Names | |
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Preferred IUPAC name 1-(4-Hydroxy-3-methoxyphenyl)ethan-1-one | |
Other names 1-(4-Hydroxy-3-methoxyphenyl)ethanone 4-Hydroxy-3-methoxyacetophenone Acetovanillone | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.007.141 |
KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C9H10O3 | |
Molar mass | 166.17 g/mol |
Melting point | 115 °C (239 °F; 388 K) |
Boiling point | 295–300 °C (563–572 °F; 568–573 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Apocynin, also known as acetovanillone, is a natural organic compound structurally related to vanillin. It has been isolated from a variety of plant sources and is being studied for its variety of pharmacological properties.
Apocynin was first described by Oswald Schmiedeberg, a German pharmacologist, in 1883 and was first isolated by Horace Finnemore, [1] in 1908, from the root of Canadian hemp ( Apocynum cannabinum ). [2] At the time, this plant was already used for its known effectiveness against edema and heart problems. In 1971, apocynin was also isolated from Picrorhiza kurroa, a small plant that grows at high altitudes in the western Himalayas. P. kurroa was used for ages as a treatment for liver and heart problems, jaundice, and asthma. In 1990, Simons et al. isolated apocynin to a pharmacologically useful level using an actively guided isolation procedure. Apocynin's observed anti-inflammatory capabilities proved to be a result of its ability to selectively prevent the formation of free radicals, oxygen ions, and peroxides in the body. Apocynin has since been extensively studied to help determine its disease-fighting capabilities and applications.[ citation needed ]
Apocynin is a solid with a melting point of 115 °C and the faint odor of vanilla. [3] It is soluble in hot water, [4] alcohol, benzene, chloroform, DMSO and DMF. [5]
NADPH oxidase is an enzyme that effectively reduces O2 to superoxide (O2–•), which can be used by the immune system to kill bacteria and fungi. Apocynin is an inhibitor of NADPH oxidase activity and thus is effective in preventing the production of the superoxide in human agranulocytes or neutrophilic granulocytes. It does not however obstruct the phagocytic or other defense roles of granulocytes. Due to the selectivity of its inhibition, apocynin can be widely used as an inhibitor of NADPH oxidase without interfering in other aspects of the immune system. [6] [7]
Apocynin was used to determine whether ionic activation due to proton flux across the membrane of renal medulla cells was coupled to NADPH oxidase production of superoxide. Apocynin was introduced to the cells and completely blocked the production of superoxide, and was a key component in determining that the proton outflow was responsible for the activation of NADPH oxidase. [8]
The mechanism of action of apocynin is not understood. In the experimental studies, apocynin is shown to dimerize and form diapocynin. [9] Although, diapocynin seems to have beneficial effect in reducing reactive oxygen species and anti-inflammatory properties, it is still yet to be shown as biologically relevant molecule. [10] Biotransformation of apocynin predominantly leads to glycosylated form of apocynin. Another molecule that is shown to form under experimental conditions is nitroapocynin. [11]
This section needs more reliable medical references for verification or relies too heavily on primary sources .(January 2017) |
Small scale early stage clinical trials for apocynin were conducted for chronic obstructive pulmonary disease (COPD) in 2011 [12] and asthma in 2012 [13] but they did not progress any further.
Other preliminary pre-clinical research includes:
Superoxide dismutase (SOD, EC 1.15.1.1) is an enzyme that alternately catalyzes the dismutation (or partitioning) of the superoxide (O−
2) anion radical into normal molecular oxygen (O2) and hydrogen peroxide (H
2O
2). Superoxide is produced as a by-product of oxygen metabolism and, if not regulated, causes many types of cell damage. Hydrogen peroxide is also damaging and is degraded by other enzymes such as catalase. Thus, SOD is an important antioxidant defense in nearly all living cells exposed to oxygen. One exception is Lactobacillus plantarum and related lactobacilli, which use intracellular manganese to prevent damage from reactive O−
2.
Inflammation is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function.
Xanthine oxidase is a form of xanthine oxidoreductase, a type of enzyme that generates reactive oxygen species. These enzymes catalyze the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid. These enzymes play an important role in the catabolism of purines in some species, including humans.
Neutrophils are a type of white blood cell. More specifically, they form the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying in different animals.
Chronic granulomatous disease (CGD), also known as Bridges–Good syndrome, chronic granulomatous disorder, and Quie syndrome, is a diverse group of hereditary diseases in which certain cells of the immune system have difficulty forming the reactive oxygen compounds used to kill certain ingested pathogens. This leads to the formation of granulomas in many organs. CGD affects about 1 in 200,000 people in the United States, with about 20 new cases diagnosed each year.
In chemistry and biology, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (O2), water, and hydrogen peroxide. Some prominent ROS are hydroperoxide (O2H), superoxide (O2-), hydroxyl radical (OH.), and singlet oxygen. ROS are pervasive because they are readily produced from O2, which is abundant. ROS are important in many ways, both beneficial and otherwise. ROS function as signals, that turn on and off biological functions. They are intermediates in the redox behavior of O2, which is central to fuel cells. ROS are central to the photodegradation of organic pollutants in the atmosphere. Most often however, ROS are discussed in a biological context, ranging from their effects on aging and their role in causing dangerous genetic mutations.
Myeloperoxidase deficiency is a disorder featuring lack in either the quantity or the function of myeloperoxidase–an iron-containing protein expressed primarily in neutrophil granules. There are two types of myeloperoxidase deficiency: primary/inherited and secondary/acquired. Lack of functional myeloperoxidase leads to less efficient killing of intracellular pathogens, particularly Candida albicans, as well as less efficient production and release of neutrophil extracellular traps (NETs) from the neutrophils to trap and kill extracellular pathogens. Despite these characteristics, more than 95% of individuals with myeloperoxidase deficiency experience no symptoms in their lifetime. For those who do experience symptoms, the most common symptom is frequent infections by Candida albicans. Individuals with myeloperoxidase deficiency also experience higher rates of chronic inflammatory conditions. Myeloperoxidase deficiency is diagnosed using flow cytometry or cytochemical stains. There is no treatment for myeloperoxidase deficiency itself. Rather, in the rare cases that individuals experience symptoms, these infections should be treated.
Respiratory burst is the rapid release of the reactive oxygen species (ROS), superoxide anion and hydrogen peroxide, from different cell types.
NADPH oxidase is a membrane-bound enzyme complex that faces the extracellular space. It can be found in the plasma membrane as well as in the membranes of phagosomes used by neutrophil white blood cells to engulf microorganisms. Human isoforms of the catalytic component of the complex include NOX1, NOX2, NOX3, NOX4, NOX5, DUOX1, and DUOX2.
NADPH oxidase 2 (Nox2), also known as cytochrome b(558) subunit beta or Cytochrome b-245 heavy chain, is a protein that in humans is encoded by the NOX2 gene. The protein is a superoxide generating enzyme which forms reactive oxygen species (ROS).
Anthony Segal FRS FMedSci is a British physician/scientist.
Voltage-gated proton channels are ion channels that have the unique property of opening with depolarization, but in a strongly pH-sensitive manner. The result is that these channels open only when the electrochemical gradient is outward, such that their opening will only allow protons to leave cells. Their function thus appears to be acid extrusion from cells.
Superoxide dismutase [Cu-Zn] also known as superoxide dismutase 1 or hSod1 is an enzyme that in humans is encoded by the SOD1 gene, located on chromosome 21. SOD1 is one of three human superoxide dismutases. It is implicated in apoptosis, familial amyotrophic lateral sclerosis and Parkinson's disease.
NADPH oxidase 1 is an enzyme that in humans is encoded by the NOX1 gene.
NADPH oxidase 4 is an enzyme that in humans is encoded by the NOX4 gene, and is a member of the NOX family of NADPH oxidases.
NADPH oxidase, EF-hand calcium binding domain 5, also known as NOX5, is a protein which in humans is encoded by the NOX5 gene.
NADPH oxidase 3 is an enzyme that in humans is encoded by the NOX3 gene.
Pyocyanin (PCN−) is one of the many toxic compounds produced and secreted by the Gram negative bacterium Pseudomonas aeruginosa. Pyocyanin is a blue secondary metabolite, turning red below pH 4.9, with the ability to oxidise and reduce other molecules and therefore kill microbes competing against P. aeruginosa as well as mammalian cells of the lungs which P. aeruginosa has infected during cystic fibrosis. Since pyocyanin is a zwitterion at blood pH, it is easily able to cross the cell membrane. There are three different states in which pyocyanin can exist: oxidized (blue), monovalently reduced (colourless) or divalently reduced (red). Mitochondria play an important role in the cycling of pyocyanin between its redox states. Due to its redox-active properties, pyocyanin generates reactive oxygen species.
Piclamilast, is a selective PDE4 inhibitor. It is comparable to other PDE4 inhibitors for its anti-inflammatory effects. It has been investigated for its applications to the treatment of conditions such as chronic obstructive pulmonary disease, bronchopulmonary dysplasia and asthma. It is a second generation compound that exhibits structural functionalities of the PDE4 inhibitors cilomilast and roflumilast. The structure for piclamilast was first elucidated in a 1995 European patent application. The earliest mention of the name "piclamilast" was used in a 1997 publication.
Diapocynin is a dimer of apocynin.