This is a working overview of LC-MS/MS, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 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.
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.
SR9009 is often grouped with compounds studied for circadian and metabolic regulation rather than with classical anabolic steroids. Its interactions with nuclear receptors differ from those of androgen receptor ligands, and its proposed mechanisms involve transcriptional control rather than direct hormone signaling. Some sources classify it as a metabolic modulator because of observed effects on energy utilization. The distinction matters for regulation and for interpreting research results across different compound classes.
SR9009 is a synthetic small molecule developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
Research interest in SR9009 grew from studies showing improved running endurance in mice after short treatment periods. Those experiments linked the compound to increased mitochondrial content and fatty acid oxidation in muscle, but the findings come from animal models and specific dosing schedules. Independent replication has been limited, and the pathways connecting REV-ERB activation to exercise performance are still being mapped. Whether similar responses occur in humans is an open question.
| 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 |
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.
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.
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.
Most published work on SR9009 consists of preclinical studies. It is widely sold as a research chemical, a category that does not imply safety, efficacy, or pharmaceutical-grade quality. Sports anti-doping organizations have listed SR9009 as a prohibited substance, and its presence in an athlete sample can lead to sanctions. Legal status differs by country; in several jurisdictions it is not approved for human consumption and may be treated as an unapproved new drug.
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.
For many mammals, carbohydrates provide a large portion of the daily caloric requirement. To harvest energy from oligosaccharides, they must first be broken down into monosaccharides so they can enter metabolism. Kinases play an important role in almost all metabolic pathways. The figure on the left shows the second phase of glycolysis, which contains two important reactions catalyzed by kinases. The anhydride linkage in 1,3 bisphosphoglycerate is unstable and has a high energy. 1,3-bisphosphogylcerate kinase requires ADP to carry out its reaction yielding 3-phosphoglycerate and ATP. In the final step of glycolysis, pyruvate kinase transfers a phosphoryl group from phosphoenolpyruvate to ADP, generating ATP and pyruvate. Hexokinase is the most common enzyme that makes use of glucose when it first enters the cell. It converts D-glucose to glucose-6-phosphate by transferring the gamma phosphate of an ATP to the C6 position. This is an important step in glycolysis because it traps glucose inside the cell due to the negative charge. In its dephosphorylated form, glucose can move back and forth across the membrane very easily. Mutations in the hexokinase gene can lead to a hexokinase deficiency which can cause nonspherocytic hemolytic anemia. Phosphofructokinase, or PFK, catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate and is an important point in the regulation of glycolysis. High levels of ATP, H+, and citrate inhibit PFK. If citrate levels are high, it means that glycolysis is functioning at an optimal rate. High levels of AMP stimulate PFK.
It is important for MADD patients to maintain strength and fitness without exercising or working to exhaustion. Learning this balance may be more difficult than normally, as muscle pain and fatigue may be perceived differently from normal individuals. Symptomatic relief from the effects of MADD may sometimes be achieved by administering ribose orally at a dose of approximately 10 grams per 100 pounds (0.2 g/kg) of body weight per day, and exercise modulation as appropriate. Taken hourly, ribose provides a direct but limited source of energy for the cells. Patients with myoadenylate deaminase deficiency do not retain ribose during heavy exercise, so supplementation may be required to rebuild levels of ATP. Creatine monohydrate could also be helpful for AMPD patients, as it provides an alternative source of energy for anaerobic muscle tissue and was found to be helpful in the treatment of other, unrelated muscular myopathies. Inborn Errors of Metabolism Metabolic Myopathies Purine Nucleotide Cycle
Aerospace 9100 (AS9100) is an international standard for aerospace management systems that is a widely adopted and standardized quality management system for the aerospace sector. It was developed in March 1999 by Society of Automotive Engineers. The goal of the standard is to provide for continual improvement, emphasizing defect prevention and the reduction of variation and waste in the aerospace industry supply chain and assembly process. The standard was designed to fit into an integrated management system. AS9100 replaces the earlier AS9000 and fully incorporates the entirety of the current version of ISO 9001, while adding requirements relating to quality and safety. Major aerospace manufacturers and suppliers worldwide require compliance with AS9100 as a condition of doing business with them.
