The Department of Biology at the College of Education for Pure Sciences – Ibn Al-Haitham, University of Baghdad, discussed the Master’s thesis entitled: “Extraction and Partial Purification of Some Active Compounds from Parts of the Jujube Plant Ziziphus spina-christi L. (Dest) and Study of Their Antibacterial Activity against Bacteria Isolated from Skin Infections”
The thesis was submitted by Aseel Hadi Alkum Owaiz, under the supervision of Asst. Prof. Dr. Mohammed Abbas Fayyad. The discussion committee consisted of Prof. Dr. Khalid Hashim Abdulmunim, Chair; Asst. Prof. Dr. Essam Jassim Khraibet, Member; Asst. Prof. Dr. Haifa Nouri Matar, Member; and Asst. Prof. Dr. Mohammed Abbas Fayyad, Member and Supervisor.
The study aimed to extract and partially purify bioactive compounds from different parts of the jujube plant and investigate their antibacterial activity against pathogenic antibiotic-resistant bacterial isolates. The research was motivated by the growing global challenge of antimicrobial resistance and its implications for the management of bacterial infections, particularly those associated with wounds and burns. The study also sought to identify major bioactive chemical constituents in the plant extracts and evaluate their potential to inhibit bacterial growth and biofilm formation.
The research comprised four principal components. The first involved the collection of fresh samples of leaves and fruits of the jujube plant, Ziziphus spina-christi, followed by drying, preparation, and extraction after taxonomic identification of the plant. The second component involved the collection, isolation, and identification of pathogenic bacteria associated with wounds and burns from several hospitals in Baghdad, following the required official approvals. The third component focused on evaluating the antibacterial activity of the plant extracts against multidrug-resistant bacterial isolates and biofilm-forming bacteria. The fourth component involved the chemical characterization of the major bioactive compounds using instrumental analytical techniques, including GC–MS, HPLC, and UV analysis.
Between 12 August 2025 and 9 October 2025, a total of 110 pathogenic bacterial isolates were collected from patients suffering from wound and burn infections. The patients ranged in age from 1.5 to 80 years, allowing the study to encompass a broad range of age groups. Samples were collected using transport-media swabs and transferred to the laboratory under appropriate conditions to preserve bacterial viability and ensure the reliability of subsequent analyses.
Evaluation of the antibacterial activity of the jujube leaf extract demonstrated a clear concentration-dependent inhibitory effect. Statistical analysis using one-way analysis of variance (One-way ANOVA) revealed statistically significant differences among the tested extract concentrations at P≤0.05, with an F-value of 18.47 and an LSD value of 2.15.
The 40% concentration produced the highest mean inhibition-zone diameter of 17.63 mm, compared with 12.50 mm at 20% and 11.25 mm at 10%. These findings indicate a positive relationship between extract concentration and the magnitude of bacterial growth inhibition.
At the level of individual bacterial isolates, isolate Staph11, identified as Staphylococcus aureus, exhibited the largest inhibition zone, reaching 24 mm at a concentration of 40%. This was followed by isolates Staph2 and E9, with inhibition zones of 21 mm for each. In contrast, some isolates of Klebsiella pneumoniae, including K1 and K13, showed relatively weaker responses, with inhibition zones ranging from 7 to 12 mm, while no inhibitory activity was observed at some of the lower concentrations.
The findings also demonstrated that Gram-positive bacteria, particularly Staphylococcus aureus isolates, were more susceptible to the plant extract than Gram-negative bacteria, such as Escherichia coli and Klebsiella pneumoniae. This variation may be associated with differences in bacterial cell-wall architecture and the presence of an additional outer membrane in Gram-negative bacteria, which can affect the permeability and cellular uptake of plant-derived bioactive compounds.
The study further revealed that 31 isolates representing the bacterial species Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus exhibited varying capacities for biofilm formation. The partially purified flavonoid extract also demonstrated inhibitory activity against bacterial growth and biofilm formation at different concentrations, with Gram-positive isolates generally showing greater susceptibility to the extract.
HPLC analysis revealed the presence of several biologically active flavonoid compounds in the extract, including quercetin, rutin, luteolin, kaempferol, and apigenin. These compounds have been associated in the scientific literature with diverse biological activities, including antimicrobial and antibiofilm effects.
Chemical analysis of the plant extracts, particularly the alcoholic extract, also revealed considerable chemical diversity, including phenolic compounds, aldehydes, fatty esters, and methylated sugars. 2-Chloroethyl oleate was the most abundant identified compound, accounting for 35.79%, followed by 3-O-Methyl-D-glucose at 19.11%, Benzenetriol at 17.62%, and Hydroxymethylfurfural at 5.72%. These findings demonstrate the chemical diversity of the extract and suggest that several of its constituents may contribute to the biological activity observed in the study.
Overall, the study concluded that jujube leaf extract exhibits concentration- and isolate-dependent antibacterial activity, in addition to an inhibitory effect on biofilm formation. These findings suggest that Ziziphus spina-christi may represent a promising natural source of bioactive compounds for further investigation as potential antimicrobial agents or as adjuncts to existing antimicrobial therapies. However, the study emphasized the need for further preclinical and toxicological investigations to establish safety, efficacy, and mechanisms of action before any direct therapeutic application can be considered.
The study recommended expanding applied research on jujube plant extracts; isolating and purifying additional bioactive compounds and investigating their mechanisms of action through in vivo studies; determining optimal inhibitory concentrations; comparing plant-extract activity with standard antibiotics; and investigating potential synergistic interactions between plant extracts and conventional antibiotics. It also recommended conducting toxicological studies to assess the safety of the extracts and their constituents, as well as further research into the differences in bacterial susceptibility in relation to cell-wall structure, antimicrobial resistance mechanisms, and biofilm formation.
Contribution to the Sustainable Development Goals
The research contributes to several United Nations Sustainable Development Goals (SDGs), particularly:
SDG 3 – Good Health and Well-Being: by exploring natural sources and bioactive compounds that may contribute to future approaches for combating bacterial infections and antimicrobial resistance.
SDG 9 – Industry, Innovation and Infrastructure: through the application of modern analytical techniques to identify bioactive compounds and investigate their potential for innovative biomedical applications.
SDG 12 – Responsible Consumption and Production: by exploring natural plant resources as potential sources of biologically valuable compounds with future practical applications.
This research reflects the Department of Biology’s and the College of Education for Pure Sciences – Ibn Al-Haitham’s commitment to advancing applied scientific research, exploring natural resources to address contemporary health challenges, and supporting interdisciplinary research at the interface of biological sciences, analytical chemistry, and biomedical applications.
