Isolation and structure elucidation of some secondary metabolites from Averrhoa bilimbi Linn. and their bioactivities

• Main Author: Gunawan
• Format: text
• Language: English
• Published: Animo Repository 2011
• Subjects: Averrhoa—Analysis; Metabolites; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/6574; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/12974/viewcontent/CDTG004942_P.pdf
• Institution: De La Salle University

Averrhoa bilimbi Linn samples were collected from Tanauan, Philippines was studied to determine some of its secondary metabolites and their bioactivity. The DCM extract obtained from the crude methanolic extract of the leaves were fractionated by column chromatography and purified by re-chromatography and re-crystallized or washed. Seven isolates were obtained from the extract of leaves: squalene (31) for LD2.1.2; 3-(6,10,14-trimethylpentadecan-2-yl)furan-2(5H)-one (33; new compound) for LD2.6.2; 2,3-bis (-2,6,10-trimethylundeca-1,5,9-trienyl)oxirane (34; new compound) for LD4.3.3; phytol (32) for LD4.4.3; 3,4-dihydroxyhexanedioic acid (35; first time isolated from natural source) for LD6.5.3; malonic acid (36) for LD6.11.1 and 4,5-dihydroxy-2-methoxybenzaldehyde (37) for LMEA3.3. Isolation and purification of A. bilimbi (L.) fruits afforded oxalic acid (4) from fruit EtOAc extract (FMEA) and 2,4-dihydroxy-6-((4-methylpentyloxy)methyl)benzaldehyde (39; new compound) for FMA6. The structure of these compounds was elucidated from their 1D NMR (1H NMR, 13C NMR and 13C DEPT NMR) and 2D NMR (COSY, HSQC and HMBC) data as well as mass spectral data (EIMS and ESMS). The ethyl acetate extract (LE) from leaves proved to be the most active as compared to the other extracts. Extract LE showed very strong antioxidant activity (IC50 = 48.91 ppm) while others extracts were weakly active or completely inactive.