The iodine pit, also called the iodine hole or xenon pit, is a temporary disabling of a nuclear reactor due to the buildup of short-lived neutron poisons in the reactor core. The main isotope responsible is 135Xe, mainly produced by beta decay of 135I. 135I is a weak neutron absorber, while 135Xe is the strongest known neutron absorber. When 135Xe builds up in the fuel rods of a reactor, it significantly lowers their reactivity, by absorbing a significant amount of the neutrons that provide the nuclear reaction. The presence of 135I and 135Xe in the reactor is one of the main reasons for its power fluctuations in reaction to change of control rod positions. The buildup of short-lived fission products acting as nuclear poisons is called reactor poisoning, or xenon poisoning. The buildup of stable or long-lived neutron poisons is called reactor slagging.
Liu Wet al found an interesting results when comparing exendin-4 (10 nmol/kg), liraglutide (25 nmol/kg) and lixisenatide (10 nmol/kg), it was found that exendin-4 showed no protective effects at the dose chosen, while both liraglutide and lixisenatide showed effects in preventing the MPTP-induced motor impairment (Rotarod, open-field locomotion, catalepsy test), reduction in tyrosine hydroxylase (TH) levels (dopamine synthesis) in the substantia nigra and basal ganglia, a reduction of the pro-apoptotic signaling molecule BAX and an increase in the anti-apoptotic signaling molecule B-cell lymphoma-2. The previous results demonstrate that both liraglutide and lixisenatide are superior to exendin-4, and both drugs show promise as a novel treatment of Parkinson disease. Another study done by Kerry Hunter et al. profiled the GLP-1 receptor agonists liraglutide and lixisenatide. The kinetics of crossing the blood brain barrier (BBB), activation of the GLP-1R by measuring cAMP levels, and physiological effects in the brain on neuronal stem cell proliferation and neurogenesis were evaluated. Both drugs were able to cross the BBB. Lixisenatide crossed the BBB at all doses tested (2.5, 25, or 250 nmol/kg ip.) when measured 30 min post-injection and at 2.5-25 nmol/kg ip. 3 h post-injection. Lixisenatide also enhanced neurogenesis in the brain. Liraglutide crossed the BBB at 25 and 250 nmol/kg ip. but no increase was detectable at 2.5 nmol/kg ip. 30 min post-injection, and at 250 nmol/kg ip. at 3 h post-injection.
Sources: en.wikipedia.org
===== Ethoxylates ===== Many important surfactants include a polyether chain terminating in a highly polar anionic group. The polyether groups often comprise ethoxylated (polyethylene oxide-like) sequences inserted to increase the hydrophilic character of a surfactant. Polypropylene oxides conversely, may be inserted to increase the lipophilic character of a surfactant, see also poloxamers.
===== North America ===== The U.S. National Academy of Medicine (NAM), on behalf of both the U.S. and Canada, sets Dietary Reference Intakes, including Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs), or Adequate Intakes (AIs) for when there is not sufficient information to set EARs and RDAs. For both males and females under 9 years of age, the AIs for potassium are: 400 mg of potassium for 0 to 6-month-old infants, 860 mg of potassium for 7 to 12-month-old infants, 2,000 mg of potassium for 1 to 3-year-old children, and 2,300 mg of potassium for 4 to 8-year-old children. For males 9 years of age and older, the AIs for potassium are: 2,500 mg of potassium for 9 to 13-year-old males, 3,000 mg of potassium for 14 to 18-year-old males, and 3,400 mg for males that are 19 years of age and older. For females 9 years of age and older, the AIs for potassium are: 2,300 mg of potassium for 9 to 18-year-old females, and 2,600 mg of potassium for females that are 19 years of age and older. For pregnant and lactating females, the AIs for potassium are: 2,600 mg of potassium for 14 to 18-year-old pregnant females, 2,900 mg for pregnant females that are 19 years of age and older; furthermore, 2,500 mg of potassium for 14 to 18-year-old lactating females, and 2,800 mg for lactating females that are 19 years of age and older. As for safety, the NAM also sets tolerable upper intake levels (ULs) for vitamins and minerals, but for potassium the evidence was insufficient, so no UL was established. As of 2004, most Americans adults consume less than 3,000 mg.
