A practical reference on reference standard: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-05-18. Anything still debated is marked as such rather than presented as settled.
Regulatory status varies by country and intended use. Major drug agencies have not granted marketing authorization for SR9009 as a medicine, and it is not listed as a controlled substance in many jurisdictions. It is often sold as a research chemical, a category that may fall outside pharmaceutical manufacturing rules. Buyers should verify local laws and supplier documentation, including certificates of analysis. The lack of standardized quality controls raises concerns about identity, purity, and actual content in products marketed online.
In laboratory settings, SR9009 is commonly identified by its molecular structure and its interaction with REV-ERB receptors. Vendors may list it under synonyms such as Stenabolic or REV-ERB agonist, but those names do not define purity or identity. Analytical confirmation typically uses high-performance liquid chromatography with ultraviolet detection or liquid chromatography–mass spectrometry. A reference standard is needed to compare retention time and mass spectrum, because the compound can be confused with related research chemicals.
Handling practices for SR9009 focus on minimizing degradation and contamination. The solid is generally stored desiccated at or below -20 °C, protected from light and moisture. Stock solutions are often prepared in dimethyl sulfoxide or ethanol, then aliquoted to avoid repeated freeze–thaw cycles. Aqueous solubility is low, so formulations for animal studies may require cosolvents or suspending agents. Personnel should follow institutional chemical safety procedures, because toxicological data for humans are incomplete.
In rodent studies, SR9009 has been reported to increase mitochondrial content in skeletal muscle and improve exercise endurance under some conditions. These findings led to popular descriptions such as an exercise mimetic, although that term oversimplifies the biology. Effects vary by dose, timing, tissue, and model. The compound's influence on circadian pathways means that time of administration can matter in experiments. Whether similar metabolic changes occur in humans remains largely unexplored in controlled published trials.
Pharmacokinetic data for SR9009 are limited in published literature. Some reports indicate low oral bioavailability and rapid clearance in animals, which complicates interpretation of exposure and effect. Researchers often use injected routes in preclinical work to achieve measurable systemic levels. Analytical studies rely on mass spectrometry to detect the parent compound and its metabolites. Questions about tissue distribution, active metabolites, and long-term consequences remain open. Species differences in metabolism can affect observed half-life and target engagement.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. These receptors help regulate circadian rhythms and metabolic gene expression. In laboratory experiments, SR9009 binds these receptors and alters transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. It is not a naturally occurring compound and has no approved therapeutic use. Research interest stems from its ability to modify energy metabolism in cells and animal models.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white solid | Visual inspection is not sufficient for identity. |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water. |
| Typical storage | -20 °C, desiccated, dark | Protect from repeated temperature changes. |
| Common analytical method | LC-MS or HPLC-UV | Reference standard required for comparison. |
| Common synonyms | SR9009; Stenabolic; REV-ERB agonist | Vendor naming may vary. |
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.
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.
Periodic acid-Schiff is a histology special stain used to mark carbohydrates (glycogen, glycoprotein, proteoglycans). PAS is commonly used on liver tissue where glycogen deposits are made which is done in efforts to distinguish different types of glycogen storage diseases. PAS is important because it can detect glycogen granules found in tumors of the ovaries and pancreas of the endocrine system, as well as in the bladder and kidneys of the renal system. Basement membranes can also show up in a PAS stain and can be important when diagnosing renal disease. Due to the high volume of carbohydrates within the cell wall of hyphae and yeast forms of fungi, the Periodic acid -Schiff stain can help locate these species inside tissue samples of the human body.
=== Aerobic Exercise === Aerobic exercise is also known as cardio because it is a form of cardiovascular conditioning. This includes exercises such as running, cycling, swimming and rowing. Athletes involved in aerobic exercise are typically looking to increase their endurance. These athletes are training their slow twitch muscle fibers to be better at taking in oxygen and getting it to their muscles. This is done by two mechanisms, glycolysis and aerobic respiration. Anaerobic glycolysis is also referred to as the "short term energy system", and is mostly used for high-intensity training, such as sprinting, and any sports which require quick bursts of speed. Slow twitch muscles are smaller in diameter and are slow to contract. These fibers don't store much glycogen, instead they use lipids and amino acids to generate energy. It has been shown that amino acids contributed around 3% of the total energy expenditure during endurance exercise. With a high concentration of myoglobin that stores oxygen, the slow twitch muscle fibers have plenty of oxygen to function properly. These factors help make slow twitch muscle fibers fatigue resistant so athletes can have endurance in their sport. There are many options for supplements that athletes can take to assist with endurance like glycerol and guarana.
