Wikipedia
Leuco-fisetinidin
Leuco-fisetinidin is a flavan-3,4-diol (leucoanthocyanidin), a type of natural phenolic substance. It is the monomer of condensed tannins called profisetinidins. Those tannins can be extracted from the heartwood of Acacia mearnsii or from the heartwoods of Schinopsis balansae, Schinopsis quebrachocolorado and from commercial quebracho extract.