Everything below concerns NAD+. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-06-30. Numbers and descriptions here follow the published literature rather than marketing material.
Beyond redox chemistry, NAD+ serves as a substrate for enzymes that transfer ADP-ribose or remove acetyl groups. Sirtuins, PARPs, and CD38-family enzymes consume NAD+ and produce nicotinamide and ADP-ribose-related products. These reactions link NAD+ availability to DNA repair, chromatin modification, and cellular signaling. Because the molecule is central to energy metabolism and regulation, changes in its concentration are studied in aging, immunity, and metabolic research. The balance between synthesis and consumption varies by tissue, developmental stage, and physiological state.
In humans, NAD+ can be synthesized from nicotinic acid, nicotinamide, nicotinamide riboside, and tryptophan through overlapping pathways. The salvage pathway recycles nicotinamide back to NAD+ and is often considered a major route in many tissues. Dietary precursors and intracellular recycling both contribute to the pool, but the quantitative importance of each source remains an active research question. NAD+ levels are not uniform across organs or cell compartments. Measurements in blood do not necessarily reflect concentrations inside tissues.
NAD+ is a dinucleotide composed of nicotinamide, ribose, and adenine linked by phosphate groups. Its full name is nicotinamide adenine dinucleotide, with "+" denoting the oxidized form. The molecule acts as a coenzyme in redox reactions, cycling between NAD+ and NADH. In cells, it participates in electron transfer during glycolysis, the citric acid cycle, and oxidative phosphorylation. It is distinct from NADP+, which carries an additional phosphate group and supports different biosynthetic reactions.
Quality control for NAD+ materials typically combines identity, purity, and water content checks. Identity may be confirmed by ultraviolet spectrum, retention time in chromatography, or mass accuracy, while purity is assessed by HPLC peak area or quantitative nuclear magnetic resonance. Residual water and solvents can affect molar calculations and enzyme assays, so Karl Fischer titration or thermogravimetric analysis may be used. Commercial materials vary in grade and counterion form, and published methods should specify the exact salt or hydrate when reporting concentrations. Regulatory status depends on intended use, with research reagents, dietary ingredients, and clinical products treated under different frameworks.
Quantification of NAD+ in biological samples usually relies on separation techniques coupled to sensitive detection. High-performance liquid chromatography with ultraviolet detection can measure the oxidized form by its absorbance near 260 nm, while mass spectrometry provides greater specificity and can distinguish NAD+ from close analogs. Enzymatic cycling assays use coupled dehydrogenase reactions to amplify signal and estimate NAD+ concentrations in cell or tissue extracts. Because NAD+ and NADH interconvert rapidly, sample preparation must quench metabolism quickly and preserve the redox state before analysis.
The stability of NAD+ depends on pH, temperature, light exposure, and the presence of degradative enzymes. Aqueous solutions are generally more stable under mildly acidic to neutral conditions and degrade faster under alkaline conditions or prolonged heat. The solid is hygroscopic and should be stored desiccated, often frozen, and protected from repeated freeze-thaw cycles. In laboratory handling, aliquots reduce repeated temperature changes, and chelating agents may limit metal-catalyzed hydrolysis in some buffers. These practices matter because even small amounts of NADH or hydrolysis products can interfere with quantitative assays.
| Property | Value | Notes |
|---|---|---|
| Common name | Nicotinamide adenine dinucleotide (oxidized) | Often shortened to NAD+ |
| Chemical class | Dinucleotide | Contains nicotinamide and adenine moieties |
| Molecular formula | C21H27N7O14P2 | Free acid form; charge depends on pH |
| Molar mass | About 663.43 g/mol | Calculated for C21H27N7O14P2 |
| CAS number | 53-84-9 | Common identifier for beta-NAD+ |
Related compounds include NADH, the reduced form, and NADP+, which carries an additional phosphate group. NADP+ and NADPH often serve in biosynthetic and antioxidant reactions, while NAD+ and NADH are more associated with energy-yielding catabolism. Nicotinamide, nicotinic acid, and nicotinamide riboside are precursors that can enter salvage pathways. The exact contribution of dietary precursors to tissue NAD+ pools is an area of active investigation. Some studies measure labeled precursors to trace those routes.