=== United States === One entrepreneur who was quick to spot the advantages of machine-made cigarettes was James Buchanan Duke. Previously a producer of smoking tobacco only, his firm, W. Duke & Sons & Co., entered the cigarette industry in the early 1880s. After installing two Bonsack machines, Duke spent heavily on advertising and sales promotion, and by 1889 his was the largest cigarette manufacturer in the country. The new Bonsack machines were of decisive importance in the rapid, cheap manufacture of all tobacco products but one. Cigars needed slow, laborious hand rolling and were produced in hundreds of small workshops, especially in New York City. In 1890 Duke and the other four major cigarette companies combined to form the American Tobacco Company, a firm that dominated the market and used aggressive tactics on hundreds of small competitors until they sold out to the firm. It was also called the "Tobacco Trust". The trust soon expanded its operations to include cigars, smoking, chewing tobacco and snuff. Among the companies drawn into this organization were the plug manufacturers Liggett & Myers and R. J. Reynolds Tobacco Company, which at the time produced twist and flat plug, and P. Lorillard, an old-line manufacturer of snuff. By 1910 the trust produced 86% of all cigarettes produced in the United States, and 75% to 95% of other forms, but only 14% of cigars produced in the country. At the start of the 20th century, the per capita annual consumption in the U.S.
Leukotriene C4 (LTC4) is a leukotriene. LTC4 has been extensively studied in the context of allergy and asthma. In cells of myeloid origin such as mast cells, its biosynthesis is orchestrated by translocation to the nuclear envelope along with co-localization of cytosolic phospholipase A2 (cPLA2), arachidonate 5-lipoxygenase (5-LO), 5-lipoxygenase-activating protein (FLAP) and LTC4 synthase (LTC4S), which couples glutathione to an LTA4 intermediate. The MRP1 transporter then secretes cytosolic LTC4 and cell surface proteases further metabolize it by sequential cleavage of the γ-glutamyl and glycine residues off its glutathione segment, generating the more stable products LTD4 and LTE4. All three leukotrienes then bind at different affinities to two G-protein coupled receptors: CYSLTR1 and CYSLTR2, triggering pulmonary vasoconstriction and bronchoconstriction. In cells of non-haematopoietic lineage, endoplasmic reticulum (ER) stress and chemotherapy induce LTC4 biosynthesis by transcriptionally upregulating and activating the enzyme microsomal glutathione-S-transferase 2 (MGST2). ER stress and chemotherapy also trigger nuclear translocation of the two LTC4 receptors. Acting in an intracrine manner, LTC4 then elicits nuclear translocation of NADPH oxidase 4 (NOX4), ROS accumulation and oxidative DNA damage. Besides being a potent lipid mediator in asthma and inflammation, LTC4 was reported to be involved in several other diseases, such as allergic airway diseases, dermatological diseases, cardiovascular diseases, liver injury, atherosclerosis and colon cancer.
Sources: en.wikipedia.org
Demand for African slaves did not wane after the decline of the mining industry in the second half of the 18th century. Cattle ranching and foodstuff production proliferated after the population growth, both of which relied heavily on slave labour. 1.7 million slaves were imported to Brazil from Africa from 1700 to 1800, and the rise of coffee in the 1830s further enticed expansion of the slave trade. Brazil was the last country in the Western world to abolish slavery. Forty percent of the total number of slaves brought to the Americas were sent to Brazil.
