A practical reference on analytical standard: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-07-24. Anything still debated is marked as such rather than presented as settled.
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.
| 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.
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.
. Aston's early model of nuclear structure (prior to the discovery of the neutron) postulated that the electromagnetic fields of closely packed protons and electrons in the nucleus would interfere and a fraction of the mass would be destroyed. A low packing fraction is indicative of a stable nucleus.
Examples of botanically classified fruit that are typically called vegetables include cucumber, pumpkin, and squash or other winter squashes (all are cucurbits); beans, peanuts, and peas (all legumes); and corn, eggplant, bell pepper (or sweet pepper), and tomato. Many spices are fruits, botanically speaking, including black pepper, chili pepper, cumin and allspice. In contrast, rhubarb is often called a fruit when used in making pies, but the edible produce of rhubarb is actually the leaf stalk or petiole of the plant. Botanically, a cereal grain, such as corn, rice, or wheat is a kind of fruit (termed a caryopsis). However, the fruit wall is thin and fused to the seed coat, so almost all the edible grain-fruit is actually a seed.
Temperature If the relative humidity is kept constant, the higher the temperature, the higher the drying rate. Temperature influences the drying rate by increasing the moisture holding capacity of the air, as well as by accelerating the diffusion rate of moisture through the wood. The actual temperature in a drying kiln is the dry-bulb temperature (usually denoted by Tg), which is the temperature of a vapour-gas mixture determined by inserting a thermometer with a dry bulb. On the other hand, the wet-bulb temperature (TW) is defined as the temperature reached by a small amount of liquid evaporating in a large amount of an unsaturated air-vapour mixture. The temperature sensing element of this thermometer is kept moist with a porous fabric sleeve (cloth) usually put in a reservoir of clean water. A minimum air flow of 2 m/s is needed to prevent a zone of stagnant damp air formation around the sleeve. Since air passes over the wet sleeve, water is evaporated and cools the wet-bulb thermometer. The difference between the dry-bulb and wet-bulb temperatures, the wet-bulb depression, is used to determine the relative humidity from a standard hygrometric chart. A higher difference between the dry-bulb and wet-bulb temperatures indicates a lower relative humidity. For example, if the dry-bulb temperature is 100 °C and wet-bulb temperature 60 °C, then the relative humidity is read as 17% from a hygrometric chart.
Gusev and his staff appealed to Moscow for more aid to FAPLA, particularly strike aircraft, for another offensive; this request was granted. In what had become an annual practice, an estimated billion dollars' worth of arms was flown into Luanda by Soviet Antonov An-24 flights, as many as 12 per day for a six-month period. The equipment was offloaded in the capital and transferred to Angolan Ilyushin Il-76s, which in turn flew them directly to the front. To FAPLA, the experience of planning and executing an operation of such massive proportions was relatively new, but the Soviet military mission was convinced that a decade of exhaustive training on its part had created an army capable of undertaking a complex multi-divisional offensive. The Angolan brigade commanders had repeatedly expressed reservations about splitting the force and fighting on two fronts, arguing that a single assault on Mavinga would be more linear and sufficient. FAPLA's Cuban advisers objected on the grounds that South Africa might intervene on behalf of its erstwhile ally. "Don't get into such wasting, costly, and finally pointless offensives," Castro had vented to Gusev's staff. "And count us out if you do." General Arnaldo Ochoa, the senior Cuban military officer in Angola, also protested that the tactics FAPLA were being forced to adopt were more applicable to combat operations in central Europe than an offensive against an irregular fighting force on the broken African terrain.
Sources: en.wikipedia.org
=== Structure === Polyphenols, such as lignin, are larger molecules (macromolecules). Their upper molecular weight limit is about 800 daltons, which allows for the possibility to rapidly diffuse across cell membranes so that they can reach intracellular sites of action or remain as pigments once the cell senesces. Hence, many larger polyphenols are biosynthesized in situ from smaller polyphenols to non-hydrolyzable tannins and remain undiscovered in the plant matrix. Most polyphenols contain repeating phenolic moieties of pyrocatechol, resorcinol, pyrogallol, and phloroglucinol connected by esters (hydrolyzable tannins) or more stable C-C bonds (nonhydrolyzable condensed tannins). Proanthocyanidins are mostly polymeric units of catechin and epicatechin.
=== 16 May === Two people were killed in Russian attacks in Kharkiv Oblast. One person was killed in a separate attack in Kherson Oblast. Ukrainian media reported that the HUR launched a drone attack on a weapons manufacturing plant in Russia's Tula Oblast. President Zelenskyy arrived in Kharkiv to meet with the military leadership, saying that the situation in Kharkiv Oblast was "generally under control" but the area remained "extremely difficult". A police official in Kharkiv said that up to 40 civilians in Vovchansk who attempted to flee shelling were captured by Russian forces and were reportedly imprisoned in basements where they are interrogated by alleged FSB agents. According to Ukrainian Interior Minister Ihor Klymenko, Russian soldiers in Vovchansk executed a civilian prisoner after he refused to obey orders and attempted to flee. Police opened a criminal investigation on the grounds of violations of laws of war. Ukrainian soldiers in the Kharkiv front reported that they had "never seen anything close to the number of Lancets (drones) flying" compared to earlier battles. The ISW assessed that the "tempo of Russian offensive operations in the area continues to decrease".
