A practical reference on HPLC-UV: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-12-27 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small-molecule nuclear receptor ligand |
| Appearance | Off-white to pale yellow solid | Typical for research-grade powder |
| Solubility class | Soluble in DMSO; low water solubility | Common stock solutions use organic solvent |
| Typical stock solvent | Dimethyl sulfoxide | Used for laboratory assays |
| Common analytical method | HPLC with UV or mass detection | Used for identity and purity checks |
Laboratory identification of SR9009 typically relies on chromatographic separation coupled to mass spectrometry, often with ultraviolet detection as a secondary check. Nuclear magnetic resonance spectroscopy can confirm molecular structure when a reference standard is available. Because many suppliers sell the compound as a research chemical, independent identity testing is important for experimental reproducibility. A single retention time is not sufficient proof of identity, especially when related compounds may be present. Purity assessments usually report a percentage based on area normalization.
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.
SR9009 is a synthetic small molecule studied as a REV-ERB agonist. REV-ERBα and REV-ERBβ are nuclear receptors that help regulate circadian rhythms and metabolic gene expression. The compound was identified in academic screening efforts to find synthetic ligands for these receptors. In cell and animal studies, SR9009 alters transcription of genes involved in lipid and glucose metabolism, and it can shift circadian behavior. It is not an approved therapeutic agent.
Mechanistically, SR9009 binds the ligand-binding domain of REV-ERBα/β and enhances recruitment of corepressor complexes. This represses target genes rather than activating them. Because REV-ERB proteins normally compete with ROR proteins at shared response elements, the net effect depends on tissue and timing. Researchers use SR9009 to probe how nuclear receptor signaling links the clock to metabolism, inflammation, and muscle biology. Findings are largely preclinical, and the precise contribution of each receptor subtype remains under study.
SR9009 is frequently discussed in fitness and research-chemical contexts, yet it has no approved medical indication. Regulatory agencies have not authorized it for human use, and it is not a standard prescription drug. Some sports organizations list it as a prohibited substance because of its potential performance-enhancing properties. Published human data are sparse, so claims about its effects in people often rely on animal models or anecdotal reports. Quality and identity of online materials can vary widely.
He explored this topic in his book Panic Nation (2006), which he co-authored with Stanley Feldman. Marks gained prominence in the medico-legal field, providing expert opinions in notable cases. His testimony in Danish-born British socialite Claus von Bülow's 1985 trial challenged accusations of insulin injection and led to an acquittal. The case was made into a book and later into an Oscar winning movie, Reversal of Fortune. In his testimony, Marks said that the insulin-covered needle was most likely planted by someone who did not realize that insulin is cleaned off the needles once it is injected. Marks also testified against Beverley Allitt in 1993, who used insulin to murder four children, and at the trial of Colin Norris in 2008. In 2007, he co-authored Insulin Murders detailing his involvement in high-profile medico-legal cases and reflecting on his career. The book was among the first to talk about insulin as a murder weapon and documented more than 50 years of medical cases in which insulin had been used as a weapon. Marks retired in 1995 but remained active as an emeritus professor, contributing to research, publishing, and medico-legal work. He served as the president at the Association of Clinical Biochemists between 1989 and 1991, and as the vice president at the Royal College of Pathologists. In a career spanning more than 50 years, he authored over 50 papers, contributed to more than 300 research publications, and authored almost 20 textbooks. His last book, The Forensic Aspects of Hypoglycaemia, was published in 2019.
In conjunction with the construction of Einstein's first building, New York City built a 1,349-bed, $37.5 million hospital adjacent to the school, now known as the Jacobi Medical Center. Belkin and New York City Mayor Vincent Impellitteri agreed to permit its use as Einstein's teaching hospital. Jacobi is a member of NYC Health + Hospitals, the largest municipal health system in the United States. It serves as both the regional snakebite center and hyperbaric center for the New York tri-state area.