Catholic Benevolent Legion Catholic Daughters of the Americas Catholic Family Life Insurance - Founded August 1868 by John Martin Henni, the first Archbishop of Milwaukee, as the Family Protective Association. Incorporated in March 1869. Claims to be the oldest Catholic fraternal order, the first to adopt the legal reserve system, first to insure women and children, and first to provide Masses for living and deceased members. Changed name to Catholic Family Life Insurance in 1949. Had 37,000 members in 1967, 47,000 in 54 branches in 1979, 45,000 in 78 branches in 2010. Open to all members of the Catholic faith who were over 18. Headquarters in Milwaukee. Locals called Branches, of which there were 54 in 1979. The national convention is the "Supreme Governing Body", which meets every four years. Sponsors home and foreign missions; invests and makes loans to the building of churches and Catholic schools, hospitals (apparently not loans), a "respect for life" campaign against abortion; and also includes concern for aged and handicapped. Supports many charities such as the "Catholic Rural Life" movement for family farms, Cancer Fund, Heart Fund, Red Cross, and Community Chest. Also sponsors summer camps, social dances, athletic events, family campouts, picnics, and teen parties. Merged with Union Saint-Jean-Baptiste in 1991. Merged with Northern Fraternal Life in 1993. Merged with Catholic Knights on April 1, 2010, into Catholic Financial Life. Catholic Fraternal League - Originally incorporated in Massachusetts on June 19, 1889, as the International Fraternal Alliance.
Chromosome studies are used in the general genetics clinic to determine a cause for developmental delay or intellectual disability, birth defects, dysmorphic features, or autism. Chromosome analysis is also performed in the prenatal setting to determine whether a fetus is affected with aneuploidy or other chromosome rearrangements. Finally, chromosome abnormalities are often detected in cancer samples. A large number of different methods have been developed for chromosome analysis:
where I(iM)is the count rate of the isotope iM of element M. The counting rate of the isotope is dependent on the concentration, XM and the element's isotopic abundance, denoted Ai. Because the primary ion beam determines the secondary ions, Y, that are sputtered, the density of the primary ion beam, db, which is defined as the amount of ions per second per unit of surface area, will affect a portion of the surface area of the sample, S, with an even distribution of the primary ions. Of the sputtered secondary ions, there is only a fraction that will be ionized, Yi. The probability that any ion will be successfully transferred from mass spectrometer to detector is T. The product of Yi and T determines the amount of isotopes that will be ionized, as well as detected, so it is considered the useful yield.
In the late-1970s, Ruben Rausing worked on Operation Flood, a joint venture between the World Food Programme, the World Bank, and Tetra Pak to supply Western milk surplus to Indian households. The company established its Food for Development office in 2000, through which it works with local governments, NGOs and farmers to develop school milk programmes, a cause it has supported since 1962, when the first school milk programme supported by Tetra Pak launched in Mexico. After the 2008 Chinese melamine scandal, the Chinese government tightened regulations on safety and environmental standards, damaging the country's market for packaged milk and infant formula. Tetra Pak had nothing to do with the scandal; however, Tetra Pak China established a training program that was delivered by a food safety school, DVDs, and books, resulting in over 30 farms meeting EU quality standards, according to Tetra Pak China. The effort also included a push to reduce waste by advising customers on recycling and working alongside the World Wildlife Fund to reduce carbon dioxide emissions. The Financial Times indicated this was not a philanthropic act, but a way to establish a future for the company by ensuring there was always a market for their products. In 2015, Tetra Pak in collaboration with DeLavel, signed a five-year agreement with the Dairy Association of China to provide training to 150 Chinese dairy farm managers, providing them with the skills required to run larger-scale dairy farms. It is unclear if this initiative was voluntary or paid for.
Sources: en.wikipedia.org
Liquid chromatography–mass spectrometry is common for identity and purity checks. High-performance liquid chromatography with ultraviolet detection can also be used. Both methods require a suitable reference standard.
The solid is usually kept desiccated at -20 °C or lower and protected from light. Stock solutions are aliquoted to limit freeze–thaw cycles. Aqueous solutions are not generally recommended for long-term storage.
Laws differ by country and by intended use. It is not an approved medicine, and many vendors sell it as a research chemical. Purchasers are responsible for confirming local restrictions.
It is a synthetic research compound that activates REV-ERB nuclear receptors. It is not an approved drug or dietary supplement. Most information comes from cell and animal studies.