Secondary Metabolites from Calophyllum nodosum and their Antibacterial Activity
| dc.contributor.author | Yiizamy bin Suffian | |
| dc.date.accessioned | 2026-06-11T03:32:40Z | |
| dc.date.issued | 2026 | |
| dc.description | Utilising natural resources to discover compounds with antibacterial potential is crucial in addressing the growing threat of antibiotic resistance. The Calophyllum genus has gained attention for its diverse secondary metabolites, particularly xanthones with notable pharmacological activities. This study aimed to investigate the phytochemical profile and antibacterial potential of Calophyllum nodosum stem bark, given the well-documented therapeutic potential of the genus in antibacterial activity. The dried, ground stem bark was extracted using a maceration technique with different solvents of n-hexane, chloroform, and methanol sequentially, followed by filtration to obtain respective extracts. The compounds were isolated and purified using various chromatographic techniques and characterised through 1D and 2D nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), mass spectrometry (MS), ultraviolet-visible spectroscopy (UV-Vis), and melting point analysis. Seven compounds were successfully isolated, including nodosuxanthone (89), a newly undescribed xanthone, trapezifolixanthone (20), caloxanthone C (5), 1-hydroxy-7-methoxyxanthone (27), canumolactone (90), friedelin (71), and stigmasterol (70). The antibacterial activity of the extracts and isolated compounds was evaluated against Gram-positive bacteria and Gram-negative bacteria (Acinetobacter baumannii, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli) using the well-diffusion method, followed by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Caloxanthone C (5) and canumolactone (90) exhibited the most potent antibacterial activities as both compounds demonstrated comparable activity with ampicillin against A. baumannii and E. coli (MIC = 0.025 mg/mL; MBC = 0.05 – 0.1 mg/mL). Notably, both compounds demonstrated strong activity against P. aeruginosa, surpassing the inhibitory effect of ampicillin under the tested conditions. As for the extracts, the n-hexane extract displayed moderate activity (MIC = 0.25 mg/mL) against A. baumannii, E. coli, and K. pneumoniae with MBC values of 1.0 mg/mL, 1.0 mg/mL, and 0.5 mg/mL against the three bacterial strains, respectively. Remarkably, this study reports the first natural occurrence of nodosuxanthone (89), contributing to the (iv) growing knowledge of Calophyllum-derived bioactive compounds and supporting the potential of Calophyllum species as a valuable source for novel antibacterial candidates. | |
| dc.identifier.uri | https://scholarhub.unimas.my/handle/123456789/843 | |
| dc.language.iso | English | |
| dc.publisher | Universiti Malaysia Sarawak | |
| dc.relation.ispartofseries | Faculty of Resource Science and Technology | |
| dc.subject | Calophyllum nodosum, secondary metabolites, isolation, nodosuxanthone, antibacterial. | |
| dc.title | Secondary Metabolites from Calophyllum nodosum and their Antibacterial Activity | |
| dc.type | Masters |