=== Chemical properties === Perfluoroalkanes are very stable because of the strength of the carbon–fluorine bond, one of the strongest in organic chemistry. Its strength is a result of the electronegativity of fluorine imparting partial ionic character through partial charges on the carbon and fluorine atoms, which shorten and strengthen the bond (compared to carbon-hydrogen bonds) through favorable covalent interactions. Additionally, multiple carbon–fluorine bonds increase the strength and stability of other nearby carbon–fluorine bonds on the same geminal carbon, as the carbon has a higher positive partial charge. Furthermore, multiple carbon–fluorine bonds also strengthen the "skeletal" carbon–carbon bonds from the inductive effect. Therefore, saturated fluorocarbons are more chemically and thermally stable than their corresponding hydrocarbon counterparts, and indeed any other organic compound. They are susceptible to attack by very strong reductants, e.g. Birch reduction and very specialized organometallic complexes. Fluorocarbons are colorless and have high density, up to over twice that of water. They are not miscible with most organic solvents (e.g., ethanol, acetone, ethyl acetate, and chloroform), but are miscible with some hydrocarbons (e.g., hexane in some cases). They have very low solubility in water, and water has a very low solubility in them (on the order of 10 ppm). They have low refractive indices.
All mRNA templates used for mRNA display technology have puromycin at their 3' end. As translation proceeds, the ribosome moves along the mRNA template, and once it reaches the 3' end of the template, the fused puromycin will enter ribosome's A site and be incorporated into the nascent peptide. The mRNA-peptide fusion is then released from the ribosome (Figure 1). To synthesize an mRNA-peptide fusion, the fused puromycin is not the only modification to the mRNA template. Oligonucleotides and other spacers need to be incorporated along with the puromycin to provide flexibility and proper length for the puromycin to enter the A site. Ideally, the linker between the 3' end of an mRNA and the puromycin has to be flexible and long enough to allow the puromycin to enter the A site upon translation of the last codon. This enables the efficient production of high-quality, full-length mRNA-peptide fusions. Rihe Liu et al. optimized the 3'-puromycin oligonucleotide spacer. They reported that dA25 (a nucleotide sequence of 25 deoxyadenosine residues) in combination with a Spacer 9 (Glen Research), and dAdCdCP at the 5' terminus worked the best for the fusion reaction. They found that linkers longer than 40 nucleotides and shorter than 16 nucleotides showed greatly reduced efficiency of fusion formation. Also, when the sequence rUrUP was present adjacent to the puromycin, fusion did not form efficiently.
Sources: en.wikipedia.org
== Mechanism of action == The mechanism of action of omadacycline is similar to that of other tetracyclines – inhibition of bacterial protein synthesis. Omadacycline has activity against bacterial strains expressing the two main forms of tetracycline resistance (efflux and ribosomal protection).
=== Conversion of carbohydrates into fatty acids and cholesterol === The pyruvate produced by glycolysis is an important intermediary in the conversion of carbohydrates into fatty acids and cholesterol. This occurs via the conversion of pyruvate into acetyl-CoA in the mitochondrion. However, this acetyl CoA needs to be transported into cytosol where the synthesis of fatty acids and cholesterol occurs. This cannot occur directly. To obtain cytosolic acetyl-CoA, citrate (produced by the condensation of acetyl CoA with oxaloacetate) is removed from the citric acid cycle and carried across the inner mitochondrial membrane into the cytosol. There it is cleaved by ATP citrate lyase into acetyl-CoA and oxaloacetate. The oxaloacetate is returned to mitochondrion as malate (and then back into oxaloacetate to transfer more acetyl-CoA out of the mitochondrion). The cytosolic acetyl-CoA can be carboxylated by acetyl-CoA carboxylase into malonyl CoA, the first committed step in the synthesis of fatty acids, or it can be combined with acetoacetyl-CoA to form 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) which is the rate limiting step controlling the synthesis of cholesterol. Cholesterol can be used as is, as a structural component of cellular membranes, or it can be used to synthesize the steroid hormones, bile salts, and vitamin D.
