Caracterização química das cascas das sementes de espécies do gênero Theobroma

Abstract

The species Theobroma grandiflorum, T. cacao and T. subincanum belong to the genus Theobroma of the family Sterculiaceae. Chemically, the species of the genus are characterized by presenting purine triterpenes, steroids, flavonoids and alkaloids. Studies conducted by the Amazon Biomolecule Chemistry Research Group (Q-BiomA) reported a chemical profile rich in phenolic compounds in the T. grandiflorum seed husks. These results motivated the execution of the present work of comparison of species of Theobroma with similar physical and chemical characteristics and evaluation of the antioxidant activity of the species. The hydroalcoholic extracts of the husks of the seeds of the three species were obtained by exhaustive maceration, the species T. grandiflorum presented higher yield. Three partition methodologies were tested and by CCDAE and MS analysis and methodology 1 was selected. The chromatographic profile was evaluated by CCDAE, where it was possible to suggest the presence of different flavonoids. Negative mode MS showed similarity of T. grandiflorum and T. subincanum species. The factions were analyzed by UHPLC-DAD in a 20min gradient mode run. It was possible to observe the presence of theacrine by comparing the data obtained with the theacrine pattern in the species T. grandiflorum and T. subincanum. The results obtained from the analyzes performed with all fractions of the species under study, by UHPLC-EMAR/MS2, allowed to identify different phenolic substances, in T. subincanum, m/z 179 (caffeic acid), m/z 191 (isocitric acid), m/z 329 (vanillic glucoside acid) m/z 431 (vitexine), m/z 477 (hypoleatin-8-O-β-D-glucuronide), m/z 557 (hypoleatin-8-O-β-D-glucuronide 3''-sulfate), m/z 461 (isoscutellareine-8-O-β-D-glucuronide), m/z 541 (teograndin I), these substances were first reported in the species. The global metabolomics was applied with PCA and HCA multivariate methods, where it was possible to confirm the similarity of all analyzed fractions, between T. grandiflorum and T. subincanum species and the differentiation of T. cacao species. The hydroalcoholic extract of T. grandiflorum was the most quantitatively active against the two free radicals, DPPH (44,50 ± 3,35 µg/mL ± DP) and ABTS (72,17 ± 0,76 µg/mL ± DP). The use of different chromatographic techniques and different detectors confirmed the similarity of the chemical profile of the seed husks of T. grandiflorum and T. subincanum species chromatographic techniques.