Isolation, Identification Of Flavonoid Components And Antioxidant Activities Determination From Morinda Citrifolia (Mengkudu) And Premna Serratifolia (Bebuas)

Author

SAIDATUL HUSNI BINTI SAIDIN

Date

2005

Keyword

Morinda citrifolia, Premna serratifolia,chemical isolation, flavonoids, antioxidant activity, Quercetin

Abstract

Nine flavonoid components were successfully isolated and identified from the leaves of Morinda citrifolia and Premna serratifolia. Five of the flavonoid components isolated from Morinda citrifolia were quercetin 3,7-O-dimethyl ether, quercetin 3-O-methyl ether, kaempferol 3,4'-0-dimethyl ether, kaempferol 5,7-O-diarabinoside and apigenin. While the other four identified flavonoid components are from Premna serratifolia leaves; luteolin 7-0-methyl ether, apigenin 5,7-O-dimethyl ether and two flavone C-glycoside derivatives. The isolation of flavonoid components were done by paper chromatography method using four different system solutions; BAW (n-butanol:acetic acid:water; 4:1:5), 15% acetic acid, BEW (n-butanol:ethanol:water; 4:1:2.2) and water. Flavonoid was identified through their colors under ultra violet (UV) with/without ammonia vapor, Rf values, acid hydrolysis to aglycone and sugar, co-chromatographic comparison with standard markers and spectral analysis by using a series of shift reagents; (NaOAc + H3BO3), NaOH and (AICI3+2N HCI). All the identified flavonoid components were new findings and never reported before for the same plants. The antioxidant activities for each flavonoid components were evaluated by using ß-carotene bleaching method. Butylated hydroxyl toluene (BHT) and quercetin were used as positive standard markers. Results from the study showed all isolated flavonoid components had antioxidant activities at the 40th minute. Quercetin 3-O-methyl ether has the highest antioxidant activities, 77.67% and were followed by quercetin 3,7-0-dimethyl ether (77.00%), luteolin 7-O-methyl ether (74.10%), kaempferol 3,4'-0-dimethyl ether (66.47%), apigenin (58.10%), kaempferol 5,7-0-diarabinoside (56.14%), apigenin 5,7-O-dimethyl ether (38.10%), flavone-C-glycoside from P. serratifolia petroleum ether extract (35.70%) and flavone-C-glycoside from P. serratifolia chloroform extract (21.47%). Statistic tests were done by using One-way ANOVA and post-hoc test, Tukey; from SPSS version 11.0 software showed all mean antioxidant activities belong to the flavonoid components were significantly different from BHT and quercetin antioxidant activites (p < 0.05).