NAD+ is the oxidized form of nicotinamide adenine dinucleotide, a coenzyme built from two nucleotides joined by a phosphate linkage. One nucleotide carries adenine, and the other carries nicotinamide; the plus sign denotes a formal positive charge on the nicotinamide ring, not a free proton. In cells, NAD+ and its reduced partner NADH form a reversible redox pair. That pair participates in electron transfer reactions throughout metabolism. The abbreviation NAD+ is common in biochemistry, while NAD(H) sometimes denotes the combined pool.
Beyond redox chemistry, NAD+ is consumed as a substrate by enzymes that transfer ADP-ribose or remove acetyl groups. Sirtuins use NAD+ in deacylation reactions, poly(ADP-ribose) polymerases use it in DNA damage responses, and CD38 hydrolases convert it to signaling metabolites. Because these enzymes compete for the same pool, changes in NAD+ availability can influence multiple cellular processes. The relative contribution of each consumption route differs by cell type and condition, and precise quantitative links remain an active area of study.
Research on NAD+ spans biochemistry, aging biology, and metabolism. Studies often examine how NAD+ levels change with age, diet, exercise, or disease states, and whether precursor supplementation alters those levels. Findings in animal models do not automatically translate to humans, and measurement methods vary across studies. Questions about tissue-specific effects, long-term consequences, and causal relationships remain open. NAD+ itself is not established as a single therapeutic agent with a broad clinical role.
Nicotinamide adenine dinucleotide, abbreviated NAD+, is a dinucleotide composed of two nucleotides joined by phosphate groups. One nucleotide contains adenine; the other contains nicotinamide. The molecule exists in oxidized (NAD+) and reduced (NADH) forms, and the reversible hydride transfer between them underlies many metabolic oxidation-reduction reactions. In cells, NAD+ serves as an electron acceptor in pathways such as glycolysis, the citric acid cycle, and oxidative phosphorylation. Its concentration and redox ratio vary by compartment, tissue, and metabolic state.
Nicotinamide adenine dinucleotide, commonly abbreviated NAD+, is a dinucleotide coenzyme built from an adenine nucleotide and a nicotinamide nucleotide joined by a pyrophosphate linkage. Its oxidized form carries a positive charge on the nicotinamide ring, while the reduced form, NADH, carries a hydride equivalent. The molecule participates in hundreds of oxidoreductase reactions, where it accepts or donates electrons and protons. Because it can cycle between oxidized and reduced states without net consumption, NAD+ functions as a reusable electron carrier rather than a fuel molecule.
In glycolysis, the tricarboxylic acid cycle, and fatty acid oxidation, NAD+ is reduced to NADH at specific dehydrogenase steps. NADH then delivers electrons to the mitochondrial electron transport chain, mainly at complex I, supporting oxidative phosphorylation and ATP production. The balance between NAD+ and NADH, often expressed as a ratio, influences metabolic flux and redox homeostasis in different cellular compartments. Cytosolic and mitochondrial pools are connected but not identical, and their ratios can differ substantially because of compartment-specific enzymes and transport systems.
== Function == Ceruloplasmin (CP) is an enzyme (EC 1.16.3.1) synthesized in the liver containing 6 atoms of copper in its structure. Ceruloplasmin carries more than 95% of the total copper in healthy human plasma. The rest is accounted for by macroglobulins. Ceruloplasmin exhibits a copper-dependent oxidase activity, which is associated with possible oxidation of Fe2+ (ferrous iron) into Fe3+ (ferric iron), therefore assisting in its transport in the plasma in association with transferrin, which can carry iron only in the ferric state. The molecular weight of human ceruloplasmin is reported to be 151kDa. Mutations have been known to disrupt the binding of copper to CP and will disrupt iron metabolism and cause an iron overload. Ceruloplasmin is a relatively large enzyme (~10 nm); the larger size prevents the bound copper from being lost in a person's urine during transport.
