Everything below concerns Dietary supplement. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-15. Numbers and descriptions here follow the published literature rather than marketing material.
Trace amounts of NMN have been reported in certain plant foods, including edamame, avocado, broccoli, cucumber, and cabbage. Reported concentrations vary widely because analytical methods differ and food matrices complicate extraction. Endogenous production in cells is generally considered more quantitatively important than dietary intake, though precise human turnover rates are difficult to establish. Commercial NMN for research or consumer products is commonly made through enzymatic synthesis or chemical phosphorylation routes. Regulatory classification differs by country; in some jurisdictions NMN is sold as a supplement, while in others it is treated as a novel food ingredient or restricted substance.
Nicotinamide mononucleotide, abbreviated NMN, is a naturally occurring nucleotide found in cells. Its structure combines a nicotinamide ring, a ribose sugar, and a phosphate group. As an intermediate in the NAD+ salvage pathway, NMN is converted to nicotinamide adenine dinucleotide, a coenzyme central to cellular redox reactions. NAD+ also serves as a substrate for enzymes involved in DNA repair, stress responses, and metabolic regulation. The compound is therefore part of normal cellular biochemistry rather than an exclusively synthetic molecule.
Two enzymatic steps define the canonical route from nicotinamide to NAD+. Nicotinamide phosphoribosyltransferase, known as NAMPT, produces NMN from nicotinamide and phosphoribosyl pyrophosphate. NMN adenylyltransferases, or NMNAT enzymes, then couple NMN with ATP to form NAD+. Whether intact NMN crosses cell membranes efficiently remains an active area of investigation; some studies propose direct transport, while others emphasize extracellular dephosphorylation to nicotinamide riboside followed by uptake. The relative contribution of each route likely depends on cell type, tissue, and experimental conditions.
Analytical measurement of NMN typically uses high-performance liquid chromatography with ultraviolet detection, often at a wavelength near 260 nanometers. Liquid chromatography coupled with tandem mass spectrometry provides greater sensitivity and specificity, especially for biological samples. Nuclear magnetic resonance spectroscopy can confirm structure and detect certain impurities. Purity values reported by suppliers depend on the analytical method, calibration standards, and whether related compounds such as nicotinamide or NAD+ are included in the calculation. Independent verification is useful because supplement labels may not fully describe the tested material.
Regulatory treatment of NMN differs by country and has changed over time. In the United States, the Food and Drug Administration has stated that NMN is excluded from the definition of a dietary supplement because it was investigated as a drug before being marketed as a supplement; enforcement and legal interpretation continue to evolve. In the European Union, NMN may require authorization as a novel food before sale. In Japan, NMN has been marketed in some food products, while it is not approved as a therapeutic drug in major markets. These categories affect labeling, permitted claims, and quality oversight.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C11H15N2O8P | Canonical beta anomer; charge state depends on pH. |
| Molar mass | 334.22 g/mol | Calculated for the neutral formula. |
| CAS Registry Number | 1094-61-7 | Common identifier for beta-nicotinamide mononucleotide. |
| Appearance | White to off-white powder or crystals | Varies with purity, hydration, and polymorphism. |
| Solubility | Freely soluble in water; low solubility in nonpolar solvents | Reported values depend on salt form and temperature. |
Small amounts of NMN occur in some foods, including certain vegetables, fruits, and animal products, though the quantities are generally low and variable. Human cells also synthesize NMN internally from nicotinamide and other precursors. Research interest increased after studies examined whether raising NAD+ levels affects metabolism and aging-related pathways in animals. Evidence in humans remains limited and mixed for many outcomes, and questions about effective absorption, tissue delivery, and long-term effects are still open. Regulatory status differs by country, with some markets treating NMN as a supplement ingredient and others restricting its sale.
Nicotinamide mononucleotide, usually shortened to NMN, is a naturally occurring nucleotide. Its structure consists of a nicotinamide base linked to a ribose sugar that carries a phosphate group. In cells, NMN serves as an intermediate in the salvage pathway that produces nicotinamide adenine dinucleotide, or NAD+. Because NAD+ participates in many oxidation-reduction reactions, NMN sits near central metabolic processes. The compound is not a drug in most jurisdictions and is discussed mainly in biochemistry and nutrition research.
Quality control for NMN focuses on identity, purity, residual solvents, heavy metals, and microbial limits. Because the molecule can absorb water, moisture content and packaging are relevant to shelf life. Suppliers may provide certificates of analysis, but independent verification is often needed for research or commercial use. The long-term stability of different crystal forms, salt forms, and formulations is not fully characterized in the public literature. Some degradation products and their effects on product performance remain open questions.
