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.
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.
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.
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.
Quality control for research materials includes identity confirmation by nuclear magnetic resonance and purity assessment by high-performance liquid chromatography. Mass spectrometry provides molecular weight confirmation and can detect related impurities. Purchasers should request a certificate of analysis that lists lot-specific data. Online products advertised for human use often lack such documentation. Distinguishing legitimate research material from mislabeled or contaminated samples is a recurring challenge in independent testing, and independent laboratories may use orthogonal methods to verify identity.
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.
Laboratory studies often administer SR9009 by injection because oral absorption appears poor in rodents. Reported pharmacokinetic properties include rapid metabolism and low systemic exposure after oral dosing. Human pharmacokinetic data are sparse, so absorption, distribution, metabolism, and excretion in people are not well defined. Some research explores related REV-ERB compounds with improved drug-like properties. Regulatory approval for any REV-ERB agonist as a human medicine has not been granted to date.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ, also called NR1D1 and NR1D2. These receptors help regulate circadian rhythms and metabolic gene programs. The compound was developed for laboratory research, not as an approved therapeutic. Its identity is distinct from steroid hormones and selective androgen receptor modulators. Scientific interest centers on how REV-ERB activation changes gene expression in cells and animal models.
== Reactivity == Active esters are mainly used as acylating agents. They undergo the same reactions as their unactivated analogues but do so more rapidly. They are prone to hydrolysis, for example. Of great interest is the enhanced reactivity of active esters toward amines to give amides.
== Epidemiology == An estimated 20 per million live births are diagnosed with EB, and 9 per million people in the general population have the condition. Of these cases, approximately 92% are EBS, 5% are DEB, 1% are JEB, and 2% are unclassified. Carrier frequency ranges from 1 in 333 for JEB, to 1 in 450 for DEB; the carrier frequency for EBS is presumed to be much higher than JEB or DEB. The disorder occurs in every racial and ethnic group and affects both sexes.
A long amino-terminal non-collagenous domain (NC-1) of 120 amino acids which can be divided in three parts: a short cytoplasmic region, a transmembrane region and a short extracellular region. A 420-amino-acid-long extracellular region organized in three collagenous (COL1, COL2 and COL3) domains which are interrupted by short non-collagenous domains (NC2, NC3 and NC4), as shown in the schematic.
To better understand the challenges for building full-thickness engineered oral mucosa it is important to first understand the structure of normal oral mucosa. Normal oral mucosa consists of two layers, the top stratified squamous epithelial layer and the bottom lamina propria. The epithelial layer consists of four layers:
=== Scarless wound healing === Scarless wound healing is a concept based on the healing or repair of the skin (or other tissue/organs) after injury with the aim of healing with subjectively and relatively less scar tissue than normally expected. Scarless healing is sometimes mixed up with the concept of scar free healing, which is wound healing that results in absolutely no scar (free of scarring) may occur naturally at some locations of the human body and research in 2025 has decoded molecular players that drive that scarless healing. However, they are different concepts. The opposite of scarless wound healing is scarification (wound healing to scar more). Historically, certain cultures consider scarification attractive; however, this is generally not the case in the modern western society, in which many patients are turning to plastic surgery clinics with unrealistic expectations. Depending on scar type, treatment may be invasive (intralesional steroid injections, surgery) and/or conservative (compression therapy, topical silicone gel, brachytherapy, photodynamic therapy). Clinical judgment is necessary to successfully balance the potential benefits of the various treatments available against the likelihood of a poor response and possible complications resulting from these treatments. Many of these treatments may only have a placebo effect, and the evidence base for the use of many current treatments is poor.
Sources: en.wikipedia.org
=== Radiotherapy === Low-dose, superficial radiotherapy is sometimes used to prevent recurrence of severe keloid and hypertrophic scarring. It is thought to be effective despite a lack of clinical trials, but only used in extreme cases due to the perceived risk of long-term side effects.
== Treatment for collagen loss == Some of the causatives that break down collagen include spending too much time in the sun, smoking, dehydration, and stress. Thus, loss of collagen can be prevented via dietary changes, which may increase the turnover of cells and increase the creation of collagen, as well as lifestyle changes, including applying an adequate amount of sunscreen to prevent UV rays from the sun from damaging the skin and partaking in stress-relieving activities. Other interventions, such as taking vitamins C and A, can provide a boost to collagen production in the body. Consuming nutritious foods rich in the necessary vitamins, minerals, and amino acids promotes collagen production and reduces cellular damage within the body.
Osteogenesis imperfecta, type I: Osteogenesis imperfecta is the most common disorder caused by mutations in this gene. Mutations that inactivate one of the two copies of the COL1A1 gene cause osteogenesis imperfecta type I. The mutated copy of the gene does not produce any pro-alpha1(I) collagen chains. Because only one copy of the gene is directing the cell to make pro-alpha1(I) chains, cells from people with this disorder make only half of the normal amount of type I collagen, which results in bone fragility and other symptoms. Osteogenesis imperfecta, type II: Many different types of mutations in the COL1A1 gene can cause osteogenesis imperfecta type II. These mutations range from missing pieces of the COL1A1 gene to amino acid substitutions, in which the amino acid glycine is replaced by another amino acid in the protein strand. Sometimes one end of the gene (called the C-terminus) is altered, which interferes with the association of the protein strands. All of these changes prevent the normal production of mature type I collagen, which results in this severe condition, type II osteogenesis imperfecta. Osteogenesis imperfecta, type III: Mutations in the COL1A1 gene may result in the production of a protein that is missing segments, making it unusable for collagen production. Other mutations cause the amino acid glycine to be replaced by a different amino acid in the pro-alpha1(I) chain, which inhibits the essential interaction between protein chains.