=== Apple Inc. === Starbucks has partnered with Apple Inc. to collaborate on selling music as part of the "coffeehouse experience". In October 2006, Apple added a Starbucks Entertainment area to the iTunes Store, selling music similar to that played in Starbucks stores. In September 2007, Apple announced that customers would be able to browse the iTunes Store at Starbucks via Wi-Fi in the US—with no requirement to log into the Wi-Fi network—targeted at iPhone, iPod Touch, iPad, and MacBook users. The iTunes Store automatically detects recent songs playing in a Starbucks and offer users the opportunity to download the tracks. Some stores feature LCD screens with the artist name, song, and album information of the current song playing. This feature was rolled out in Seattle, New York City, and the San Francisco Bay Area, and was offered in limited markets during 2007–2008. During the fall of 2007, Starbucks also began to sell digital downloads of certain albums through iTunes. Starbucks gave away 37 different songs for free download through iTunes as part of the "Song of the Day" promotion in 2007, and a free "Pick of the Week" download is available from the App Store.
== Death == Farthing died on 6 April 2014 of a heart attack while travelling in a taxi in Hong Kong. His funeral was held at Church of St Michael and All Angels, an Anglican church in Christchurch on 22 April 2014. He is buried on Banks Peninsula.
== Society and culture == Benzocaine is found, particularly in Britain in the 2010s, as an additive in street cocaine and also as a bulking agent in "legal highs". Benzocaine gives a numbing effect similar to cocaine and as a bulking and binding agent it can not be detected once mixed. It is the most popular cutting agent worldwide.
November 22: DN Aidit, Chairman of Communist Party of Indonesia, is executed by the Indonesian Army in Boyolali after becoming a fugitive as a consequence of the 30 September Movement which are blamed on the Communist Party of Indonesia. December 4: The Gemini 7 completes 206 orbits around the Earth, equating to roughly one trip to the Moon.
Sources: en.wikipedia.org
A sperm bank, semen bank, or cryobank is a facility that purchases, stores, and sells human semen. The semen is produced and sold by men who are known as sperm donors. The sperm is purchased by other persons for the purpose of achieving a pregnancy other than by a sexual partner. Sperm sold by a sperm donor is known as donor sperm. A sperm bank may be a separate entity supplying donor sperm to individuals or to fertility clinics, or it may be a facility which is run by a clinic for their customers. A pregnancy may be achieved using donor sperm for insemination with similar outcomes to sexual intercourse. By using sperm from a donor rather than from the sperm recipient's partner, the process is a form of third party reproduction. In the 21st century artificial insemination with donor sperm from a sperm bank is most commonly used for individuals with no male partner, such as single women and coupled lesbians. A sperm donor must generally meet specific requirements regarding age and screening for adverse medical history. In the United States, sperm banks are regulated as Human Cell and Tissue or Cell and Tissue Bank Product (HCT/Ps) establishments by the Food and Drug Administration. Many states in the U.S. also have regulations in addition to those imposed by the FDA. In the European Union a sperm bank must have a license, according to the EU Tissue Directive. In the United Kingdom, sperm banks are regulated by the Human Fertilisation and Embryology Authority.
