Phytochemical analysis and antioxidant activity of twigs and leaves extracts of Tertraclinis articulata (Vahl) Masters

Abstract

Abstract To research natural antioxidants, the present study aims to extract and identify new substances of natural origin through the phytochemical study and the evaluation of the antioxidant activity of extracts of twigs and leaves of Tetraclinis articulata (Vahl) Masters, harvested from the Khenifra region (Middle Atlas, Morocco). The Phytochemical screening, based on precipitation and complexation reactions, showed that the twigs and leaves of T. articulata contain flavonoids, tannins, alkaloids, mucilages, sterols and triterpenes. The extraction of the phenolic compounds was done using a Soxhlet apparatus. The assays of polyphenols, flavonoids and condensed tannins of the obtained extracts showed that the highest content of polyphenols was recorded by the ethyl acetate extract (654.69 ± 0.33mgEAG/gE). Concerning the flavonoids, the hydroethanolic extract records the highest content (20,31 ± 0,02mgEQ/gE). For the condensed tannins, the highest content was observed by the extract of the residual phase (27.72 ± 0.11mgEC/gE). Indeed, due to the analysis by HPLC/SM, we were able to identify in the E.MeOH of T. articulata seven flavonic glycosides which are Catechin, B-type (Epi) catechin dimer, gallocatechin, Myricetin-hexose, Myrcetin-rhamnose, Quercetin-3-o-Rhamnoside and kampferol-deoxyhexose. The in vitro evaluation of the antioxidant activity of T. articulata extracts was performed by DPPH and FRAP methods. The extracts of T. Articulata showed a significant antioxidant power. The lowest IC50 and EC0.5 were recorded by E. EtOH. These low concentrations (IC50 and CE0.5) obtained by DPPH and FRAP are 70 ± 0.07 µg/ml and 104.12 ± 1.02 µg/ml, respectively. This study revealed that the extracts of T. articulata are potentially important due to their richness in secondary metabolites of its antioxidant power.