NR1D1 raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-05-19. Anything still debated is marked as such rather than presented as settled.
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.
Handling recommendations for SR9009 in a laboratory setting include storing the solid at low temperature, protected from light and moisture. The compound is often dissolved in dimethyl sulfoxide or ethanol for experiments. Solutions should be prepared with appropriate personal protective equipment and disposed of according to local rules. Stability data for long-term storage are limited, so stock solutions are typically kept cold and used within defined periods. Records of preparation date and concentration support reproducibility.
SR9009 is not approved as a medicine by major regulatory agencies. It is commonly sold as a research chemical, a category that may fall outside customary drug approval and quality rules. In sports, the World Anti-Doping Agency lists SR9009 as a prohibited substance. Athletes who use it can face sanctions if it is detected in a sample. Legal status varies by country, and importation may be restricted. Enforcement practices differ across borders.
Detection of SR9009 in biological samples usually employs liquid chromatography coupled with tandem mass spectrometry. This method can identify the parent compound and sometimes metabolites in urine or blood. Because exposure can be low and clearance may be rapid, sample timing and limits of detection matter. Laboratories validate assays for sensitivity and specificity. Results are interpreted alongside chain-of-custody and quality-control records. Urine is the common matrix for anti-doping analysis, while blood may be used in research settings.
| 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 |
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.
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.
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.
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.
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.
== History == Approval by the US Food and Drug Administration (FDA) was based on TRIDENT-1, a global, multicenter, single-arm, open-label, multi-cohort clinical trial (NCT03093116) which included participants with ROS1-positive locally advanced or metastatic non-small cell lung cancer. Efficacy was evaluated in 71 ROS1 tyrosine kinase inhibitor-naïve participants who received up to one prior line of platinum-based chemotherapy and/or immunotherapy and 56 participants who received one prior ROS1 tyrosine kinase inhibitor with no prior platinum-based chemotherapy or immunotherapy. The FDA granted the application for repotrectinib priority review, breakthrough therapy, and fast track designations.
Protein C is a major component in anticoagulation in the human body. It acts as a serine protease zymogen: APC proteolyses peptide bonds in activated Factor V and Factor VIII (Factor Va and Factor VIIIa), and one of the amino acids in the bond is serine. These proteins that APC inactivates, Factor Va and Factor VIIIa, are highly procoagulant cofactors in the generation of thrombin, which is a crucial element in blood clotting; together they are part of the prothrombinase complex. Cofactors in the inactivation of Factor Va and Factor VIIIa include protein S, Factor V, high-density lipoprotein, anionic phospholipids and glycosphingolipids. Factor Va binds to prothrombin and Factor Xa, increasing the rate at which thrombin is produced by four orders of magnitude (10,000x). Inactivation of Factor Va thus practically halts the production of thrombin. Factor VIII, on the other hand, is a cofactor in production of activated Factor X, which in turn converts prothrombin into thrombin. Factor VIIIa augments Factor X activation by a factor of around 200,000. Because of its importance in clotting, Factor VIII is also known as anti-haemophilic factor, and deficiencies of Factor VIII cause haemophilia A. APC inactivates Factor Va by making three cleavages (Arg306, Arg506, Arg679). The cleavages at both Arg306 and Arg506 diminish the molecule's attraction to Factor Xa, and though the first of these sites is slow to be cleaved, it is entirely necessary to the functioning of Factor V.
=== The Hagedorn Prize === The Hagedorn Prize, named after Hans Christian Hagedorn, celebrates achievements in the understanding and treatment of diabetes. Hagedorn's work significantly advanced the quality of insulin production and diabetes care, making this award a tribute to his legacy in the field. The Hagedorn Prize is recognised as the most prestigious award in Internal Medicine in Denmark.. Hagedorn died in 1971 at age 83.
Article LV of Title III of the Concordat specified that "the registers kept by religious ministers, being and only concerning the administration of sacraments, cannot under any circumstances replace the registers required by law to document the civil status of French citizens." Nevertheless, these religious registers were largely used to reconstruct Paris's civil records after the 1871 disaster.
Structural and computational studies have revealed that the metal binds the two carbonyl oxygens of the methylglyoxal moiety at two of its coordination sites, stabilizing the enediolate anion intermediate. Another unusual property of glyoxalase I is its inconsistent stereospecificity. The first step of its reaction mechanism (the abstraction of the proton from C1 and subsequent protonation of O2) is not stereospecific and works equally well regardless of the initial chirality at C1 in the hemithioacetal substrate. The resulting enediolate intermediate is achiral, but the second step of the reaction mechanism (the abstraction of a proton from O1 and subsequent protonation of C2) is definitely stereospecific, producing only the (S) form of D-lactoylglutathione. This is believed to result from the two glutamates bound oppositely on the metal ion; either one is able to carry out the first step, but only one is able to carry out the second step. The reason from this asymmetry is not yet fully determined.
Sources: en.wikipedia.org
== Risks == The use of sedative medications in older people generally should be avoided. These medications are associated with poorer health outcomes, including cognitive decline, fall, and bone fractures. Sedatives and hypnotics should also be avoided in people with dementia, according to the clinical guidelines known as the Medication Appropriateness Tool for Comorbid Health Conditions in Dementia (MATCH-D). The use of these medications can further impede cognitive function for people with dementia, who are also more sensitive to side effects of medications. Some hypnotics, such as low-dose doxepin, melatonin receptor agonists, and orexin receptor antagonists, may be safer and more appropriate in older adults however.
== Gene == The gene encoding this enzyme has been identified by Jakub Drozak and coworkers in 2010. The gene encoding the Carnosine synthase is ATPGD1, a member of the “ATP-grasp family” of ligases. Because of its involvement in the formation of carnosine, this gene is now also named 'CARNS1'.
Oxycodone/aspirin (trade name Percodan) is a combination drug marketed by Endo Pharmaceuticals. It is a tablet containing a mixture of 325 mg (5 grains) of aspirin and 4.8355 mg of oxycodone HCl (equivalent to 4.3346 mg of oxycodone as the free base); it is an opioid/non-opioid combination used to treat moderate to moderately severe pain. The safety of the combination during pregnancy has not been established, although aspirin is generally contraindicated during pregnancy, and the drug has been placed in pregnancy category D. Inactive ingredients include D&C Yellow 10, FD&C Yellow 6, microcrystalline cellulose, and corn starch. Percodan was first marketed by DuPont Pharmaceuticals and prescribed in the United States in 1950. Once a widely prescribed painkiller, it has largely been replaced by alternative oxycodone compounds containing paracetamol (acetaminophen) instead of aspirin, such as Percocet.
== Pharmacokinetics == The molecular weight, bioavailability, protein binding, elimination half-life, the time to achieve maximum plasma concentration and binding affinity are present in the table below.
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.
Its legal status depends on the country and intended use. It is not an approved medicine in major jurisdictions. In sport, it is prohibited by anti-doping rules.