1,6-Digalloylglucose, or more specifically 1,6-di-O-galloyl-β-D-glucose, is a gallotannin. It can be found in some oak species.[1]
References
^Mämmelä, Pirjo; Savolainen, Heikki; Lindroos, Lasse; Kangas, Juhani; Vartiainen, Terttu (2000). "Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry". Journal of Chromatography A. 891 (1): 75–83. doi:10.1016/S0021-9673(00)00624-5. PMID10999626.