Leucocyanidin
Leucocyanidin is a colorless natural compound in the flavonoid family called leucoanthocyanidins. It is a building block in the production of tannins (proanthocyanidins) in many plants and helps make other flavonoids.
In the lab, (+)-leucocyanidin can be made by reducing (+)-dihydroquercetin with sodium borohydride.
In plants, leucocyanidin can react with catechin very quickly to form procyanidins, such as B3, B6, and C2, under mildly acidic conditions.
Leucocyanidin oxygenase uses leucocyanidin, 2-oxoglutarate, and oxygen to produce cis-dihydroquercetin and trans-dihydroquercetin (taxifolin), along with succinate, carbon dioxide, and water. Leucoanthocyanidin reductase (LAR or LCR) uses catechin, NADP+, and water to make 2,3-trans-3,4-cis-leucocyanidin, generating NADPH and H+. This enzyme has been studied in grape berries and grape leaves, and its activity has been measured in leaves, flowers, and seeds of several legumes.
The 4-position stereochemistry of leucocyanidin affects the products made by anthocyanidin synthase (ANS), an iron(II) and 2-oxoglutarate–dependent oxygenase.
Leucocyanidin is found in various plants and plays a role in producing colorful flavonoids and tannins that help plants color, defend against pests, and adapt to their environment.
This page was last edited on 2 February 2026, at 12:50 (CET).