Cephalosporins are a broad class of bactericidal antibiotics that include the β-lactam ring and share a structural similarity and mechanism of action with other β-lactam antibiotics (e.g. penicillins, carbapenems and monobactams). The cephalosporins (and other β-lactams) have the ability to kill bacteria by inhibiting essential steps in the bacterial cell wall synthesis which in the end results in osmotic lysis and death of the bacterial cell. Cephalosporins are widely used antibiotics because of their clinical efficiency and desirable safety profile. The cephalosporins are diverse in their antibacterial spectrum, water solubility, acid tolerability, oral bioavailability, biological half-life and other properties. Therefore, the cephalosporins can be further classified into generations depending on antibacterial activity, time of invention and structural basis.
=== Lethality === Calciseptine is toxic in low doses. No specific data are available on the toxicity of calciseptine in humans. However, the LD50 values for mice have been determined and can be found in the table below:
=== Medical research relevance === Enzymatic specificity provides useful insight into enzyme structure, which ultimately determines and plays a role in physiological functions. Specificity studies also may provide information of the catalytic mechanism. Specificity is important for novel drug discovery and the field of clinical research, with new drugs being tested for its specificity to the target molecule in various rounds of clinical trials. Drugs must contain as specific as possible structures in order to minimize the possibility of off-target affects that would produce unfavorable symptoms in the patient. Drugs depend on the specificity of the designed molecules and formulations to inhibit particular molecular targets. Novel drug discovery progresses with experiments involving highly specific compounds. For example, the basis that drugs must successfully be proven to accomplish is both the ability to bind the target receptor in the physiological environment with high specificity and also its ability to transduce a signal to produce a favorable biological effect against the sickness or disease that the drug is intended to negate.
Sources: en.wikipedia.org
The President directed other U.S. government agencies to put their technical assistance in developing countries under FOA's management as well. USDA in particular transferred OFAR's programs to FOA, while reconstituting the Foreign Agricultural Service for the task of building global markets for U.S. farm products. Administrative functions were consolidated as the various agencies came into FOA, and the Mutual Security Act of July 1953 instructed FOA to reduce personnel by at least 10% within 120 days. A large number of TCA's senior professionals were summarily dismissed, and FOA's administrator mounted an effort to compensate for lower U.S. government staffing by drawing on experts from U.S. universities and private voluntary organizations. The ExIm Bank's lending volume in developing countries was also cut dramatically in 1953. While a "trade not aid" strategy required the U.S. to import more goods from its allies, the administration was unable to convince Congress to liberalize import policy. On the contrary, the main foreign commercial measure taken at this time went in the other direction: the U.S. ramped up subsidies for exports of U.S. agricultural products. The 1953 amendment to the Mutual Security Act and the much larger Agricultural Trade Development and Assistance Act of 1954, known as "PL-480", allowed the U.S. government to buy U.S. farm surpluses and sell them in developing countries for inconvertible local currencies. Much of PL-480's foreign-currency revenue was returned to developing countries as a supplement to U.S. development assistance.
==== Use as an inhaled agitation medication ==== Loxapine has a relatively strong safety profile compared to similar antipsychotic drugs, such as quetiapine, olanzapine, and clozapine, with a relatively lower incidence of metabolic side-effects (although higher extrapyramial side-effects). Given its strong safety profile and speed/efficacy when given intramuscularly for acute agitation, an inhaled version of the drug (Adasuve) has been developed to be applied nasally for agitated patients needing to be rapidly de-escalated.
