Identification of tea resources with high accumulation of 1-O-galloyl-6-O-luteoyl-α-D-glucose and comprehensive dissection of its variation.

Tea is a widely consumed beverage worldwide due to its rich secondary metabolites. Gallotanin: 1-O-galloyl-6-O-luteoyl-α-D-glucose (GLAG) has strong antioxidant activity and good resistance to a wide range of bacteria and malaria. Despite its potential, there have been few reports on GLAG in plants. In this study, we identified and validated the presence of GLAG in tea plants using UPLC-qTOF MS/MS and ESI-MS. We also identified a GLAG-rich tea variety, 'ZM2807', for the first time and observed significant variations in GLAG content across seasons and leaf positions. In addition, our analysis explored the variations and correlations of GLAG, catechin, and caffeine contents in a hybrid population (LJ43 × BHZ) consisting of 327 F1 individuals over three consecutive years. These results provided new insights into the potential applications of GLAG in food and medicine and offered a valuable reference for studying the dynamics of GLAG, catechin, and caffeine contents in adult tea plants.