Gabrielle Lavor de Queiroz¹, Beatriz Bastos Santos¹, Alessandra da Silva Correia¹, Leilane Falcão de Freitas¹, Diego Rodrigues², Anderson da Rocha Gripp², Rodrigo Lemes², Henriette Uthe³, Jörg Ziegler³, Ludger A. Wessjohann³, Maria Sandra Ramos Queiroz⁴, Maria Isabel Sampaio Dos Santos¹, Carla Monteiro Leal¹, Ivana Correa Ramos Leal¹

Introduction: The National Park of Jurubatiba Sandbank (PARNA Jurubatiba), located on the north region of the Rio de Janeiro State, encompasses the municipalities of Macaé, Carapebus, and Quissamã. This protected area harbors xeromorphic plant species distributed across different phytophysiognomies, which are exposed to high temperatures and low rainfall. Ternstroemia brasiliensis, commonly known as “pinta-noiva,” common in the phytophysiognomic formations of the PARNA Jurubatiba, as Clusia Open Shrub Formation (COSF), and Ericacea Open Shrub Formation (EOSF). Phytochemical studies of species from the genus Ternstroemia have reported the isolation of oleanane- and ursane-type triterpenes, triterpenoid saponins and O-glycosylated flavonoids. Biopharmacological investigations have demonstrated notable antioxidant activity. Therefore, the present study aims to carry out an untargeted metabolomic analysis of Ternstroemia brasiliensis extracts obtained from different phytophysiognomies, and to evaluate their antioxidant potential. Methods: Leaves of T. brasiliensis (n= 14; COSF and EOSF) were collected in the summer (-S) and autumn (-A) seasons and stored at -80ºC. The dry and crushed material was extracted with 1 mL MeOH:H₂O (8:2). The analyses were performed in an Agilient 1290 infinity II HPLC system coupled to a timsTOFBruker® with ESI source, in the positive ionization mode. Data processing was performed in MetaboScape®, and the data analysis in the Sirius 5.8, Metlgel, GNPS2, and Metaboanalyst 6.0. The extracts were subjected to the DPPH antioxidant assay in order to evaluate their capacity to capture and neutralize the 1,1-diphenyl-2-picrylhydrazyl radical, using rutin as standard. The assays were performed in triplicate. Results: O- and C-glycosyde flavonoids were annotated in T. brasiliensis at COSF and EOSF, in both seasons. The C-glycosyde flavonoids have not yet been reported in the literature for this species. The chemical classification by Metlgel software showed the flavonoids and terpenoids as main compounds in these extracts. An unsupervised principal component analysis (PCA) enabled the assessment and grouping of samples based on the variance in their chemical profiles. This analysis showed a clustering of samples into four distinct groups. The resulting two-component model explained 45% of the total variance. The PC1 axis showed the separation of the COSF and EOSF groups, indicating that there are chemical differences between these groups. The preliminary evaluation of antioxidant potential using the DPPH method showed promising results for autumn extracts from distinct phytophysiognomies. Among the extracts of T. brasiliensis, specimens collected at COSF-A and EOSF-A showed EC₅₀ values ​​at 2.46 ug/mL and 20.67 ug/mL, respectively, compared to 1.53ug/mL and 1.94ug/mL for rutin. Conclusions: Through this study it was possible to detect mainly flavonoids and terpenoids compounds, and antioxidant potential of the T. brasiliensis. As future perspectives, compound annotation from different phytophysiognomies formations will be continued. Furthermore, the antioxidant activity will be evaluated through the ABTS⁺ radical assay, as well as the investigation of the anti-aging potential through enzymatic inhibition of tyrosinase and elastase. In addition, the mass spectrometry data will be correlated with antioxidant and anti-aging results to investigate the possible compounds responsible for these activities.

Agradecimentos: Faperj, CNPq and CAPES for financial support. CAPES for scholarship. Leibniz Institute of Plant Biochemistry (Germany), for scientific support in the development of the research.