PHYTOCHEMICAL PROFILING, TOTAL PHENOLIC AND FLAVONOID CONTENTS, AND ANTIOXIDANT ACTIVITY OF ETHANOLIC EXTRACTS FROM FIVE SUDANESE MEDICINAL FRUITS

Background: In the Republic of Sudan, approximately 90% of the populace relies upon indigenous medicinal flora as their principal source of primary health care. Nevertheless, comprehensive scientific documentation regarding the chemical composition and pharmacological attributes of numerous locally consumed fruit species remains conspicuously deficient. Objective: The present investigation was undertaken to systematically evaluate the phytochemical constitution, quantify total phenolic and flavonoid pools, and assess the free radical‑neutralizing capacity of ethanolic extracts derived from five traditionally utilized Sudanese fruits: Ceratonia siliqua (carob), Grewia tenax (guddaim), Adansonia digitata (baobab), Hibiscus sabdariffa (roselle), and Tamarindus indica (tamarind). Methods: Desiccated plant materials underwent exhaustive maceration with 80% ethanol. Preliminary phytochemical reconnaissance was executed employing established qualitative assay protocols. Total phenolic content (TPC) and total flavonoid content (TFC) were spectrophotometrically quantified. Antioxidant efficacy was appraised via the DPPH (2,2‑diphenyl‑1‑picrylhydrazyl) radical scavenging assay, while bioactive constituent profiling was accomplished through Gas Chromatography‑Mass Spectrometry (GC‑MS). Results: T. indica yielded the highest extraction recovery (71.0%), followed by H. sabdariffa (47.28%). Phytochemical screening confirmed the ubiquitous presence of flavonoids, tannins, terpenoids, coumarins, and saponins across most specimens. C. siliqua demonstrated the most elevated TPC (1149.37 µg GAE/g dry extract) and TFC (561.36 µg CAE/g dry extract). DPPH radical scavenging activity was maximal for C. siliqua (80.0% RSA), closely trailed by H. sabdariffa (78.0% RSA) and A. digitata (76.0% RSA). GC‑MS chromatographic analysis unveiled signature bioactive markers, prominently alpha‑methyl mannofuranoside (51.26%) in C. siliqua, 5‑hydroxymethylfurfural (30.39%) in T. indica, and sucrose (19.15%) in G. tenax. Conclusion: These empirical findings substantiate that the examined Sudanese fruits constitute substantial repositories of phenolic bioactives and manifest considerable antioxidant prowess, thereby providing scientific corroboration for their ethnomedicinal utilization as functional food matrices and nutraceutical formulations.

• Maroyi, A. (2013). Traditional use of medicinal plants in south‑central Zimbabwe: Review and perspectives. Journal of Ethnobiology and Ethnomedicine, 9(1): 1‑14.
• Khalid, H. E., Abdalla, W. E., & Abdelgadir, H. A. (2012). Medicinal plants of Sudan. In Medicinal and Aromatic Plants of the World (Vol. 1, pp. 273‑296). Springer.
• Elegami, A. A., Almagboul, A. Z., Omer, M. E. A., & El Tohami, M. S. (2002). Sudanese plants used in folkloric medicine: Screening for antibacterial activity. Fitoterapia, 73(6): 531‑534.
• Gebauer, J., Patzelt, A., Hammer, K., & Buerkert, A. (2007). First record of Grewia tenax (Forssk.) Fiori in northern Oman, a valuable fruit producing shrub. Genetic Resources and Crop Evolution, 54(5): 1153‑1158.
• Elhassan, G. M., & Yagi, S. M. (2010). Nutritional composition of Grewia species (Grewia tenax (Forsk.) Fiori, G. flavescens Juss and G. villosa Willd) fruits. Advances in Journal of Food Science and Technology, 2(3): 159‑162.
• Cowan, M. M. (1999). Plant products as antimicrobial agents. Clinical Microbiology Reviews, 12(4): 564‑582.
• Braca, A., Sinisgalli, C., De Leo, M., Muscatello, B., Cioni, P. L., Milella, L., Ostuni, A., Giani, S., & Sanogo, R. (2018). Phytochemical profile, antioxidant and antidiabetic activities of Adansonia digitata L. (baobab) from Mali, as a source of health‑promoting compounds. Molecules, 23(12): 3104.
• Zhou, H. Y., & Liu, C. Z. (2006). Microwave‑assisted extraction of solanesol from tobacco leaves. Journal of Chromatography A, 1129(1): 135‑139.
• Sukhdev, S. H., Suman, P. S. K., Gennaro, L., & Dev, D. R. (2008). Extraction technologies for medicinal and aromatic plants. United Nations Industrial Development Organization (UNIDO).
• Sofowora, A. (1993). Medicinal plants and traditional medicine in Africa (2nd ed.). Spectrum Books.
