Leucocyanidin is a colorless chemical compound that is a member of the class of

natural products A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical sy ...

known as

leucoanthocyanidin Leucoanthocyanidin (flavan-3,4-diols) are colorless chemical compounds related to anthocyanidins and anthocyanins. Leucoanthocyanins can be found in '' Anadenanthera peregrina'' and in several species of '' Nepenthes'' including '' N. burbidg ...

Chemistry

(+)-Leucocyanidin can be synthesized from (+)-

dihydroquercetin Taxifolin (5,7,3',4'-flavan-on-ol), also known as dihydroquercetin, belongs to the subclass flavanonols in the flavonoids, which in turn is a class of polyphenols. Stereocenters Taxifolin has two stereocenters on the C-ring, as opposed to quer ...

by reduction with

sodium borohydride Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula Na BH4. This white solid, usually encountered as an aqueous basic solution, is a reducing agent that finds applica ...

. Molar equivalents of synthetic (2R,3S,4R or S)-leucocyanidin and (+)-

catechin Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tanni ...

condense with exceptional rapidity at pH 5 under ambient conditions to give the all-''trans''- ,8 and ,6bi- +)-catechins( procyanidins B3, B6) the all-''trans''- ,8:4,8 and ,8:4,6tri- +)-catechins(

procyanidin C2 Procyanidin C2 is a B type proanthocyanidin trimer, a type of condensed tannin. Natural occurrences Procyanidin C2 is found in grape seeds (''Vitis vinifera'') and wine, in barley (''Hordeum vulgare''), malt and beer, in '' Betula spp.'', in '' ...

and isomer).

Metabolism

Leucocyanidin oxygenase In enzymology, a leucocyanidin oxygenase () is an enzyme that catalyzes the chemical reaction :leucocyanidin + 2-oxoglutarate + O2 \rightleftharpoons cis- and trans-dihydroquercetins + succinate + CO2 + 2 H2O The 3 substrates of this enzyme are ...

uses leucocyanidin, 2-oxoglutarate, and O₂ to produce ''cis''-dihydroquercetin, ''trans''-

(taxifolin), succinate, CO₂, and H₂O. Leucoanthocyanidin reductase (LAR or leucocyanidin reductase LCR) uses (2''R'',3''S'')-

, NADP⁺, and H₂O to produce 2,3-''trans''-3,4-cis-leucocyanidin, NADPH, and H⁺. Its gene expression has been studied in developing grape berries and grapevine leaves. Its activity has also been measured in leaves, flowers, and seeds of the legumes ''

Medicago sativa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as w ...

'', '' Lotus japonicus'', ''

Lotus uliginosus ''Lotus pedunculatus'' (formerly ''Lotus uliginosus''), the big trefoil, greater bird's-foot-trefoil or marsh bird's-foot trefoil, is a member of the pea family (Fabaceae). It is a herbaceous perennial growing throughout Europe in damp, open loc ...

'', ''

Hedysarum sulfurescens ''Hedysarum sulphurescens'', the yellow sweetvetch or white sweetvetch, is a perennial herb species. Leucocyanidin reductase (LCR) uses 2,3-trans-3,4-cis-leucocyanidin to produce (+)-catechin and is the first enzyme in the proanthocyanidins P ...

'', and ''

Robinia pseudoacacia ''Robinia pseudoacacia'', commonly known in its native territory as black locust, is a medium-sized hardwood deciduous tree, belonging to the tribe Robinieae of the legume family Fabaceae. It is endemic to a few small areas of the United States, ...

''. The C-4 stereochemistry of leucocyanidin substrates affects anthocyanidin synthase (ANS) products. This enzyme is an iron(II) and 2-oxoglutarate (2OG) dependent oxygenase.

Occurrence

Leucoyanidin can be found in '' Aesculus hippocastanum'' (Horse chestnut), ''

Anacardium occidentale The cashew tree (''Anacardium occidentale'') is a tropical evergreen tree native to South America in the genus '' Anacardium'' that produces the cashew seed and the cashew apple accessory fruit. The tree can grow as tall as , but the dwarf cu ...

'' (Cashew, acajou), ''

Arachis hypogaea The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible seeds. It is widely grown in the tropics and subtropics, important to both small and la ...

'' (peanut), ''

Areca catechu ''Areca catechu'' is a species of palm which grows in much of the tropical Pacific, Asia, and parts of east Africa. The palm is believed to have originated in the Philippines, but is widespread in cultivation and is considered naturalized in so ...

'' (Areca nut), '' Asimina triloba'' (American custardapple), '' Cerasus vulgaris'' (Cherry), '' Cinnamomum camphora'' (Camphor), ''

Erythroxylon coca Coca is any of the four cultivated plants in the family Erythroxylaceae, native to western South America. Coca is known worldwide for its psychoactive alkaloid, cocaine. The plant is grown as a cash crop in the Argentine Northwest, Bolivia, Al ...

'' (coca), ''

Gleditsia triacanthos The honey locust (''Gleditsia triacanthos''), also known as the thorny locust or thorny honeylocust, is a deciduous tree in the family Fabaceae, native to central North America where it is mostly found in the moist soil of river valleys. Honey ...

'' (Honey locust), ''

Hamamelis virginiana ''Hamamelis virginiana'', known as witch-hazel, common witch-hazel, and American witch-hazel, is a species of flowering shrub native to eastern North America, from Nova Scotia west to Minnesota, and south to central Florida to eastern Texas. Des ...

