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| Formula | C15H11Cl2NO3 |
| Molar mass | 324.16 g·mol−1 |
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Alda-1 is an organic compound that enhances the enzymatic activity of human ALDH2. [1] Alda-1 has been proposed as a potential treatment for the alcohol flush reaction experienced by people with genetically deficient ALDH2. [2]
Ethanol is metabolized to acetaldehyde in people, which is then metabolized to acetic acid primarily by ALDH2. [1] People have various ALDH2 alleles. ALDH2*1 is a common allele (wild type), but about 40% of people of East Asian ethnicity have one or two copies of the dominant ALDH2*2 instead, which causes ALDH2 deficiency. If deficient people drink ethanol, they suffer from alcohol flush reaction due to acetaldehyde accumulation. [3]
Four Alda-1 molecules bind to each monomer of ALDH2 tetramer. This enhances NAD+ binding to ALDH2. NAD+ is required by ALDH2 for its enzymatic activity, [4] which is why Alda-1 increases ALDH2 activity by 2.1 fold if ALDH2 is coded by ALDH2*1 and by 11 fold if it is coded ALDH2*2. [2]
Chen et al. first reported Alda-1 in 2008. [2] [1] Alda-1 is the first known aldehyde dehydrogenase activator. [3]
A dehydrogenase is an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron acceptor, usually NAD+/NADP+ or a flavin coenzyme such as FAD or FMN. Like all catalysts, they catalyze reverse as well as forward reactions, and in some cases this has physiological significance: for example, alcohol dehydrogenase catalyzes the oxidation of ethanol to acetaldehyde in animals, but in yeast it catalyzes the production of ethanol from acetaldehyde.
Acetaldehyde (IUPAC systematic name ethanal) is an organic chemical compound with the formula CH3 CHO, sometimes abbreviated as MeCHO. It is a colorless liquid or gas, boiling near room temperature. It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale in industry. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants. It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption. Pathways of exposure include air, water, land, or groundwater, as well as drink and smoke. Consumption of disulfiram inhibits acetaldehyde dehydrogenase, the enzyme responsible for the metabolism of acetaldehyde, thereby causing it to build up in the body.
Alcohol dehydrogenases (ADH) (EC 1.1.1.1) are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide (NAD+) to NADH. In humans and many other animals, they serve to break down alcohols that are otherwise toxic, and they also participate in the generation of useful aldehyde, ketone, or alcohol groups during the biosynthesis of various metabolites. In yeast, plants, and many bacteria, some alcohol dehydrogenases catalyze the opposite reaction as part of fermentation to ensure a constant supply of NAD+.
Disulfiram is a medication used to support the treatment of chronic alcoholism by producing an acute sensitivity to ethanol. Disulfiram works by inhibiting the enzyme aldehyde dehydrogenase, causing many of the effects of a hangover to be felt immediately following alcohol consumption. Disulfiram plus alcohol, even small amounts, produces flushing, throbbing in the head and neck, a throbbing headache, respiratory difficulty, nausea, copious vomiting, sweating, thirst, chest pain, palpitation, dyspnea, hyperventilation, fast heart rate, low blood pressure, fainting, marked uneasiness, weakness, vertigo, blurred vision, and confusion. In severe reactions there may be respiratory depression, cardiovascular collapse, abnormal heart rhythms, heart attack, acute congestive heart failure, unconsciousness, convulsions, and death.
Acetaldehyde dehydrogenases are dehydrogenase enzymes which catalyze the conversion of acetaldehyde into acetyl-CoA. This can be summarized as follows:
Alcoholic polyneuropathy is a neurological disorder in which peripheral nerves throughout the body malfunction simultaneously. It is defined by axonal degeneration in neurons of both the sensory and motor systems and initially occurs at the distal ends of the longest axons in the body. This nerve damage causes an individual to experience pain and motor weakness, first in the feet and hands and then progressing centrally. Alcoholic polyneuropathy is caused primarily by chronic alcoholism; however, vitamin deficiencies are also known to contribute to its development. This disease typically occurs in chronic alcoholics who have some sort of nutritional deficiency. Treatment may involve nutritional supplementation, pain management, and abstaining from alcohol.
Alcohol flush reaction is a condition in which a person develops flushes or blotches associated with erythema on the face, neck, shoulders, ears, and in some cases, the entire body after consuming alcoholic beverages. The reaction is the result of an accumulation of acetaldehyde, a metabolic byproduct of the catabolic metabolism of alcohol, and is caused by an aldehyde dehydrogenase 2 deficiency.
Alcohol tolerance refers to the bodily responses to the functional effects of ethanol in alcoholic beverages. This includes direct tolerance, speed of recovery from insobriety and resistance to the development of alcohol use disorder.
Aldehyde dehydrogenases are a group of enzymes that catalyse the oxidation of aldehydes. They convert aldehydes to carboxylic acids. The oxygen comes from a water molecule. To date, nineteen ALDH genes have been identified within the human genome. These genes participate in a wide variety of biological processes including the detoxification of exogenously and endogenously generated aldehydes.
