A practical reference on circadian rhythm: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-06-01. 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.
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.
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.
| 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. |
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.
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.
== Alternatives == In general, COBRA is often combined with other DNA methylation analyses and is frequently used in the initial screening of a loci of interest. If COBRA suggests altered methylation patterns, then more rigorous, labor-intensive techniques can be applied, such as bisulfite sequencing or MeDIP. Also PacBio sequencing can be used to detect DNA methylation.
== See also == Charcot–Marie–Tooth disease classifications Christina's World – 1948 painting by Andrew Wyeth Hereditary motor and sensory neuropathies Hereditary motor neuropathies Low copy repeats Palmoplantar keratoderma and spastic paraplegia
For instance, in Commission v Italy the Court of Justice held that Italy had breached a duty under the Treaties, both by failing to operate a scheme to pay farmers a premium to slaughter cows (to reduce dairy overproduction), and by reproducing the rules in a decree with various additions. "Regulations", held the Court of Justice, "come into force solely by virtue of their publication" and implementation could have the effect of "jeopardising their simultaneous and uniform application in the whole of the Union". On the other hand, some Regulations may themselves expressly require implementing measures, in which case those specific rules should be followed.
In 2024, the National Institute for Space Research (INPE) identified a 100% increase in the number of fires compared to the same period in 2023, with 50% of these fires recorded in the Amazon, and 32% in the Cerrado. In October 2024, MapBiomas and Amazon Environmental Research Institute (IPAM) reported that the burned area was 150% larger than in 2023, equivalent to the size of the state of Roraima, through the MapBiomas Fire Monitor. According to the Copernicus Programme, Brazil broke a record for carbon emissions, releasing 180 megatonnes of carbon into the atmosphere, largely due to the increase in fires, bringing it close to that recorded in 2007, when the country broke the previous record, with the states of Amazonas and Mato Grosso being the biggest emitters. According to INPE, in 2024, Brazil had the highest number of fires of the century.
Sources: en.wikipedia.org
With the dissolution of the Napoleonic Kingdom of Italy in 1814, following the final fall of Emperor Napoleon I after the Battle of Waterloo, Ferdinand's son, Francis IV, assumed the rule as Duke of Modena. In December 1815 he obtained the transfer from his mother Maria Beatrice d'Este of the former imperial fiefs in Lunigiana, not reconstituted by the Congress of Vienna and bestowed upon her. On her death in 1829, he also inherited the Duchy of Massa and Carrara, which she had in turn received from her mother Maria Teresa Cybo-Malaspina, since Salic Law was derogated there by special imperial investiture. In the course of the Italian unification period in the 1830s-60s, the "Austria-Este" dukes were briefly ousted in the revolutions of 1831 and 1848, but soon returned. During the Second Italian War of Independence (April to July 1859) following the Battle of Magenta, the last Duke Francis V was again forced to flee, this time permanently. In December, Modena joined with Tuscany and Parma to form the "United Provinces of Central Italy", which were annexed to the growing Kingdom of Sardinia in March 1860, which led the Italian unification movement, which further led to the proclamation of the Kingdom of Italy in 1861.
Eddy copyrighted her book, then called The Science of Life, in July 1874. Three of her students, George Barry, Elizabeth Newhall and Daniel Spofford, paid a Boston printer, W. F. Brown and Company, $2,200 to produce the first edition. The printer began work in September 1874, but stopped whenever the advance payment ran out, so progress was slow. The book—Science and Health by Mary Baker Glover, with eight chapters and 456 pages—finally appeared on October 30, 1875, published in the name of the Christian Science Publishing Company. The book was positively received by Amos Bronson Alcott, who in 1876 wrote to Eddy that she had "reaffirm[ed] in modern phrase the Christian revelations," and that he was pleased it had been written by a woman. The printer's proofreading had been poor. Martin Gardner called the first edition a "chaotic patchwork of repetitious, poorly paragraphed topics," with spelling, punctuation and grammatical mistakes. Eddy changed printers for the second edition, which was also poorly proofread, and for the third edition in 1881 switched again, this time to John Wilson & Sons, University Press, Cambridge, MA. John Wilson and his successor, William Dana Orcutt, continued to print the book until after Eddy's death. To the 6th edition in 1883, Eddy added with a Key to the Scriptures (later retitled with Key to the Scriptures), a 20-page glossary containing her definitions of biblical terms. The book sold 15,000 copies between 1875 and 1885. In August 1885, on the advice of John Wilson, she hired one of his proofreaders, the Rev.
Square pyramidal for five-coordination Capped octahedral or capped trigonal prismatic for seven-coordination Dodecahedral or bicapped trigonal prismatic for eight-coordination Capped square antiprismatic for nine-coordination To distinguish between the alternative coordinations for five-coordinated complexes, the τ geometry index was invented by Addison et al. This index depends on angles by the coordination center and changes between 0 for the square pyramidal to 1 for trigonal bipyramidal structures, allowing to classify the cases in between. This system was later extended to four-coordinated complexes by Houser et al. and also Okuniewski et al. In systems with low d electron count, due to special electronic effects such as (second-order) Jahn–Teller stabilization, certain geometries (in which the coordination atoms do not follow a points-on-a-sphere pattern) are stabilized relative to the other possibilities, e.g. for some compounds the trigonal prismatic geometry is stabilized relative to octahedral structures for six-coordination.
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.
Liquid chromatography with mass spectrometry is a common approach. Ultraviolet detection and nuclear magnetic resonance can support identification when suitable standards are available.