PHYTOCHEMISTRY AND ANTIBACTERIALS, ANTIFUNGAL, ANTIFEEDANT ACTIVITIES OF SECONDARY METABOLITES FROM Dysoxylum densiflorum AND Swietenia mahogany (MELIACEAE)

• Main Author: KOMANG TRI DHARMAYANI NIM:30512003, NI
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29637
• Institution: Institut Teknologi Bandung

<p align="justify">Meliaceae is one tropical plant widely spreads in Asia, tropical Africa, and Latin America. This plant family consists of 50 genera and 1400 species. In Indonesia there are about 33 genera and 405 species of Meliaceae. Meliaceae is famous for its wood quality since its wood properties are strong, hard, and resistant to termite attack and therefore it is widely used for furniture and building materials. Beside of its wood quality, this plant is also known as traditional medicines to treat skin irritation, to prevent hypertension, to cure urinary tract infections, and fever. Several of Meliaceae plants widely known in Indonesia especially are Dysoxylum densiflorum (‘Majegau’) and Swietenia mahogany (‘Mahoni’). Phytochemically, both of species have been reported as sources of secondary metabolites belong to terpenoids and limonoids groups and several isolated compounds have been reported to have important biological activities, such as antibacterial, antifeedant, antimalarial, antiinflammatory, antiviral and insecticide. <br /> <br /> In this research, two species of Meliaceae Indonesia, i.e. D. densiflorum and S. mahogany have been evaluated phytochemically. In addition, biological activities such as antibacterial, antifungal and antifeedant of the extracts and isolated compounds have also been examined. The samples of D. densiflorum bark and seeds were collected from Ekaristi Botanical Garden at Bali, while D. densiflorum leaves were obtained from Bogor Botanical Gardens, West Java, and fruit of S. mahogany were obtained from Bandung area, West Java. The isolation of secondary metabolites was carried out by extraction at room temperature (maceration) using acetone solvent, followed by fractionations and purifications using various chromatography techniques, such as vacuum liquid chromatography (VLC), gravitational column chromatography (GCC), and radial chromatography (RC). The molecular structures of isolated compounds were determined based on spectroscopic data, including 1D NMR (1H NMR, 13C NMR, TOCSY1D, and NOE1D) and 2D NMR (COSY, HSQC, HMBC and NOESY), mass spectrometry (MS) data, and infrared (IR). The antibacterial activity of extracts and isolated compounds were examined against ten pathogenic bacteria including two Gram-(+) bacteria, i.e. Bacillus subtilis and Staphylococcus aureus (ATCC 29737) and eight Gram-(-) bacteria, i.e. Escherichia coli, Klebsiella pneumonia (ATCC 13733), Proteus mirabilis (ATCC 21100), Pseudomonas aeruginosa, Salmonella parathypii, Salmonella thypii (ATCC 14028), Shigella dysentriae, and Vibrio cholereaeus. The antifungal activities have been examined by decay test against brown-rot (Fomitopsis palustris FFPRI 0507) and white-rot (Tremetes versicolor FFPRI 1030). The antifeedantz activity evaluation against termites Captotermes formasanus Shiraki was carried out with no-choice method. <br /> <br /> In this research, eleven terpenoid derivatives(1(rumus)11) have been obtained including four new compounds, namely 4-isopropyl-1,5-dimethyl-1,2,3,4-tetrahydronaphtalene-6-ol (2), densiflorinic acid A (3), densiflorinic acid B (4) and densiflorinic acid C (5). Seven other isolated compounds were known compounds, including one sesquiterpene i.e. 8-hydroxycalamenene (1), one tetracyclic triterpene i.e. aphagranin G (6), and six limonoid compounds, namely proceranolide (7), swietenolide (8), 6-O-acetylswietenolide (9), 3,6-O-acetylswietenolide (10), and swietenin (11). The finding of four new compounds gives important contribution to the phytochemical aspect of Meliaceae. Compound (2) is sesquiterpene having modified cadinane skeleton caused by methyl rearrangements. Densiflorinic acids A-C (3-5) are tetracyclic triterpenes having tirucalane and apotirucalane skeletal which become the precursor of limonoids in Meliaceae plants. In addition, a tetracyclic triterpene i.e. aphraganin (6) is reported for the first time from Dysoxylum. <br /> <br /> Biological activity of D. densiflorum extracts showed significant result against ten bacteria (MIC 3.13-25µg/mL) compared to control amoxicillin and chloramphenicol (MIC 0.78-50 µg/mL) as positive controls. Antibacteria activity of D. densiflorum extracts had better activities against Gram-(+) bacteria than Gram-(-) bacteria. Decay test of D. densiflorum extracts showed inhibition activity against rot fungi, while the extracts had positive results with concentration range 5-30% (w/v) for antifeedant activity. Next, S. mahogany extracts showed moderate antibacterial activity (MIC 50-100 µg/mL), but they were active against rot fungi and strong activity in antifeedant activity assay with concentration range 5-30% (w/v). Based on these results, D. densiflorum and S. mahogany extracts have potency as antibacterial, antifungal and antifeedant activities. <br /> <br /> The isolated compounds (1(rumus)11) were also examined on antibacterial, antifungal and antifeedant assays. Based on those three assays, only compound 1 and 2 that showed significant results on antibacterial activity (MIC 6.25-25 µg/mL), antifungal activity (inhibitory zone exist) and antifeedant activity (concentration 100-1000 ppm), while compounds 3(rumus)11 are relatively inactive as antibacterial, antifungal or antifeedant. The activity of compound 1 and 2 could be caused by the present of phenolic group in their sesquiterpenes structures that was not be possessed by other compounds (3-11). <br /> <br /> In conclusion, in this research eleven terpenoid derivatives (compound 1-11) were successfully isolated from D. densiflorum and S. mahogany extracts including four new compounds of sesquiterpene (compound 2) and tetracyclic triterpenes derivatives (compounds 3-5). The biological activities including antibacterial, antifungal and antifeedant of D. densiflorum and S. mahogany extracts showed significant results. The significant results of isolated compounds only showed on compound 1 and 2. The difference between results activities of extracts and isolated compounds suggest that there are maybe still several compounds that have not yet been isolated yet which are probably having responsibility on the activities of the extracts.<p align="justify">