=== Reproduction studies === Patulin decreased sperm count and altered sperm morphology in the rat. Also, it resulted in abortion of F1 litters in rats and mice after i.p. injection. Embryotoxicity and teratogenicity were also reported in chick eggs.
Sources: en.wikipedia.org
Competition between RNA may have favored the emergence of cooperation between different RNA chains, opening the way for the formation of the first protocell. Eventually, RNA chains developed with catalytic properties that help amino acids bind together (a process called peptide-bonding). These amino acids could then assist with RNA synthesis, giving those RNA chains that could serve as ribozymes the selective advantage. The ability to catalyze one step in protein synthesis, aminoacylation of RNA, has been demonstrated in a short (five-nucleotide) segment of RNA. In 2014, a group of researchers managed to produce all four components of RNA by simulating an asteroid impact in primordial conditions. In March 2015, NASA scientists reported that, for the first time, complex DNA and RNA organic compounds of life, including uracil, cytosine, and thymine, have been formed in the laboratory under conditions found only in outer space, using starting chemicals, like pyrimidine, found in meteorites. Pyrimidine, like polycyclic aromatic hydrocarbons (PAHs), may have been formed in red giant stars or in interstellar dust and gas clouds, according to the scientists. That same month, researchers were able to produce over 50 aminoacids in a laboratory setting by using only hydrogen sulfide, hydrogen cyanide (presumably produced after outer space meteorites reacted with atmospheric nitrogen) and ultraviolet light.
== Biosynthesis == The biosynthesis of menthol has been investigated in Mentha × piperita and the enzymes involved in have been identified and characterized. It begins with the synthesis of the terpene limonene, followed by hydroxylation, and then several reduction and isomerization steps. More specifically, the biosynthesis of (−)-menthol takes place in the secretory gland cells of the peppermint plant. The steps of the biosynthetic pathway are as follows:
Lisdexamphetamine (also known as Lisdexamfetamine Dimesylate), and sold under the brand names Vyvanse ( , VY-vans) and Elvanse among others, is a stimulant medication that is used as a treatment for attention deficit hyperactivity disorder (ADHD) in both children and adults, and for moderate-to-severe binge eating disorder in adults. A prodrug of dextroamphetamine, lisdexamphetamine is taken by mouth. Its effects generally begin within 90 minutes and last for up to 14 hours. Common side effects of lisdexamphetamine include hypertension, loss of appetite, anxiety, diarrhea, trouble sleeping, irritability, and nausea. Rare but serious side effects include mania, sudden cardiac death in those with underlying heart problems, and psychosis. It has a high potential for substance abuse. Serotonin syndrome may occur if used with certain other medications. Its use during pregnancy may result in harm to the fetus, and use during breastfeeding is not recommended by the manufacturer as dextroamphetamine (its metabolite) can pass through the breastmilk. Lisdexamphetamine is an inactive prodrug that is formed by the condensation of L-lysine, a naturally occurring amino acid, and dextroamphetamine. In the blood, peptidase enzymes reverse this process to release the active agent, the central nervous system (CNS) stimulant dextroamphetamine. Lisdexamphetamine was approved for medical use in the United States in 2007 and in the European Union in 2012. In 2023, it was the 76th most commonly prescribed medication in the United States, with more than 9 million prescriptions.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that acts on REV-ERB nuclear receptors. It is not approved for human use and is sold only as a research chemical. Its effects have been studied mainly in cells and rodents.
It binds REV-ERB alpha and REV-ERB beta and changes the expression of genes tied to metabolism and circadian rhythm. These changes can affect mitochondria and energy use in animal models. The exact chain from receptor binding to physiological outcome is still being mapped.
No reliable human trials show that SR9009 improves athletic performance. Some rodent studies report endurance changes, but these results are not proof of human benefit. Its use in sport is prohibited, and quality and safety data are lacking.
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.