As a commercial ingredient, nicotinamide mononucleotide is commonly supplied as a powder or capsule. Its stability depends on temperature, moisture, pH, and light exposure. Hydrolytic and thermal degradation can increase over time, so manufacturers and laboratories often store material cold and dry. Purity is typically assessed with chromatographic methods, and identity can be confirmed by mass spectrometry. Published stability data for specific finished products remain limited. More data would help define shelf life under real-world conditions.
==== Light-enhanced ==== Plasmonic effects have been studied quite extensively. Until recently, there have not been studies investigating the oxidative catalytic enhancement of a nanostructure via excitation of its surface plasmon resonance. The defining feature for enhancing the oxidative catalytic ability has been identified as the ability to convert a beam of light into the form of energetic electrons that can be transferred to adsorbed molecules. The implication of such a feature is that photochemical reactions can be driven by low-intensity continuous light coupled with thermal energy. The coupling of low-intensity continuous light and thermal energy has been performed with silver nanocubes. The important feature of silver nanostructures that are enabling for photocatalysis is their nature to create resonant surface plasmons from light in the visible range. The addition of light enhancement enabled the particles to perform to the same degree as particles that were heated up to 40 K greater. This is a profound finding when noting that a reduction in temperature of 25 K can increase the catalyst lifetime by nearly tenfold, when comparing the photothermal and thermal process.
Continuous positive airway pressure (CPAP) is effective for both moderate and severe disease. It is the most common treatment for obstructive sleep apnea. Variable positive airway pressure (VPAP) (also known as bilevel (BiPAP or BPAP)) uses an electronic circuit to monitor the patient's breathing and provides two different pressures, a higher one during inhalation and a lower pressure during exhalation. This system is more expensive and is sometimes used with patients who have other coexisting respiratory problems or who find breathing out against an increased pressure to be uncomfortable or disruptive to their sleep. Nasal EPAP, which is a bandage-like device placed over the nostrils that utilizes a person's own breathing to create positive airway pressure to prevent obstructed breathing. Automatic positive airway pressure, also known as "Auto CPAP", incorporates pressure sensors and monitors the person's breathing. A 5% reduction in weight among those with moderate to severe OSA may decrease symptoms similarly to CPAP. Encouraging people with moderate to severe OSA to use CPAP devices can be challenging, as their use often requires a behavioural change in sleeping habits. 8% of people who use CPAP devices stop using them after the first night, and 50% of people with moderate to severe OSA stop using their devices in the first year. Educational initiatives and supportive interventions to help improve compliance with CPAP therapy have been shown to improve the length of time people who need CPAP therapy use their devices.
== Research == Soft-tissue sarcoma research requires significant effort due to its rarity; successful research requires substantial collaboration. Year by year, the medical field is learning that the various types cannot be lumped together and each sarcoma needs to be considered a different type of cancer. As a novel form of treatment used in other cancers, immunotherapy may have a role in treating soft-tissue sarcomas like alveolar soft part sarcoma and pleomorphic undifferentiated sarcoma. However, as of 2023, only alveolar soft part sarcoma has a regulatory approval for such an agent, in this case atezolizumab.
=== Histones === Daly was particularly interested in nuclear proteins. She developed methods for the fractionation of nuclear material and the determination of its composition. It was essential to separate cellular material into all of its components, without destroying or losing any of them. She studied histones, proteins found in cell nuclei, and was able to show the amino acid composition of various histone fractions. Her studies of histones with Mirsky provided evidence for lysine-rich histones, in contrast to the arginine-rich histones described by Albrecht Kossel. Histones have since been shown to be important in gene expression. Daly's work on histones is now considered fundamental.
Sources: en.wikipedia.org
The δ13C and δ34S of coexisting carbonate minerals and sulfides can be used to determine the pH and oxygen fugacity of the ore-bearing fluid during ore formation. Scientists measure the sulfur isotopes of minerals in rocks and sediments to study the redox conditions in past oceans. Sulfate-reducing bacteria in marine sediment fractionate sulfur isotopes as they take in sulfate and produce sulfide. Prior to the 2010s, it was thought that sulfate reduction could fractionate sulfur isotopes up to 46 permil and fractionation larger than 46 permil recorded in sediments must be due to disproportionation of sulfur compounds in the sediment. This view has changed since the 2010s as experiments showed that sulfate-reducing bacteria can fractionate to 66 permil. As substrates for disproportionation are limited by the product of sulfate reduction, the isotopic effect of disproportionation should be less than 16 permil in most sedimentary settings. In forest ecosystems, sulfate is derived mostly from the atmosphere; weathering of ore minerals and evaporites contribute some sulfur. Sulfur with a distinctive isotopic composition has been used to identify pollution sources, and enriched sulfur has been added as a tracer in hydrologic studies. Differences in the natural abundances can be used in systems where there is sufficient variation in the 34S of ecosystem components. Rocky Mountain lakes thought to be dominated by atmospheric sources of sulfate have been found to have measurably different 34S values than lakes believed to be dominated by watershed sources of sulfate.