Re-lactation is the process of restarting breastfeeding. In developing countries, mothers may restart breastfeeding after a weaning as part of an oral rehydration treatment for diarrhea. In developed countries, re-lactation is common after early medical problems are resolved, or because a mother changes her mind about breastfeeding. Re-lactation is most easily accomplished with a newborn or with a baby that was previously breastfeeding; if the baby was initially bottle-fed, the baby may refuse to suckle. If the mother has recently stopped breastfeeding, chances are higher that the milk supply will return and be adequate. Although some mothers successfully re-lactate after months-long interruptions, success is higher for shorter interruptions. Techniques to promote lactation include frequent attempts to breastfeed, extensive skin-to-skin contact with the baby, and frequent, long pumping sessions. Suckling may be encouraged with a tube filled with infant formula, so that the baby associates suckling at the breast with food. A dropper or syringe without the needle may be used to place milk onto the breast while the baby suckles. The mother should allow the infant to suckle at least ten times during 24 hours, and more times if the baby is interested. These times can include every two hours, whenever the baby seems interested, longer at each breast, and when the baby is sleepy, when they might suckle more readily. In keeping with increasing contact between mother and child, including increasing skin-to-skin contact, grandmothers should pull back and help in other ways.
A long-chain fatty acid is dehydrogenated to create a trans double bond between C2 and C3. This is catalyzed by acyl CoA dehydrogenase to produce trans-delta 2-enoyl CoA. It uses FAD as an electron acceptor and it is reduced to FADH2. Trans-delta 2-enoyl CoA is hydrated at the double bond to produce L-3-hydroxyacyl CoA by enoyl-CoA hydratase. L-3-hydroxyacyl CoA is dehydrogenated again to create 3-ketoacyl CoA by 3-hydroxyacyl CoA dehydrogenase. This enzyme uses NAD as an electron acceptor. Thiolysis occurs between C2 and C3 (alpha and beta carbons) of 3-ketoacyl CoA. Thiolase enzyme catalyzes the reaction when a new molecule of coenzyme A breaks the bond by nucleophilic attack on C3. This releases the first two carbon units, as acetyl CoA, and a fatty acyl CoA minus two carbons. The process continues until all of the carbons in the fatty acid are turned into acetyl CoA. This acetyl-CoA then enters the mitochondrial tricarboxylic acid cycle (TCA cycle). Both the fatty acid beta-oxidation and the TCA cycle produce NADH and FADH2, which are used by the electron transport chain to generate ATP. Fatty acids are oxidized by most of the tissues in the body. However, some tissues such as the red blood cells of mammals (which do not contain mitochondria) and cells of the central nervous system do not use fatty acids for their energy requirements, but instead use carbohydrates (red blood cells and neurons) or ketone bodies (neurons only).
=== Renewed intensity (24 March – 7 April) === Following the expiration of temporary ceasefire, Pakistani armed forces carried out a drone strike targeting the 209 Al-Fatah Corps in Balkh province during the night of 24 March, according to local Afghan sources. Taliban officials in Balkh confirmed the presence of drones in the province but denied that the base belonging to 209 Al-Fatah Corps had been struck. Taliban claimed that a civilian was killed and three were wounded in Pakistani artillery shelling in Kunar. On 25 March, Faridun Samim, a spokesperson for the Taliban governor in Nuristan said that Pakistani forces were attacking vehicles attempting to enter Kamdesh and Bargi Matal, forcing the closure of roads to both districts while Taliban authorities sought an alternative route. Afghan local sources had earlier reported that daily Pakistani shelling had made access to the areas difficult. According to those sources, around 40 Taliban fighters had been killed in clashes with Pakistani forces, although the figure was not officially confirmed, and Taliban forces had dispatched two battalions to eastern Nuristan to prevent the border districts from being left undefended. Residents said that communication routes in eastern Nuristan, particularly in Kamdesh and Bargi Matal, had been closed for about 20 days due to clashes and Pakistani attacks, causing severe food shortages and seriously affecting daily life.
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 REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.