illness in adults. Patients typically make a complete recovery with supportive care. Although recovering from Bornholm disease is expected, some rare complications include myocarditis, respiratory failure, hepatic necrosis with coagulopathy, and disseminated intravascular coagulopathy (DIC). Aseptic meningitis, pericarditis and pleurisy are also known potential complications of Bornholm disease. Another uncommon complication is orchitis that manifests as unilateral testicular pain and swelling in the days or weeks following the expected symptoms of Bornholm disease.
=== Particular studies === In a Bulgarian study, after five years, 34% had developed into a defined connective tissue disease (with the highest probability of development being within the first two years after onset of symptoms), 54% continued undifferentiated, and 12% were in remission. In a US study, after 10 years, 37% had developed into a defined connective tissue disease, 43% continued undifferentiated, and 20% were in remission. In a Spanish study, after a mean follow-up of 11±3 years, 14% had developed a definite CTD, 62% continued undifferentiated, and 24% were in remission. In an Italian study (in which 58% had ANA abnormalities), after five years, 6% had developed a defined autoimmune disease. The remaining 94% saw clinical and serological features little changed in the period and quite stable. 11% of these were and remained asymptomatic.
==== Modulation of mitochondrial activity ==== Cannabinoids influence mitochondrial processes, including calcium regulation, apoptosis, electron transport chain activity, mitochondrial respiration and ATP production. Mitochondrial dynamics—encompassing the processes of fusion and fission, as well as alterations in morphology and organelle mobility, are also affected by cannabinoid exposure. In addition, cannabinoids have been shown to modulate mitochondrial biogenesis through the dysregulation of PGC-1α levels. These effects are complex, involving direct membrane interactions and receptor-mediated pathways, but a unified hypothesis is lacking due to conflicting data.
The National Foundation on the Arts and the Humanities is an agency of the United States federal government that was established in 1965 with the purpose to "develop and promote a broadly conceived national policy of support for the humanities and the arts in the United States, and for institutions which preserve the cultural heritage of the United States."
Sources: en.wikipedia.org
== Diagnosis == Assessment of diabetic foot ulcer includes identifying risk factors such as diabetic peripheral neuropathy, noting that 50 percent of people are asymptomatic, and ruling out other causes of peripheral neuropathy, such as alcohol use disorder and spinal injury. Diabetic foot ulcers are often misdiagnosed in patients with undiagnosed skin malignancies, especially high-risk in elderly patients. The location of the ulcer, its size, shape, depth, and whether the tissue is granulating or not need to be considered. Further considerations include whether there is malodour, condition of the border of the wound, and palpable bone and sinus formation should be investigated. Signs of infection require to be considered, such as the development of grey or yellow tissue, purulent discharge, unpleasant smell, sinus, undermined edges, and exposure of bone or tendon.
Mechanical or elastic gauges depend on a Bourdon tube, diaphragm, or capsule, usually made of metal, which will change shape in response to the pressure of the region in question. A variation on this idea is the capacitance manometer, in which the diaphragm makes up a part of a capacitor. A change in pressure leads to the flexure of the diaphragm, which results in a change in capacitance. These gauges are effective from 103 torr to 10−4 torr, and beyond. Thermal conductivity gauges rely on the fact that the ability of a gas to conduct heat decreases with pressure. In this type of gauge, a wire filament is heated by running current through it. A thermocouple or Resistance Temperature Detector (RTD) can then be used to measure the temperature of the filament. This temperature is dependent on the rate at which the filament loses heat to the surrounding gas, and therefore on the thermal conductivity. A common variant is the Pirani gauge which uses a single platinum filament as both the heated element and RTD. These gauges are accurate from 10 torr to 10−3 torr, but they are sensitive to the chemical composition of the gases being measured. Ionization gauges are used in ultrahigh vacuum. They come in two types: hot cathode and cold cathode. In the hot cathode version an electrically heated filament produces an electron beam. The electrons travel through the gauge and ionize gas molecules around them. The resulting ions are collected at a negative electrode. The current depends on the number of ions, which depends on the pressure in the gauge.
The prevalent in political circles nationalism was fueled by the large size of Poland's minority populations and their separate agendas. According to the language criterion of the Polish census of 1931, the Poles constituted 69% of the population, Ukrainians 15%, Jews (defined as speakers of the Yiddish language) 8.5%, Belarusians 4.7%, Germans 2.2%, Lithuanians 0.25%, Russians 0.25% and Czechs 0.09%, with some geographical areas dominated by a particular minority. In time, the ethnic conflicts intensified, and the Polish state grew less tolerant of the interests of its national minorities. In interwar Poland, compulsory free general education substantially reduced illiteracy rates, but discrimination was practiced in a way that resulted in a dramatic decrease in the number of Ukrainian language schools and official restrictions on Jewish attendance at selected schools in the late 1930s. The population grew steadily, reaching 35 million in 1939. However, the overall economic situation in the interwar period was one of stagnation. There was little money for investment inside Poland, and few foreigners were interested in investing there. Total industrial production barely increased between 1913 and 1939 (within the area delimited by the 1939 borders), but because of population growth (from 26.3 million in 1919 to 34.8 million in 1939), the per capita output actually decreased by 18%.
== Treatment == Treatment is predominantly preventive. Avoidance of topical phenols and diets low in tyrosine may help. Replacement and repair of damaged tissue is also possible. Hydroquinone-induced exogenous ochronosis is an avoidable dermatosis that is exceedingly difficult to treat. However, some studies show that treatment may be possible with a Q-switched alexandrite (755 nm) laser. Individuals with this disorder are recommended to stop using hydroquinone-containing compounds. Awareness of this is important, as dermatologists may think the symptoms a patient is exhibiting are a melasma, and prescribe a hydroquinone-containing cream.
Sources: en.wikipedia.org
It is usually detected by LC-MS or HPLC-UV against a reference standard. In biological matrices, metabolite targeting can improve detection. No universal immunoassay is widely available.
The compound is generally handled as light-sensitive and stored cold and dry. Stability in solution depends on solvent, concentration, and storage time. Specific degradation rates are not fully standardized.
Limited water solubility affects formulation for cell and animal studies. Organic co-solvents are often used to dissolve it. Precipitation can confound assay results if not controlled.
It is a synthetic compound that acts as an agonist at REV-ERBα and REV-ERBβ. It is used mainly as a research chemical to study circadian and metabolic pathways. It is not approved for human therapeutic use.