CONSTITUINTES QUÍMICOS E POTENCIAIS ANTIOXIDANTE, ANTIDIABÉTICO E ANTITUMORAL DAS RAÍZES DE Ozoroa obovata (Anarcadiaceae)

Abstract

Ozoroa obovata, a medicinal plant of the Anacardiaceae family, is traditionally used in southern Africa for the treatment of various diseases, including stomachache, sexually transmitted diseases, fever, diarrhea, and respiratory infections. However, there are few studies on its chemical composition and biological activities. In this work, the ethanolic extract of the roots and their partitions were investigated. The present study identified by Gas Chromatography-Mass Spectrometry (GC-MS) in the n-hexane (HP) partition, for the first time, four cardanols: 3-(8Z)-8-pentadecen-1-yl-phenol, 3-(10Z)-8-heptdecen-1yl-phenol, and 3-(4Z,7Z)-4,7-heptadecadien-1-yl-phenol. In addition to these compounds, seven anacardic acids were annotated for the first time in HP using High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry (HPLC-ESI-MS/MS). Additionally, HPLC and 1H, 13C NMR analyses supported by DEPT 135, COSY, HSQC and HMQC experiments allowed the isolation and characterization of a phenolic ester and two flavonols, isolated for the first time in the genus Ozoroa: methyl gallate (I), fustin (II) and taxifolin (III), from the ethyl acetate (EAP) partition. In parallel, the antioxidant activity (using DPPH, FRAP and ORAC methodologies) exhibited an antioxidant effect, with emphasis on the ethyl acetate (EAP) partition (IC50 = 0.057 ± 0.2). The antidiabetic activity showed that the ethanolic extract of the roots (EER) (IC50 = 11.04 ± 1.10) and the partitions EAP (IC50 = 9.81 ± 0.80), n-butanol (BP) (IC50 = 11.27 ± 0.50 and AP (IC50 = 50.00 ± 0.20) presented the best results. Regarding the antitumor experiment (Glioblastoma), the EER, partitions and the isolated compounds II and III were evaluated for the first time, using the MTT assay. The IC50 values of the partitions indicated cytotoxicity and high selectivity against GAMG cancer cells, ranging from 11.62 to 19.80 μg mL–1, after 72 h of treatment. The presence of anacardic acids, along with the compounds isolated from O. obovata, highlights the importance of its chemical constituents. Furthermore, the biological activities presented reinforce the ethnobotanical relevance of this African plant.