Ubiquitin (originally, ubiquitous immunopoietic polypeptide) was first identified in 1975 as an 8.6 kDa protein expressed in all eukaryotic cells. The basic functions of ubiquitin and the components of the ubiquitylation pathway were elucidated in the early 1980s at the Technion by Aaron Ciechanover, Avram Hershko, and Irwin Rose for which the Nobel Prize in Chemistry was awarded in 2004. The ubiquitylation system was initially characterised as an ATP-dependent proteolytic system present in cellular extracts. A heat-stable polypeptide present in these extracts, ATP-dependent proteolysis factor 1 (APF-1), was found to become covalently attached to the model protein substrate lysozyme in an ATP- and Mg2+-dependent process. Multiple APF-1 molecules were linked to a single substrate molecule by an isopeptide linkage, and conjugates were found to be rapidly degraded with the release of free APF-1. Soon after APF-1-protein conjugation was characterised, APF-1 was identified as ubiquitin. The carboxyl group of the C-terminal glycine residue of ubiquitin (Gly76) was identified as the moiety conjugated to substrate lysine residues.
== Function == PAPPA encodes a secreted metalloproteinase which cleaves insulin-like growth factor–binding proteins (IGFBPs). PAPPA's proteolytic function is activated upon collagen binding. It is thought to be involved in local proliferative processes such as wound healing and bone remodeling. Low plasma level of this protein has been suggested as a biochemical marker for pregnancies with aneuploid fetuses (fetuses with an abnormal number of chromosomes). For example, low PAPPA may be commonly seen in prenatal screening for Down syndrome. Low levels may alternatively predict issues with the placenta, resulting in adverse complications such as intrauterine growth restriction, preeclampsia, placental abruption, premature birth, or fetal death. This enzyme catalyses the following chemical reaction: Cleavage of the Met135-Lys bond in insulin-like growth factor binding protein (IGFBP)-4, and the Ser143-Lys bond in IGFBP-5 This enzyme belongs to the peptidase family M43.
Protein L was first isolated from the surface of bacterial species Peptostreptococcus magnus and was found to bind immunoglobulins through L chain interaction, from which the name was suggested. It consists of 719 amino acid residues. The molecular weight of protein L purified from the cell walls of Peptostreptoccus magnus was first estimated as 95kD by SDS-PAGE in the presence of reducing agent 2-mercaptoethanol, while the molecular weight was determined to 76kD by gel chromatography in the presence of 6 M guanidine HCl. Protein L does not contain any interchain disulfide loops, nor does it consist of disulfide-linked subunits. It is an acidic molecule with a pI of 4.0. Unlike protein A and protein G, which bind to the Fc region of immunoglobulins (antibodies), protein L binds antibodies through light chain interactions. Since no part of the heavy chain is involved in the binding interaction, Protein L binds a wider range of antibody classes than protein A or G. Protein L binds to representatives of all antibody classes, including IgG, IgM, IgA, IgE and IgD. Single chain variable fragments (scFv) and Fab fragments also bind to protein L. Despite this wide binding range, protein L is not a universal antibody-binding protein. Protein L binding is restricted to those antibodies that contain kappa light chains. In humans and mice, most antibody molecules contain kappa (κ) light chains and the remainder have lambda (λ) light chains. Protein L is only effective in binding certain subtypes of kappa light chains.
A post hoc analysis from a randomized, placebo-controlled, multi-centre study carried out at 11 secondary care centres, as well as a longitudinal single-centre study on pregnant women in Norway, also determined that metformin had no effect on maternal androgens in pregnancies occurring in the setting of PMOS. One systemic review suggested that polymorphisms in the vitamin D receptor gene are associated with the prognosis of polyendocrine metabolic ovarian syndrome, though this is based on small sample sizes and is debated. Studies have shown benefits for vitamin D supplementation in women with vitamin D deficiency and PMOS. Hyperinsulinemia can increase the production of androgens in the ovaries. One context in which this occurs is HAIR-AN syndrome, a rare subtype of PMOS.