=== Osteogenesis imperfecta (types 1–4) === Mutations in COL1alpha 1 and/or COL1alpha2 are known to cause several different types of osteogenesis imperfecta with the severity of said diseases being related to the type and frequency of the mutations occurring. For further information on COL1's effect in this disease, see Collagen, type 1, alpha 1.
Sources: en.wikipedia.org
Tendinosis: non-inflammatory injury to the tendon at the cellular level. The degradation is caused by damage to collagen, cells, and the vascular components of the tendon, and is known to lead to rupture. Observations of tendons that have undergone spontaneous rupture have shown the presence of collagen fibrils that are not in the correct parallel orientation or are not uniform in length or diameter, along with rounded tenocytes, other cell abnormalities, and the ingrowth of blood vessels. Other forms of tendinosis that have not led to rupture have also shown the degeneration, disorientation, and thinning of the collagen fibrils, along with an increase in the amount of glycosaminoglycans between the fibrils. Tendinitis: degeneration with inflammation of the tendon as well as vascular disruption. Paratenonitis: inflammation of the paratenon, or paratendinous sheet located between the tendon and its sheath. Tendinopathies may be caused by several intrinsic factors including age, body weight, and nutrition. The extrinsic factors are often related to sports and include excessive forces or loading, poor training techniques, and environmental conditions.
Although americium was likely produced in previous nuclear experiments, it was first intentionally synthesized, isolated and identified in late autumn 1944, at the University of California, Berkeley, by Glenn T. Seaborg, Leon O. Morgan, Ralph A. James, and Albert Ghiorso. They used a 60-inch cyclotron at the University of California, Berkeley. The element was chemically identified at the Metallurgical Laboratory (now Argonne National Laboratory) of the University of Chicago. Following the lighter neptunium, plutonium, and heavier curium, americium was the fourth transuranium element to be discovered. At the time, the periodic table had been restructured by Seaborg to its present layout, containing the actinide row below the lanthanide one. This led to americium being located right below its twin lanthanide element europium; it was thus by analogy named after the Americas: "The name americium (after the Americas) and the symbol Am are suggested for the element on the basis of its position as the sixth member of the actinide rare-earth series, analogous to europium, Eu, of the lanthanide series." The new element was isolated from its oxides in a complex, multi-step process. First plutonium-239 nitrate solution was coated on a platinum foil of about 0.5 cm2 area, the solution was evaporated and the residue was converted into plutonium dioxide (PuO2) by calcining. After cyclotron irradiation, the coating was dissolved with nitric acid, and then precipitated as the hydroxide using concentrated aqueous ammonia solution. The residue was dissolved in perchloric acid.
Psychiatry refers to a field of medicine focused specifically on the mind, aiming to study, prevent, and treat mental disorders in humans. It has been described as an intermediary between the world from a social context and the world from the perspective of those who are mentally ill. People who specialize in psychiatry often differ from most other mental health professionals and physicians in that they must be familiar with both the social and biological sciences. The discipline studies the operations of different organs and body systems as classified by the patient's subjective experiences and the objective physiology of the patient. Psychiatry treats mental disorders, which are conventionally divided into three general categories: mental illnesses, severe learning disabilities, and personality disorders. Although the focus of psychiatry has changed little over time, the diagnostic and treatment processes have evolved dramatically and continue to do so. Since the late 20th century, the field of psychiatry has continued to become more biological and less conceptually isolated from other medical fields.
1 On 1 August 1999, David Hamill was required to stand aside as Treasurer while investigations by the Auditor-General and the Criminal Justice Commission into the awarding of an Internet gaming licence was in process. Premier Peter Beattie served as Acting Treasurer and brought down a budget on 14 September. On 30 September, both inquiries cleared Hamill of any wrongdoing and he was reinstated. 2 On 14 December 1999, Bob Gibbs resigned from Parliament to accept a role as trade commissioner to Los Angeles. Terry Mackenroth assumed his Sport portfolio (losing Rural Communities to Henry Palaszczuk), with Tourism and Racing going to junior minister Merri Rose. Parliamentary secretary to the Deputy Premier, Stephen Robertson, was appointed as a minister and took on Rose's former role of Emergency Services. 3 On 22 November 1999, Deputy Premier Jim Elder, who was Acting Premier at the time due to the Premier being overseas, resigned following allegations that he was under suspicion for having illegally signed electoral forms for family members in his own seat. His portfolios were assumed for four days by Paul Braddy, then for another four by Premier Peter Beattie, before a minor reshuffle on 30 November 2000 which saw, among other things, Terry Mackenroth's promotion to Deputy Premier and Nita Cunningham's appointment to the Ministry.
=== Food industry === The calcium sulfate hydrates are used as a coagulant in products such as tofu. For the FDA, it is permitted in cheese and related cheese products; cereal flours, bakery products, frozen desserts, artificial sweeteners for jelly & preserves, condiment vegetables, and condiment tomatoes, and some candies. It is known in the E number series as E516, and the UN's FAO knows it as a firming agent, a flour treatment agent, a sequestrant, and a leavening agent.
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.