[7] Therefore, castalagin/ vescalagin and their derivatives contribute to the color and the taste of wines and spirits stored in oak barrels.

[5] Castalagin was first isolated in Fagaceae family woody species : Quercus (oak) and Castanea (chestnut) by Walter Mayer and co-workers (1967).

[8] In some chestnut species, such as Castanea sativa, heartwood could contain 63 mg of castalagin/ vescalagin per gram of dry wood.

[11] In some plants including oak and chestnut, the ellagitannins are formed from 1,2,3,4,6-pentagalloyl-glucose and further elaborated via oxidative dehydrogenation (tellimagrandin II and casuarictin formations).

After conversion of casuarictin to pedunculagin, the pyranose ring of the glucose opens and the family of compounds including casuariin, casuarinin, castalagin, and castlin, vescalagin and vescalin forms.