Luteic acid
Luteic acid is a natural phenol found in numerous fruits. It is a monolactonized tergalloyl group. Maximilian Nierenstein showed in 1945 that luteic acid was a molecule present in the myrobalanitannin, a tannin found in the fruit of Terminalia chebula and is an intermediary compound in the synthesis of ellagic acid. It can form from hexahydroxydiphenic acid. It is also present in the structure of the tannins alnusiin and bicornin.