Phytochemical Analysis and Antioxidant Activities of Prunus africana Bark, Leea indica and Paullinia pinnata Leaf Extracts

The phytochemical profile and antioxidant activities of <i>Prunus africana</i> bark, <i>Leea indica</i> and <i>Paullinia pinnata</i> leaves from Cameroon were investigated in this study. The yields of pure methanolic extraction were 11.9%, 11.1% and 10.8% in <i>P. africana</i> bark, <i>L. indica</i> and <i>P. pinnata</i> leaves, respectively. The total phenolic content was 189.0 ± 16.93, 163.6 ± 14.73 and 114.6 ± 10.38 mg GAE/g and total flavonoid content was 43.25 ± 6.43, 28.31 ± 4.44, and 19.75 ± 4.03 mg RU/g in <i>P. africana</i> bark, <i>L. indica</i> and <i>P. pinnata</i> leaves, respectively. The antioxidant activities of the plants were evaluated by DPPH, ABTS and FRAP assays. The IC₅₀ evaluated in <i>P. africana</i> bark, <i>L. indica</i> and <i>P. pinnata</i> leaves was 109.5 ± 13.2, 132.1 ± 18.7 and 156.1 ± 21.9 µg/mL for DPPH and 98.1 ± 4.8, 101.3 ± 12.1 and 133.9 ± 16.0 µg /mL for ABTS assay. The FRAP value was 61.1 ± 1.5, 50.5 ± 1.5 and 43.4 ± 2.1 µMFe²⁺/g in the same sequence. The functional groups for the corresponding phytochemicals, including alkane, alkene, aliphatic ether, ester, amine, α, β-unsaturated ester, alcohol, phenol, carboxylic acid, and aliphatic ketone, were identified through fourier-transform infrared analysis. The identified and quantified phenolic acids in this study were methyl-4-hydroxybenzoic, caffeic, protocatechuic and p-coumaric acid, identified using high-performance liquid chromatography.