'' (American Witch Hazel), ''

Hippophae rhamnoides ''Hippophae rhamnoides'', also known as sea-buckthorn, is a species of flowering plant in the family Elaeagnaceae, native to the cold-temperate regions of Europe and Asia. It is a spiny deciduous shrub. The plant is used in the food and cosmetic ...

'' (Hippophae berry Sanddorn), ''

Hordeum vulgare Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley pro ...

'' (Barley), ''

Humulus lupulus ''Humulus lupulus'', the common hop or hops, is a species of flowering plant in the hemp family Cannabinaceae, native to Europe, western Asia and North America. It is a perennial, herbaceous climbing plant which sends up new shoots in early s ...

'' (bine), ''

Hypericum perforatum ''Hypericum perforatum'', known as St. John's wort, is a flowering plant in the family Hypericaceae and the type species of the genus '' Hypericum''. Possibly a hybrid between '' H. maculatum'' and '' H. attenuatum'', the species can be found ...

'' (perikon Amber), ''

Laurus nobilis ''Laurus nobilis'' is an aromatic evergreen tree or large shrub with green, glabrous (smooth) leaves. It is in the flowering plant family Lauraceae. It is native to the Mediterranean region and is used as bay leaf for seasoning in cooking. ...

'', ''

Magnolia denudata ''Magnolia denudata'', the lilytree or Yulan magnolia (), is native to central and eastern China. It has been cultivated in Chinese Buddhist temple gardens since 600 AD. Its flowers were regarded as a symbol of purity in the Tang Dynasty and it ...

'' (Hsin-I Yulan-Magnolie), ''

Malva sylvestris ''Malva sylvestris'' is a species of the mallow genus '' Malva'' in the family of Malvaceae and is considered to be the type species for the genus. Known as common mallow to English-speaking Europeans, it acquired the common names of cheeses, h ...

'' (Blue mallow), '' Musa acuminata × balbisiana'' (Banana), ''

Nelumbo nucifera ''Nelumbo nucifera'', also known as sacred lotus, Laxmi lotus, Indian lotus, or simply lotus, is one of two extant taxon, extant species of aquatic plant in the Family (Biology), family Nelumbonaceae. It is sometimes colloquially called a water ...

'' (Baladi bean), '' Pinus strobus'' (Eastern white pine), ''

Prunus serotina ''Prunus serotina'', commonly called black cherry,World Economic Plants: A Standard Reference, Second Edition'. CRC Press; 19 April 2016. . p. 833–. wild black cherry, rum cherry, or mountain black cherry, is a deciduous tree or shrub of the g ...

'' ssp. serotina (black cherry), ''

Psidium guajava ''Psidium guajava'', the common guava, yellow guava, lemon guava, or apple guava is an evergreen shrub or small tree native to the Caribbean, Central America and South America. It is easily pollinated by insects; when cultivated, it is polli ...

'' (Common guava), ''

Quercus alba An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ...

'' (White oak), ''

Quercus robur ''Quercus robur'', commonly known as common oak, pedunculate oak, European oak or English oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native to most of Europe west of the Caucasus. It is widel ...

'' (Common oak), '' Rumex hymenosepalus'' (Arizona dock), '' Schinus terebinthifolius'' (Brazilian pepper tree), ''

Terminalia arjuna ''Terminalia arjuna'' is a tree of the genus '' Terminalia''. It is commonly known as arjuna or arjun tree in English. Description ''T. arjuna'' grows to about 20–25 metres tall; usually has a buttressed trunk, and forms a wide canopy at t ...

'' (arjun), ''

Terminalia catappa ''Terminalia catappa'' is a large tropical tree in the leadwood tree family, Combretaceae, native to Asia, Australia, the Pacific, Madagascar and Seychelles. Common names in English include country almond, Indian almond, Malabar almond, sea almon ...

'' (Indian almond), ''

Theobroma cacao ''Theobroma cacao'', also called the cacao tree and the cocoa tree, is a small ( tall) evergreen tree in the family Malvaceae. Its seeds, cocoa beans, are used to make chocolate liquor, cocoa solids, cocoa butter and chocolate. The largest pr ...

'' (Cacao), ''

Drimia maritima ''Drimia maritima'' ( syn. ''Urginea maritima'') is a species of flowering plant in the family Asparagaceae, subfamily Scilloideae (formerly the family Hyacinthaceae). This species is known by several common names, including squill, sea squill, ...

'' (Sea Squill), ''

Vicia faba ''Vicia faba'', commonly known as the broad bean, fava bean, or faba bean, is a species of vetch, a flowering plant in the pea and bean family Fabaceae. It is widely cultivated as a crop for human consumption, and also as a cover crop. Varieti ...

'' (bell-bean), ''

Vitis vinifera ''Vitis vinifera'', the common grape vine, is a species of flowering plant, native to the Mediterranean region, Central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran. There are curr ...

'' (common grape vine), '' Zea mays'' (corn, maize), and ''

Ziziphus jujuba Jujube (), sometimes jujuba, known by the scientific name ''Ziziphus jujuba'' and also called red date, Chinese date, and Chinese jujube, is a species in the genus '' Ziziphus'' in the buckthorn family Rhamnaceae. Description It is a sma ...

'' (jujube, Chinese date).

References

{{Leucoanthocyanidin Leucoanthocyanidins Catechols Resorcinols