Sources: en.wikipedia.org
Works by Marguerite Yourcenar at Open Library Petri Liukkonen. "Marguerite Yourcenar". Books and Writers. Stockinger, Jacob (3 March 2004) [2002]. "Yourcenar, Marguerite (1903–1987)". In Summers, Claude J. (ed.). glbtq: An encyclopedia of gay, lesbian, bisexual, transgender, and queer culture. Chicago: glbtq, Inc. Archived from the original on 16 January 2009. Marguerite Yourcenar et Suzanne Lilar : plus qu’une rencontre, une complicité by Michèle Goslar English translations of Marguerite Yourcenar by Walter Jacob Kaiser, Catalogue of correspondence and manuscripts concerning Walter Kaiser's English translation of works by French writer Marguerite Yourcenar, Houghton Library, Harvard University Accueil
Chymotrypsin is a serine endopeptidase that is present in pancreatic juice and helps the hydrolysis of proteins and peptide. It catalyzes the hydrolysis of peptide bonds in L-isomers of tyrosine, phenylalanine, and tryptophan. In the active site of this enzyme, three amino acid residues work together to form a catalytic triad which makes up the catalytic site. In chymotrypsin, these residues are Ser-195, His-57 and Asp-102. The mechanism of chymotrypsin can be divided into two phases. First, Ser-195 nucleophilically attacks the peptide bond carbon in the substrate to form a tetrahedral intermediate. The nucleophilicity of Ser-195 is enhanced by His-57, which abstracts a proton from Ser-195 and is in turn stabilised by the negatively charged carboxylate group (RCOO−) in Asp-102. Furthermore, the tetrahedral oxyanion intermediate generated in this step is stabilised by hydrogen bonds from Ser-195 and Gly-193. In the second stage, the R'NH group is protonated by His-57 to form R'NH2 and leaves the intermediate, leaving behind the acylated Ser-195. His-57 then acts as a base again to abstract one proton from a water molecule. The resulting hydroxide anion nucleophilically attacks the acyl-enzyme complex to form a second tetrahedral oxyanion intermediate, which is once again stabilised by H bonds. In the end, Ser-195 leaves the tetrahedral intermediate, breaking the CO bond that connected the enzyme to the peptide substrate. A proton is transferred to Ser-195 through His-57, so that all three amino acid return to their initial state.
In eukaryotes, ribosomes are present in mitochondria (sometimes called mitoribosomes) and in plastids such as chloroplasts (also called plastoribosomes). They also consist of large and small subunits bound together with proteins into one 70S particle. These ribosomes are similar to those of bacteria and these organelles are thought to have originated as symbiotic bacteria. Of the two, chloroplastic ribosomes are closer to bacterial ones than mitochondrial ones are. Many pieces of ribosomal RNA in the mitochondria are shortened, and in the case of 5S rRNA, replaced by other structures in animals and fungi. In particular, Leishmania tarentolae has a minimalized set of mitochondrial rRNA. In contrast, plant mitoribosomes have both extended rRNA and additional proteins as compared to bacteria, in particular, many pentatricopetide repeat proteins. The cryptomonad and chlorarachniophyte algae may contain a nucleomorph that resembles a vestigial eukaryotic nucleus. Eukaryotic 80S ribosomes may be present in the compartment containing the nucleomorph.
During the Second World War, Nazi Germany effectively enslaved about 12 million people, both those considered undesirable and citizens of conquered countries, with the avowed intention of treating these Untermenschen (sub-humans) as a permanent slave-class of inferior beings who could be worked until they died, and who possessed neither the rights nor the legal status of members of the Aryan race. Besides Jews, the harshest deportation and forced labour policies were applied to the populations of Poland, Belarus, Ukraine, and Russia. By the end of the war, half of Belarus' population had been killed or deported.
== Gender gap == The World Economic Forum's Global Gender Gap Report 2018 attempts to capture the magnitude of gender-based disparities in the world's states and track progress over time. In the 2018 report, gender disparities were investigated in 149 nations. Thailand ranked 73 of 149 (1=fewest disparities). It ranked very low (130) in women's political participation. Thailand's ASEAN neighbours ranked: Philippines, 8; Laos, 26; Singapore, 67; Vietnam, 77; Indonesia, 85; Myanmar, 88; Brunei, 90; Cambodia, 93; Malaysia, 101. The World Economic Forum's Global Gender Gap Report 2014: Thailand ranked 61 of 142 nations.
Sources: en.wikipedia.org
NMN is nicotinamide mononucleotide, a nucleotide intermediate in NAD+ metabolism. It occurs naturally in cells and can also be produced synthetically for research or commercial use. Its name reflects its composition: nicotinamide, ribose, and a phosphate group.
NMN is a direct precursor in the NAD+ salvage pathway. NMNAT enzymes convert NMN and ATP into NAD+, a coenzyme used in many cellular reactions. This relationship makes NMN a focus of studies on NAD+ metabolism.
Small amounts of NMN have been reported in some plant foods, but measured levels vary and are not consistently quantified. Dietary contribution is generally considered minor compared with endogenous production. Food-matrix effects make accurate analysis difficult.
Solid NMN is commonly stored frozen at about minus 20 degrees Celsius, sealed against moisture, and protected from light. Solutions are typically prepared fresh because they can degrade more quickly. Specific storage conditions can vary by supplier and intended use.