Triterpenoids and other metabolites from the hexane extract of Pipturus arborescens

• Main Author: Gabona, Marissa G.
• Format: text
• Language: English
• Published: Animo Repository 2000
• Subjects: Terpenes; Plant metabolites; Extracts; Microbial sensitivity tests; Hexane; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/2345
• Institution: De La Salle University

This thesis studies the secondary metabolites from the hexane extract of Pipturus arborescens leaves and the antimicrobial potential of the alkaloids from Prosopis vidaliana leaves.The crude methanolic extract of Pipturus arborescens leaves was partitioned between nonpolar (hexane) and polar (methanol) solvents. Chromatographic separation of the hexane extract and purification by rechromatography or recrystallization made possible the isolation of three pure compounds. These compounds were characterized as triterpenes from their mass spectral and NMR data. The triterpenes were identified as glutinone, friedelin and glutinol by comparison of their spectral properties from those in the literature. A mixture of common plant sterols: campesterol, stigmasterol and sitosterol were also identified by GC-MS technique.Antimicrobial test using the broth dilution method conducted on glutinone indicated significant activity against Pseudomonas aeruginosa, a multidrug resistant microorganism, at 50 ug/ml. Infections caused by this microorganism are often malignant and resistant to therapy. This indicates the anti-pseudomonal potential of glutinone. The compound also exhibited weaker activity against Staphylococcus aureus and Escherichia coli (100 ug/ml). The antimicrobial property of glutinone has not been previously reported. Antimicrobial test conducted on friedelin and glutinol indicated no activity against S. aureus, E. coli and P. aeruginosa. Antibacterial tests conducted on extracts of Prosopis vidaliana leaves showed that its antibacterial property may be attributed to its alkaloid content. Selected fractions from the chromatographic separation of the crude alkaloid indicated antibacterial activity against S. aureus at less than or equal to 12.5 ug/ml. Thus, P. vidaliana is a potential source of compounds against skin infections.