Uncovering the phenolic diversity of Guabiju fruit: LC-MS/MS-based targeted metabolomics approach

The comprehensive composition of phenolic compounds (PC) from seven genotypes of guabiju were analyzed by high-performance liquid chromatography coupled to a diode array detector and mass spectrometry (HPLC-ESI-qTOF-MS/MS), and a targeted metabolomic approach was utilized to explore the PC-related similarities among the genotypes. Sixty-seven phenolic compounds were annotated and twenty-four were quantified in all genotypes of guabiju. The phenolic acids and anthocyanins were the major PC, representing more than 63% (w/w) of the total PC. Di-O-galloylquinic and tri-O-galloylquinic acids and ellagitannins were reported for the first time in guabiju. The results of hierarchical clustering and principal components analysis (PCA) suggested seven groups as suitable clusters to be formed according to phenolic composition. Eleven PC were selected as relevant for sample clustering, and six of them were highlighted as the most informative (in decreasing order of importance): epicatechin, catechin, (epi)gallocatechin gallate II, di-O-galloylquinic acid I, tri-O-galloylquinic acid and delphinidin 3-O-glucoside. To the best of our knowledge, this study contributes to the literature with the most complete phenolic profile of guabiju genotypes up to date. Moreover, guabiju susceptibility to fungal infestation related to PC composition was briefly discussed based on a parallel study using the same genotypes.