Sterols from Cucurbita maxima (Duch.) and terpenoids from Schefflera odorata (Blanco)

• Main Author: Lim, Kathleen Y.
• Format: text
• Language: English
• Published: Animo Repository 2003
• Subjects: Terpenes > Spectra; Sterols; Plant products; Squashes; Medicinal plants
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/3078
• Institution: De La Salle University

Two medicinal plants, Cucurbita maxima Duch. commonly known as kalabasa and Schefflera odorata Blanco, also known as five fingers were studied for their chemical constituents. The air-dried flowers of cucurbita maxima (Duch.) afforded a 4:1 mixture of spinasterol and 24-ethyl-5a-cholesta-7, 22, 25-trien-3B-ol, by silica gel column chromatography. Their structures were elucidated by extensive 1D and 2D NMR spectroscopy. This is the first report on the complete 1H-NMR assignments of spinasterol and the complete 1H and 13C-NMR assignments of 24-ethyl-5a-cholesta-7, 22, 25-trien-3B-ol. This is the first time that 24-ethyl-5a-cholesta-7, 22, 25-trien-3B-ol was identified from the plant. The mixture of sterols was tested for antimicrobial activity against seven microorganisms. Results of the study indicated that it has low activity against the fungi Aspergillus niger and Candida albicans with activity index (AI) of 0.3 and the bacteria Bacillus subtilis and Pseudomonas aeruginosa with AI of 0.2. It was found inactive against the bacteria Escherichia coli, and Staphylococcus aureus, and the fungus Trichophyton mentagrophytes. The air-dried leaves of Schefflera odorata (Blanco) afforded oleanolic acid, lutein, fatty alcohols and hydrocarbons, by silica gel column chromatography. The structure of oleanolic acid was elucidated by extensive 1D and 2D NMR spectroscopy. This is the first report on the complete 1H and 13C-NMR assignments of oleanolic acid. Lutein was identified by comparison of its 1H-NMR spectral data with those found in the literature. The fatty alcohols and hydrocarbons were identified by 1H-NMR spectral analysis.