In organic chemistry, a cyanohydrin or hydroxynitrile is a functional group found in organic compounds in which a cyano and a hydroxy group are attached to the same carbon atom. The general formula is R2C(OH)CN, where R is H, alkyl, or aryl. Cyanohydrins are industrially important precursors to carboxylic acids and some amino acids. Cyanohydrins can be formed by the cyanohydrin reaction, which involves treating a ketone or an aldehyde with hydrogen cyanide (HCN) in the presence of excess amounts of sodium cyanide (NaCN) as a catalyst:
The enzyme (+)-δ-cadinene synthase catalyzes the chemical reaction
Linamarin is a cyanogenic glucoside found in the leaves and roots of plants such as cassava, lima beans, and flax. It is a glucoside of acetone cyanohydrin. Upon exposure to enzymes and gut flora in the human intestine, linamarin and its methylated relative lotaustralin can decompose to the toxic chemical hydrogen cyanide; hence food uses of plants that contain significant quantities of linamarin require extensive preparation and detoxification. Ingested and absorbed linamarin is rapidly excreted in the urine and the glucoside itself does not appear to be acutely toxic. Consumption of cassava products with low levels of linamarin is widespread in the low-land tropics. Ingestion of food prepared from insufficiently processed cassava roots with high linamarin levels has been associated with dietary toxicity, particularly with the upper motor neuron disease known as konzo to the African populations in which it was first described by Trolli and later through the research network initiated by Hans Rosling. However, the toxicity is believed to be induced by ingestion of acetone cyanohydrin, the breakdown product of linamarin. Dietary exposure to linamarin has also been reported as a risk factor in developing glucose intolerance and diabetes, although studies in experimental animals have been inconsistent in reproducing this effect and may indicate that the primary effect is in aggravating existing conditions rather than inducing diabetes on its own.
Lotaustralin is a cyanogenic glucoside found in small amounts in Fabaceae austral trefoil, cassava, lima bean, roseroot and white clover, among other plants. Lotaustralin is the glucoside of methyl ethyl ketone cyanohydrin and is structurally related to linamarin, the acetone cyanohydrin glucoside also found in these plants. Both lotaustralin and linamarin may be hydrolyzed by the enzyme linamarase to form glucose and a precursor to the toxic compound hydrogen cyanide.
Acetone cyanohydrin (ACH) is an organic compound used in the production of methyl methacrylate, the monomer of the transparent plastic polymethyl methacrylate (PMMA), also known as acrylic. It liberates hydrogen cyanide easily, so it is used as a source of such. For this reason, this cyanohydrin is also highly toxic.
In enzymology, a (R)-6-hydroxynicotine oxidase (EC 1.5.3.6) is an enzyme that catalyzes the chemical reaction
In enzymology, a (S)-6-hydroxynicotine oxidase (EC 1.5.3.5) is an enzyme that catalyzes the chemical reaction
The enzyme 4-hydroxy-4-methyl-2-oxoglutarate aldolase catalyzes the chemical reaction
The enzyme hydroxymandelonitrile lyase catalyzes the chemical reaction
In enzymology, a hydroxynitrilase is an enzyme that catalyzes the chemical reaction
The enzyme (R)-mandelonitrile lyase (EC 4.1.2.10, (R)-HNL, (R)-oxynitrilase, (R)-hydroxynitrile lyase) catalyzes the chemical reaction
The enzyme amorpha-4,11-diene synthase (ADS) catalyzes the chemical reaction
Pectin lyase, also known as pectolyase, is a naturally occurring pectinase, a type of enzyme that degrades pectin. It is produced commercially for the food industry from fungi and used to destroy residual fruit starch, known as pectin, in wine and cider. In plant cell culture, it is used in combination with the enzyme cellulase to generate protoplasts by degrading the plant cell walls.
The enzyme hydroxyacylglutathione hydrolase (EC 3.1.2.6, systematic name = S-(2-hydroxyacyl)glutathione hydrolase) catalyzes the following reaction:
In enzymology, a 2-isopropylmalate synthase (EC 2.3.3.13) is an enzyme that catalyzes the chemical reaction
In enzymology, an O-acetylhomoserine aminocarboxypropyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a linamarin synthase is an enzyme that catalyzes the chemical reaction
In organic chemistry, mandelonitrile is the nitrile of mandelic acid, or the cyanohydrin derivative of benzaldehyde. Small amounts of mandelonitrile occur in the pits of some fruits.
4-Hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl glucoside beta-D-glucosidase (EC 3.2.1.182, DIMBOAGlc hydrolase, DIMBOA glucosidase) is an enzyme with systematic name (2R)-4-hydroxy-7-methoxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-2-yl beta-D-glucopyranoside beta-D-glucosidase. This enzyme catalyses the following chemical reaction
(S)-hydroxynitrile lyase (EC 4.1.2.47, (S)-cyanohydrin producing hydroxynitrile lyase, (S)-oxynitrilase, (S)-HbHNL, (S)-MeHNL, hydroxynitrile lyase, oxynitrilase, HbHNL, MeHNL, (S)-selective hydroxynitrile lyase, (S)-cyanohydrin carbonyl-lyase (cyanide forming), hydroxynitrilase) is an enzyme with systematic name (S)-cyanohydrin lyase (cyanide forming). This enzyme catalyses the interconversion between cyanohydrins and the carbonyl compounds derived from the cyanohydrin with free cyanide, as in the following two chemical reactions:
