Phytochemical Analysis, Antioxidant and Antimicrobial Properties of Hexane, Ethyl acetate, and Methanol Leaf Extracts of Ipomoea hildebrandtii Vatke Shrub Plant

Abstract

Ipomoea hildebrandtii Vatke have been effectively used to relieve general body pains, treat wounds and cuts in the semi-arid region of Kenya. Hence the objective of this paper was to evaluate the phytochemical analysis, antioxidant and antimicrobial properties of hexane, ethyl acetate and methanol leaf extracts of Ipomoea hildebrandtii Vatke shrub plant. The profiling of the phytochemicals was carried out using the Fourier-transform infrared (FTIR) and Gas Chromatography-Mass spectroscopy (GC-MS) analyses. Antimicrobial and antioxidant activities of the methanol, hexane and ethyl acetate extracts of I. hildebrandtii were determined using disk diffusion and 2,2-diphenyl-l-picrylhydrazyl (DPPH) radical scavenging assays respectively. Preliminary phytochemical screening revealed that the leaf extracts are enriched with alkaloids, tannins, terpenoids, steroids, glycosides, flavonoids, phenols, quinones, and saponins. With GC-MS, the major compound tetratetracontane (73.14%) was identified in hexane and 9-octadecanamide, (Z)- in ethyl acetate and methanol extracts (30.99%) and (43.09%) respectively. The IR spectroscopy revealed various functional groups such as C=O, C=C, –OH and –NH. The methanol extract showed good antimicrobial activity at 1000 mg/mL against all the microorganisms tested except Escherichia coli while the hexane extract was the best antimicrobial activity against E. coli at 1000 mg/mL. The ethyl acetate extract showed the best antioxidant activity against DPPH (IC₅₀ = 48.70 ± 1.54 µg/mL) compared to the standard ascorbic acid (IC₅₀ = 21.24 ± 0.12 µg/mL). The experimental findings showed that all extracts from I. hildebrandtii leaves possess significant antimicrobial and antioxidant activities justifying its use in traditional medicine. These biological activities might be due to the presence of the presence of the identified phytochemicals in them.