Investigation of chemical compositions, antioxidant and antimicrobial activities of pomelo seed extracts

Abstract

In the present study, the natural compounds existed in seeds of three pomelo varieties grown in the South of Vietnam were extracted by methanol solvent and characterized for their chemical compositions, antioxidant and antimicrobial activities. Using LC-MS, six compounds, including nomilinic acid glucoside (4.93- 6.52%), nomilin glucoside (5.58- 10.13%), obacunone glucoside (1.23- 2.99%), limonoate A-ring lactone (0.73- 1.78%), limonin (11.07- 19.12%), nomilin (1.96-4%), were determined with the total concentrations of from 28.63 to 39.68%. Three kinds of pomelo seed extracts showed strong antioxidant, whereas these extracts had the weak antimicrobial activities. Briefly, the antioxidant capacity, expressed by IC50, of Da Xanh, Day and Duong Hong pomelos were 0.624, 0.436, 0.352 mg/ml, respectively. The results also indicated that seed extracts exhibited week inhibition on the gram-positive microorganisms (S. aureus, B. cereus and B. subtilis), while no inhibition on the gram-negative microorganisms (S. typhi, P. aeruginosa and E. coli). Key words: Pomelo seed Chemical compositions Antioxidant activity Antimicrobial activity