A Comprehensive Liquid Chromatography Mass Spectroscopy (LCMS) and Nuclear Magnetic Resonance (1H-NMR) Metabolite Profiling of Methanolic Extract of Prosopis Africana Stem Bark

Abstract

The stem-bark of Prosopis africana commonly known as African mesquite or Iron tree, has been utilized in traditional medicine across Africa for its purported medicinal properties. This plant specie belongs to the Fabaceae family and is a native to Sub-Saharan Africa. Its bark has been traditionally used to treat various ailments, including malaria, fever, gastro-intestinal disorders and inflammatory conditions. This study provides a comprehensive profile of the methanolic crude extract obtained from the stem bark of Prosopis africana using LCMS molecular networking analysis and ¹H-NMR. A total of 47 metabolites were putatively identified in both positive and negative ion modes by the LCMS, while the ¹H-NMR spectroscopy validates the identities by providing some insights in their structures through assigning the chemical shifts that corresponds to their multiplicities. The 19 metabolites from the positive ionization were further classified as peptides, phenols, fatty acids, polyketides, steroids, lipids, amino acids, quinones, flavonoids, azaspiranes, fatty acyl glycines and acyl amino acids. On the other hand, the 28 metabolites from the negative ion mode were also categorized into different classes of metabolites which include: 6 alkaloids, 2 phenolic compounds, and four terpenoids. Other categories include: cycloalkene, polyether, triazines, anthraquinone, indole, carboxylic acid derivatives, flavonoid, glycoside and saponin. In addition, more than 26 clusters were also discovered using the MS/MS based molecular networking. The study contributes to the body of knowledge regarding the chemical constituents of Prosopis africana and provides a foundation for further research on its therapeutic applications in natural product-based medicine as metabolomics have never been used on Prosopis africana plant.