Gallotannin 1,2,6-tri-O-galloyl-β-d-glucopyranose: Its availability and changing patterns in tea (Camellia sinensis)

Gallotannin 1,2,6-tri-O-galloyl-β-d-glucopyranose (1,2,6-TGGP) plays multiple roles against multidrug-resistant bacteria and other diseases. Nevertheless, its availability in tea (Camellia sinensis) has rarely been reported. Herein, the identification and verification of 1,2,6-TGGP from Camellia sinensis using ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-qTOF MS/MS), electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) were reported. The isolated 1,2,6-TGGP was used for the chemotaxonomy analysis of 17 tea cultivars. The contents of 1,2,6-TGGP ranged from 1.96 to 43.20 mg g^-1, with a mean of 13.75 mg g^-1. Relatively high 1,2,6-TGGP contents (>30 mg g^-1) in two tea cultivars indicate that the beneficial effects of 1,2,6-TGGP can be obtained by consuming these teas. The chemotaxonomy analysis showed a biosynthetic relation between 1,2,6-TGGP and gallic acid. Further analysis showed that the 1,2,6-TGGP contents significantly decreased with the plucking times irrespective of the cultivars. Moreover, a positive and significant correlation was also observed between 1,2,6-TGGP and gallic acid. The identification of tea cultivars that are rich in 1,2,6-TGGP was first reported and the obtained results should boost their potential use in food and medicine.