=== EC 2.7.2: Phosphotransferases with a carboxy group as acceptor === EC 2.7.2.1: acetate kinase EC 2.7.2.2: carbamate kinase EC 2.7.2.3: phosphoglycerate kinase EC 2.7.2.4: aspartate kinase EC 2.7.2.5: Now EC 6.3.4.16, carbamoyl-phosphate synthase (ammonia) EC 2.7.2.6: formate kinase EC 2.7.2.7: butyrate kinase EC 2.7.2.8: acetylglutamate kinase EC 2.7.2.9: Now EC 6.3.5.5, carbamoyl-phosphate synthase (glutamine-hydrolysing) EC 2.7.2.10: phosphoglycerate kinase (GTP) EC 2.7.2.11: glutamate 5-kinase EC 2.7.2.12: acetate kinase (diphosphate) EC 2.7.2.13: Now known to be due to the activities of EC 6.1.1.17, glutamate—tRNA ligase, EC 1.2.1.70, glutamyl-tRNA reductase and EC 5.4.3.8 glutamate-1-semialdehyde 2,1-aminomutase EC 2.7.2.14: branched-chain-fatty-acid kinase EC 2.7.2.15: propionate kinase EC 2.7.2.16: 2-phosphoglycerate kinase EC 2.7.2.17: [amino-group carrier protein]-L-2-aminoadipate 6-kinase EC 2.7.2.18: fatty acid kinase
In Tulsa, Jolene finds work as a receptionist and banquet server. She meets Brad Benton, the son of a wealthy family. He relentlessly pursues her, sending flowers to her workplace and charming her into dates. Outwardly religious but obnoxiously arrogant, he is rude, entitled, narcissistic and demanding to everyone. Brad pressures Jolene into quickly getting married and on their wedding night, he discovers a tattoo of a heart with flames on her backside, this triggers him and he anally rapes her. When Jolene becomes pregnant, Brad interrogates her on how many people she has had sex with; when she refuses to comply, he slaps her across the face. After their baby is born, Brad's parents investigate Jolene's past and inform him. He then brutally attacks her, permanently damaging her vocal cords. She tries to leave and take Brad Jr., but a domestic violence lawyer refuses to take her case due to her past. While staying in a shelter for battered women, the police come and arrest Jolene for kidnapping and Brad is granted an annulment. Jolene is convicted of the kidnapping and is allowed supervised visits. She decides to exit her baby's life while he is an infant, reasoning that he can imagine his mother to be anybody. Finally, Jolene ends up in Los Angeles, working as a comic illustrator for a graphic novel company, where she incorporates events from her life into her work. In her final narration, she reveals that she has dreams to be an actress and that a film studio might want to use her.
Pulmonary hypertension has been gaining recognition as a complication of chronic hereditary and acquired hemolysis. Free hemoglobin released during hemolysis inactivates the vasodilator nitric oxide (NO). Hemolysis also releases arginase that depletes L-arginine, the substrate needed for NO synthesis. This reduces NO-dependent vasodilation and induces platelet activation, thrombin generation, procoagulant factors and tissue factor activation, contributing to the formation of thrombosis. This can lead to esophageal spasm and dysphagia, abdominal pain, erectile dysfunction, systemic hypertension, decreased organ perfusion, promotion of inflammation and coagulation, and thrombosis. Chronic hemolysis may also lead to endothelial dysfunction, heightened endothelin-1-mediated responses and vasculopathy. The release of heme leads to the production of bilirubin and depletion of plasma proteins, such as albumin, haptoglobin, and hemopexin, which may lead to jaundice. It may also lead to increased levels of the heme breakdown product stercobilin in the stool. Splenectomy of those with hemolytic disorders appears to increase risk of developing pulmonary thrombosis. Complications may also arise from the increased workload for the kidney as it secretes erythropoietin to stimulate the bone marrow to produce more reticulocytes (red blood cell precursors) to compensate for the loss of red blood cells due to hemolysis.
Upon his return to the United States in 1973, he became deputy commander for operations at George Air Force Base, California. In 1974 he was assigned as vice commander at Nellis Air Force Base, Nevada, where he flew as an aggressor pilot. He then transferred to Tactical Air Command at Langley Air Force Base in 1975 as director of fighter and reconnaissance operations. In 1976 and 1977 he was assistant to the commander there. Chain became the military assistant to the Secretary of the Air Force in 1978. He then served as deputy director of plans at Air Force headquarters until 1980, when he became director of operations. Chain was assigned as assistant deputy chief of staff for plans and operations in 1981 and became deputy chief of staff for plans and operations in 1982. He served as director of the Bureau of Political-Military Affairs for the Department of State from 1984 until 1985, when he became chief of staff for Supreme Headquarters Allied Powers Europe in Belgium. On July 1, 1985, Chain was promoted to general. In 1986 he became commander in chief of Strategic Air Command, where he oversaw the LGM-118A Peacekeeper operations for the Reagan Administration. He retired from the military on January 31, 1991.
