Tergallic acid explained

Tergallic acids are trimers of gallic acid, often found naturally in the form of glycosides. Tergallic acid O- or C-glucosides that can be found in acorns of several Quercus (oak) species.^[1] The dehydrated tergallic acid C-glucoside and tergallic acid O-glucoside can be characterised in the acorns of Quercus macrocarpa.^[2] Dehydrated tergallic-C-glucoside (m/z 613) can be found in the cork from Quercus suber.^[3]

Tergallic acid glucosides can also be found in Terminalia chebula.^[4]

Tergallic acid dilactone can be found in Rhynchosia volubilis seeds.^[5]

The chemical formula is not the same as given by Kinjo et al.^[5] (molecule with an ether link between the ellagic and gallic acid residues) or by Cantos,^[1] Chapman^[2] and Fernandes et al.^[3] (molecule with a carbon-carbon link). Cantos, Fernandes and Chapman called the molecule with an ether link valoneic acid dilactone while Kinjo and Shuaibu et al.^[6] called the molecule with a carbon-carbon link flavogallonic acid dilactone.

Notes and References

1. Cantos . E. . Espín . J. C. . López-Bote . C. . de la Hoz . L. . Ordóñez . J. A. . Tomás-Barberán . F. A. . 10.1021/jf030216v . Phenolic Compounds and Fatty Acids from Acorns (Quercus spp.), the Main Dietary Constituent of Free-Ranged Iberian Pigs . Journal of Agricultural and Food Chemistry . 51 . 21 . 6248–6255 . 2003 . 14518951.
2. Web site: Chapman, J. M. . Nast, J. R. . Scholes, C. . Niemann, S. . Application of LC/ESI/MS and LC/EI/MS to the Characterization of Tannins and Flavonoids from the Acorns of Quercus macrocarpa . 2006 . Rockhurst University .
3. Fernandes . A. . Sousa . A. . Mateus . N. . Cabral . M. . de Freitas . V. . Analysis of Phenolic Compounds in Cork from Quercus suber L. by HPLC–DAD/ESI–MS . 10.1016/j.foodchem.2010.10.016 . Food Chemistry . 125 . 4 . 1398–1405 . 2011 .
4. http://www.mmh-mms.com/downloads/mp21terminaliachebula.pdf Terminalia chebula
5. Kinjo . J.. Nagao . T.. Tanaka . T.. Nonaka . G.. Okabe . H. . Antiproliferative Constituents in the Plant 8. Seeds of Rhynchosia volubilis . Biological & Pharmaceutical Bulletin . 2001 . 24 . 12 . 1443–1445 . 10.1248/bpb.24.1443 . 11767121 . . pdf . free. 10069/8375. free.
6. Shuaibu . M. N. . Wuyep . P. A. . Yanagi . T. . Hirayama . K. . Tanaka . T. . Kouno . I. . 10.1007/s00436-008-0879-6 . The use of microfluorometric method for activity-guided isolation of antiplasmodial compound from plant extracts . Parasitology Research . 102 . 6 . 1119–1127 . 2008 . 18214539. 19496595 .