Bioactive Phenolics and Free Radical Scavenging Activity of Takhtajania perrieri (Winteraceae)

Background: Takhtajania perrieri is a critically endangered plant species endemic to Madagascar, belonging to the Winteraceae family. Known as a "living fossil," its rarity and protected status have limited extensive research into its traditional uses. However, its close relatives in the Winteraceae family have been traditionally used to treat ailments like scurvy and stomach issues, suggesting a potential for bioactive compounds within the species.[1] Aim of the study: This study seeks to determine the phenolic compounds and antioxidant properties of Takhtajania perrieri leaves. Materials and methods: Our team investigated the chemical composition of crude leaf extracts prepared with different solvents: ethanol, hexane, ethyl acetate, and butanol. The isolation of products was achieved through column and thin-layer chromatography. Their structures were elucidated via a combined analysis of 1D and 2D NMR spectra, with confirmation from existing scientific data. Finally, the antioxidant properties of the hexane, ethyl acetate, and butanolic fractions were evaluated using the DPPH° free radical scavenging method. Results: According to this method, crude ethanolic extract of Takhtajania perrieri leaves exhibited an antioxidant capacity (IC50= 2.58 µg / ml), the antioxidant capacity being more powerful than α-tocopherol (11.43 µg / ml), used as standard drug. Its antioxidant capacity is focalised in ethyl acetate extract (IC50= 2.19 μg/ml). The fractionation of the ethyl acetate and butanolic extracts led to the isolation of four phenolic compounds: genistéine (P1), quercetin (P2), 7-hydroxy-4'-methoxyisoflavone(P3) and luteolin (P4).