Nutritional, phytoconstituents, and free radical scavenging potentials of Cola lepidota K. Schum. and Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill. leaves

This study was carried out to determine the essential oil components, protein qualities, fatty acid composition, and free radical scavenging potentials of leaves of Cola lepidota K. Schum. (Malvaceae) and Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill. (Irvingiaceae) using chromatographic and spectrophotometric methods. Thirty five bioactive components were isolated from C. lepidota leaves with myrcene, phytol, ephedrine, hexadecanoic acid, and 1,14-tetradecanediol as the main compounds while phytol, 2-furancarboxaldehyde, 5-(hydroxymethyl)-, 1-hexadecyne, carotene, and humulene were the predominant components of the I. gabonensis leaves. Leucine and arginine were the predominant essential amino acids, whereas glutamic acid and serine were the main nonessential amino acids in both leaves. The total amino acid (TAA) (70.92 g/100g), total non-essential amino acid (TNEAA) (45.87 g/100 g), and total acidic amino acid (TAAA) (23.01 g/100 g) of C. lepidota were high whereas I. gabonensis recorded higher Total essential amino acid (TEAA) (28.98 g/100 g), total aromatic amino acid (TArAA) (7.21 g/100 g), total branched chain amino acid (TBCAA) (14.28 g/100g), predicted protein efficiency ratios (P-PERs), and essential amino acid index (EAAI). C. lepidota contained 55.72% of unsaturated fatty acids, with predominance of linolenic and linoleic acids, while I. gabonensis produced 74.46% of saturated fatty acids, having myristic, lauric, and palmitic acid as the main compounds. All the radical scavenging potentials of both leaves were concentration dependent and produced higher DPPH, hydrogen peroxide, and ABTS radical scavenging potentials than the standards. This study has thus provided the scientific backing for the inclusion of both leaves for dietary and therapeutic purposes.