Sources: en.wikipedia.org
Angiogenesis, the formation of new blood vessels, is often critical for tumour cells to survive and grow in nutrient-depleted conditions. Akt is activated downstream of vascular endothelial growth factor (VEGF) in endothelial cells in the lining of blood vessels, promoting survival and growth. Akt also contributes to angiogenesis by activating endothelial nitric oxide synthase (eNOS), which increases production of nitric oxide (NO). This stimulates vasodilation and vascular remodelling. Signaling through the PI3K-Akt pathway increases translation of hypoxia-inducible factor α (HIF1α and HIF2α) transcription factors via mTOR. HIF promotes gene expression of VEGF and glycolytic enzymes, allowing metabolism in oxygen-depleted environments.
year is the laboratory's determination of the age of the sample, in radiocarbon years range is the laboratory's estimate of the error in the age, at 1σ confidence. 'BP' stands for "before present", referring to a reference date of 1950, so that "500 BP" means the year AD 1450. For example, the uncalibrated date "UtC-2020: 3510 ± 60 BP" indicates that the sample was tested by the Utrecht van der Graaff Laboratorium ("UtC"), where it has a sample number of "2020", and that the uncalibrated age is 3510 years before present, ± 60 years. Related forms are sometimes used: for example, "2.3 ka BP" means 2,300 radiocarbon years before present (i.e. 350 BC), and "14C yr BP" might be used to distinguish the uncalibrated date from a date derived from another dating method such as thermoluminescence. Calibrated 14C dates are frequently reported as "cal BP", "cal BC", or "cal AD", again with 'BP' referring to the year 1950 as the zero date. Radiocarbon gives two options for reporting calibrated dates. A common format is "cal date-range confidence", where:
As it is now accepted that not only transition metals, but also anions in cathodes participate in redox activity necessary for lithium insertion and removal, the design of cathode materials with diverse transition metal cations increasingly consider also oxygen redox reactions in lithium-ion battery cathodes and how these may enhance capacity beyond transition metal limitations, with computational studies using density functional theory helping to optimize materials while minimizing structural degradation. Advances in anionic redox understanding have led to stabilization strategies like surface fluorination, improving cycling stability and safety.
The Rhodesian African Rifles were based at Borrowdale in north-east Salisbury between 1940 and 1943. Apart from a contingent sent south to Durban to guard Italian prisoners on their way to Rhodesia, the regiment's main role was garrison duties within the colony. The Rhodesian Air Askari Corps, a unit of black volunteer troops under white command, guarded the air bases and also provided manpower for non-armed labour. The perceived possibility that Japan might attempt an invasion of southern Africa via Madagascar led to the consolidation of a few hundred rural whites into the Southern Rhodesia Commando, a part-time cadre intended as the basis for a guerrilla-style resistance movement, from 1942. The mobilisation of white British South Africa Police officers for military service led to black male and white female constables taking on higher responsibilities. The BSAP recruited more black patrolmen to accommodate the growth of the urban black population during the war, going from 1,067 black and 547 white personnel in 1937 to 1,572 blacks and 401 whites in 1945. This "Africanisation" led to higher appreciation for black constables among senior policemen and the public. The police remained rigidly segregated, but black constables received uniforms more similar to those of their white counterparts, and the nominal distinction between the BSAP "proper" and the British South Africa Native Police—the "force within the force" black personnel were traditionally regarded as members of—was abolished.
Sources: en.wikipedia.org
The plus sign indicates the oxidized form of nicotinamide adenine dinucleotide, which can accept electrons. When it accepts electrons, it becomes NADH. The two forms together support redox reactions in cells.
No. NAD+ is the oxidized form and NADH is the reduced form. They differ by two electrons and a proton equivalent, and cells interconvert them during metabolism.
Yes. NAD+ is present in all living cells and is required for fundamental metabolic reactions. Its concentration varies by tissue, compartment, and time.
Common methods include LC-MS, HPLC with UV detection, and enzymatic cycling assays. Rapid quenching is needed because NAD+ and NADH interconvert. The chosen method should be validated for the sample matrix.