• Harborne, J. B. (1984). Phytochemical methods: A guide to modern techniques of plant analysis (2nd ed.). Chapman and Hall.
• Ainsworth, E. A., & Gillespie, K. M. (2007). Estimation of total phenolic content and other oxidation substrates in plant tissues using Folin‑Ciocalteu reagent. Nature Protocols, 2(4): 875‑877.
• Singh, A., Sharma, P. K., & Garg, G. (2014). Phytochemical screening and antioxidant activity of Moringa oleifera leaves. International Journal of Pharmacy and Pharmaceutical Sciences, 6(5): 143‑147.
• Shimada, K., Fujikawa, K., Yahara, K., & Nakamura, T. (1992). Antioxidative properties of xanthan on the autoxidation of soybean oil in cyclodextrin emulsion. Journal of Agricultural and Food Chemistry, 40(6): 945‑948.
• El‑Siddig, K., Gunasena, H. P. M., Prasa, B. A., Pushpakumara, D. K. N. G., Ramana, K. V. R., Vijayanand, P., & Williams, J. T. (2006). Tamarind — Tamarindus indica L. (Fruits for the Future 1). Southampton Centre for Underutilized Crops.
• Sudjaroen, Y., Haubner, R., Würtele, G., Hull, W. E., Erben, G., Spiegelhalder, B., ... & Bartsch, H. (2005). Isolation and structure elucidation of phenolic antioxidants from Tamarind (Tamarindus indica L.) seeds and pericarp. Food and Chemical Toxicology, 43(11): 1673‑1682.
• Kyriacou, M. C., Antoniou, C., Rouphael, Y., Graziani, G., & Kyratzis, A. (2021). Mapping the primary and secondary metabolomes of carob (Ceratonia siliqua L.) fruit and its postharvest antioxidant potential at critical stages of ripening. Antioxidants, 10(1): 57.
• Ndiaye, E. M. Y. E. I., Yousra, S., Alioune, S., et al. (2021). Secondary metabolites and antioxidant activities of different parts of baobab fruit (Adansonia digitata L.). Food and Nutrition Sciences, 12(7): 732‑741.
• Güçlü‑Üstündağ, Ö., & Mazza, G. (2007). Saponins: Properties, applications and processing. Critical Reviews in Food Science and Nutrition, 47(3): 231‑258.
• Puro, K., Sunjukta, R., Samir, S., Ghatak, S., Shakuntala, I., & Sen, A. (2014). Medicinal uses of Roselle plant (Hibiscus sabdariffa L.): A mini review. Indian Journal of Hill Farming, 27(1): 81‑90.
• Fullerton, M., Khatiwadu, J., Johnson, J. U., David, S., & William, L. L. (2011). Determination of antimicrobial activity of sorrel (Hibiscus sabdariffa) on E. coli O157:H7 isolated from food, veterinary and clinical samples. Journal of Medicinal Food, 14(9): 950‑956.
• Macho‑Gonzalez, A., Garcimartin, A., Lopez‑Oliva, M. E., Bastida, S., Benedi, J., & Sanchez‑Muniz, F. J. (2017). Carob (Ceratonia siliqua L.) fruit extract as a source of phenolic compounds with antioxidant and antiproliferative activities. Food & Function, 8(4): 1589‑1597.
• Bhadoriya, S. S., Ganeshpurkar, A., Narwaria, J., Rai, G., & Jain, A. P. (2011). Tamarindus indica: A review of traditional uses, phytochemistry and pharmacology. Pharmacognosy Reviews, 5(10): 171‑181.
• Ismail, B. B., Pu, Y., Guo, M., & Liu, D. (2024). Green extraction and partial purification of roselle (Hibiscus sabdariffa L.) extracts with high amounts of phytochemicals and in vitro antioxidant and antibacterial effects. Journal of Food Science, 89(12): 8819‑8835.
• Tembo, D. T., Holmes, M. J., & Marshall, L. J. (2017). Effect of thermal treatment and storage on bioactive compounds, organic acids and antioxidant activity of baobab fruit (Adansonia digitata) pulp from Malawi. Journal of Food Composition and Analysis, 58: 40‑51.
• Papagiannopoulos, M., Wollseifen, H. R., Mellenthin, A., Haber, B., & Galensa, R. (2004). Identification and quantification of polyphenols in carob fruits (Ceratonia siliqua L.) and derived products by HPLC‑UV‑ESI/MSN. Journal of Agricultural and Food Chemistry, 52(12): 3784‑3791.
• Bruneton, J. (1999). Pharmacognosie, phytochimie, plantes médicinales (3rd ed.). Technique et Documentation Lavoisier.
• Zhao, L., Chen, J., Su, J., Li, L., Hu, S., Li, B., ... & Liu, H. (2013). In vitro antioxidant and antiproliferative activities of 5‑hydroxymethylfurfural. Journal of Agricultural and Food Chemistry, 61(44): 10604‑10611.