== Organic heterocycles and polymers == Radical cations figure prominently in the chemistry and properties of conducting polymers. Such polymers are formed by the oxidation of heterocycles to give radical cations, which condense with the parent heterocycle. For example, polypyrrole is prepared by oxidation of pyrrole using ferric chloride in methanol:
==== Other androgenic and antiandrogenic actions ==== A paradoxical effect occurs with certain prostate cancer cells which have genetic mutations in their ARs. These altered ARs can be activated, rather than inhibited, by CPA. In such cases, withdrawal of CPA may result in a reduction in cancer growth, rather than the reverse. This is known as antiandrogen withdrawal syndrome. CPA may also have a slight direct inhibitory effect on 5α-reductase, though the evidence for this is sparse and conflicting. Most studies however suggest that CPA does not produce important inhibition of 5α-reductase. The combination of birth control pills containing CPA with finasteride, a well-established, selective 5α-reductase inhibitor, has been found to result in significantly improved effectiveness in the treatment of hirsutism relative to CPA-containing birth control pills alone. In addition to its AR antagonistic activity and suppression of gonadal sex-hormone production, high-dose CPA has been found to suppress the levels of the adrenal androgen dehydroepiandrosterone sulfate (DHEA-S), which is due to exertion of negative feedback by CPA on adrenocorticotropic hormone (ACTH) secretion via the glucocorticoid activity of CPA.
Prior to a law change in 2006, babies of non-citizens born in New Zealand were entitled to New Zealand citizenship. 18 February: Government Statistician Mark Sowden confirms he will resign on 30 March after an inquiry by the Public Service Commission into data breach allegations at Manurewa Marae in 2023 criticised Statistics New Zealand's handling of personal information and management of conflicts of interest. Torrential rain leads to flash flooding in parts of Otago including Beaumont. 19 February: The New Zealand Government establishes a NZ$2 million dual purpose fund to honour children who died in care and were buried in unmarked graves. A group of abuse survivors picket the Accident Compensation Corporation's Christchurch office, demanding the company reform eligibility coverage policies for abuse survivors. 20 February: Associate Immigration Minister Chris Penk uses his discretionary powers to grant Davan Kumar a residency visa but upholds the deportation order against his overstayer parents. Australian and New Zealand Defence Ministers Richard Marles and Judith Collins confirm that the Australian and New Zealand Defence Forces are monitoring three Chinese warships that are sailing through international waters near Sydney. New Zealand Media and Entertainment confirms plans to layoff several senior reporters and create a new Free ad-supported streaming television (FAST) channel. 21 February: Flights between Australia and New Zealand are diverted after the Chinese Navy conducts live fire drills using warships 340 nautical miles east of Sydney, in international waters.
Sources: en.wikipedia.org
== Self-assembled monolayers on solid substrates == Self-assembled monolayers (SAMs) are made of a layer of organic molecules which forms naturally as an ordered lattice on the surface of a desired substrate. Their molecules in the lattice have connections chemically at one end (head group), while the other end (end group) creates the exposed surface of the SAM. Many types of SAMs can be formed. For example: thiols form SAMs on gold, silver, copper, or on some compound semiconductors such as InP and GaAs. By changing the tail group of the molecules, different surface properties can be obtained; therefore SAMs can be used to render surfaces hydrophobic or hydrophilic as well as change surface states of semiconductor. With self-assembly, positioning of SAMs is used to define chemical system precisely to find the target location in a molecular-inorganic device. With this characteristic, SAMs is a good candidates for molecular electronic devices such as use SAMs to build electronic devices and maybe the circuits is an intriguing prospect. Because of their ability to provide the basis for very high-density data storage and high-speed devices.
=== Craniofacial syndromes === Of substantial recent interest is the idea that there is a general human tendency towards developing short lower jaws (neoteny) is a major cause of OSA through a combined condition called glossoptosis. The posterior "normal" tongue is displaced backwards by a smaller "abnormal" anterior tongue and lower jaw. In much the same way, a narrow upper jaw will also contribute to OSA due to its relation to airway volume. A narrower upper jaw results in narrower nasal passages and a narrower throat; this also appears to be why so many OSA patients experience nasal congestion, especially while lying down. Maxillofacial surgeons see many effects of small lower jaws, including crowded teeth, malocclusions, as well as OSA – all of which are treatable by surgical operations that increase and normalise jaw size. Operations such as custom BIMAX, GenioPaully, and IMDO (in adolescence) offer a valid medical option that replaces all traditional forms of OSA treatment – including CPAP, Mandibular Advancement Splints, tonsillectomy, and UPPP. There are patterns of unusual facial features that occur in recognizable syndromes. Some of these craniofacial syndromes are genetic, and others are from unknown causes. In many craniofacial syndromes, unusual features involve the nose, mouth, and jaw, or resting muscle tone, and put the individual at risk for OSA. Down syndrome is one such syndrome. In this chromosomal abnormality, several features combine to make the presence of obstructive sleep apnea more likely.
== Contraindications == Contraindications of anastrozole include hypersensitivity to anastrozole or any other component of anastrozole formulations, pregnancy, and breastfeeding. Hypersensitivity reactions to anastrozole including anaphylaxis, angioedema, and urticaria have been observed.
== History == Oxytocin's uterine-contracting properties were discovered by British pharmacologist Henry Hallett Dale in 1906. Oxytocin's milk ejection property was described by Ott and Scott in 1910 and by Schafer and Mackenzie in 1911. Oxytocin was the first polypeptide hormone to be sequenced or synthesized. Du Vigneaud was awarded the Nobel Prize in 1955 for his work.
inverted repeat A nucleotide sequence followed downstream on the same strand by its own reverse complement. The initial sequence and the reverse complement may be separated by any number of nucleotides, or may be immediately adjacent to each other; in the latter case, the composite sequence is also called a palindromic sequence. Inverted repeats are self-complementary by definition, a property which involves them in many biological functions and dysfunctions. Contrast direct repeat.
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.