Ethanol, an alcohol found in nature and in alcoholic drinks, is metabolized through a complex catabolic metabolic pathway. In humans, several enzymes are involved in processing ethanol first into acetaldehyde and further into acetic acid and acetyl-CoA. Once acetyl-CoA is formed, it becomes a substrate for the citric acid cycle ultimately producing cellular energy and releasing water and carbon dioxide. Due to differences in enzyme presence and availability, human adults and fetuses process ethanol through different pathways. Gene variation in these enzymes can lead to variation in catalytic efficiency between individuals. The liver is the major organ that metabolizes ethanol due to its high concentration of these enzymes.
Aldehyde dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the ALDH2 gene located on chromosome 12. ALDH2 belongs to the aldehyde dehydrogenase family of enzymes. Aldehyde dehydrogenase is the second enzyme of the major oxidative pathway of alcohol metabolism. ALDH2 has a low Km for acetaldehyde, and is localized in mitochondrial matrix. The other liver isozyme, ALDH1, localizes to the cytosol.
A hangover is the experience of various unpleasant physiological and psychological effects usually following the consumption of alcohol, such as wine, beer, and liquor. Hangovers can last for several hours or for more than 24 hours. Typical symptoms of a hangover may include headache, drowsiness, concentration problems, dry mouth, dizziness, fatigue, gastrointestinal distress, absence of hunger, light sensitivity, depression, sweating, hyper-excitability, irritability, and anxiety.
Aldehyde dehydrogenase, dimeric NADP-preferring is an enzyme that in humans is encoded by the ALDH3A1 gene.
Alcohol dehydrogenase 1A is an enzyme that in humans is encoded by the ADH1A gene.
The short-term effects of alcohol consumption range from a decrease in anxiety and motor skills and euphoria at lower doses to intoxication (drunkenness), to stupor, unconsciousness, anterograde amnesia, and central nervous system depression at higher doses. Cell membranes are highly permeable to alcohol, so once it is in the bloodstream, it can diffuse into nearly every cell in the body.
Coprine is a mycotoxin. It was first isolated from common inkcap. It occurs in mushrooms in the genera Coprinopsis. When combined with alcohol, it causes "Coprinus syndrome". It inhibits the enzyme acetaldehyde dehydrogenase, which is involved in the metabolism of alcohol. This inhibition leads to a buildup of acetaldehyde, causing an alcohol flush reaction. Because of this, the mushroom is commonly referred to as Tippler's Bane.
Pseudohypoxia refers to a condition that mimics hypoxia, by having sufficient oxygen yet impaired mitochondrial respiration due to a deficiency of necessary co-enzymes, such as NAD+ and TPP. The increased cytosolic ratio of free NADH/NAD+ in cells (more NADH than NAD+) can be caused by diabetic hyperglycemia and by excessive alcohol consumption. Low levels of TPP results from thiamine deficiency.
Alcohol-induced respiratory reactions, also termed alcohol-induced asthma and alcohol-induced respiratory symptoms, are increasingly recognized as a pathological bronchoconstriction response to the consumption of alcohol that afflicts many people with a "classical" form of asthma, the airway constriction disease evoked by the inhalation of allergens. Alcohol-induced respiratory reactions reflect the operation of different and often racially related mechanisms that differ from those of classical, allergen-induced asthma.
Alcohol intolerance is due to a genetic polymorphism of the aldehyde dehydrogenase enzyme, which is responsible for the metabolism of acetaldehyde. This polymorphism is most often reported in patients of East Asian descent. Alcohol intolerance may also be an associated side effect of certain drugs such as disulfiram, metronidazole, or nilutamide. Skin flushing and nasal congestion are the most common symptoms of intolerance after alcohol ingestion. It may also be characterized as intolerance causing hangover symptoms similar to the "disulfiram-like reaction" of aldehyde dehydrogenase deficiency or chronic fatigue syndrome. Severe pain after drinking alcohol may indicate a more serious underlying condition.
Reactive aldehyde species (RASP), also known as reactive aldehydes, refer to a class of electrophilic organic aldehyde molecules that are generally toxic or facilitate inflammation. RASP covalently react with amine groups and thiol groups, particularly in proteins. Following threshold amounts of binding to the electrophile-responsive proteome, RASP modify protein function, as has been described with MAP kinase, protein kinase C, and other proteins that potentiate cytokine release and other aspects of inflammation. Binding of RASP to proteins can also lead to NF-kB activation, autoantibody formation, inflammasome activation, and activation of Scavenger Receptor A. RASP are formed via a variety of processes, including oxidation of alcohols, polyamine metabolism and lipid peroxidation. In addition to binding to proteins and other amine or thiol-containing molecules such as glutathione, RASP are metabolized by aldehyde dehydrogenases or aldehyde reductases. Due to the toxicity of RASP, only a small number of genetic mutations in aldehyde dehydrogenases allow for viable offspring, resulting in Sjögren-Larsson Syndrome, Succinic Semi-Aldehyde Dehydrogenase Deficiency, and other rare diseases.