ISOLATION OF ANTIOXIDANT COMPOUNDS FROM MUGWORT HERB (ARTEMISIA VULGARIS} L.) AND COMPARISON OF ANTIOXIDANT ACTIVITIES FOUR HERB PLANTS ASTERACEAE FAMILY USING DPPH AND FRAP METHODS

• Main Author: Nadia Halim, Evelyne
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/78926
• Institution: Institut Teknologi Bandung

Reactive oxygen species (ROS) from both endogenous and exogenous sources may be involved in the etiologies Of various human's diseases such as atherosclerosis, cancer, neurodegenerative diseasev inflammation process, and aging. Many evidences show that natural antioxidant may be usefial in preventing the deleterious consequences from oxidative stress. Based on researches, several wild plants of Asteraceae family had been proved as having antioxidant activity. The objectives of this research were to isolate, characterize, and identify antioxidant compounds from mugwort (Artemisia vulgaris L.) herb; also to determine antioxidant activities from four herb of Asteraceae plants (A. vulgaris L., Bidens pilosa L., Ageratum conyzoides L. , and Sonchus arvensis L.) using 2,2diphenyl-l-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) methods, and their correlations with the total phenolic, flavonoid, and carotenoid contents. Crude drug of all herbs were extracted by reflux apparatus using three solvents with increasing polarity: n-hexane, ethyl acetate, and methanol. Twelve extracts were monitored by thin layer chromatography (TLC), their antioxidant activities were tested by DPPH and FRAP methods; their half minimum inhibitory concentration (IC50) of DPPH, half mmimum exhibitory concentration (EC50) of FRAP, total phenclic, flavonoid, and carotenoid contents were also determined. Ethyl acetate extract of A. vulgaris herb was chosen to the next step, which was fractionated by vacuum liquid chromatography (VLC). Fraction 7 from VLC was fractionated using radial chromatography with gradient elution system. The chosen subfraction was purified by radial chromatography with isocratic elution system to obtain isolate A. Fraction 8 and 9 from VLC were simplified using VLC and subfraction 7-9 were chosen to simplified using radial chromatography. Purification was done by paper chromatography preparative so that isolate B and C were yielded. Subfraction 4 from VLC was simplified using radial chromatography and washed with methanol to obtain isolate D. The purity of isolate A, B, C, and D were tested by single-development system TLC using three mobile phases with different polarity and two-dimensional TLC. All compounds were characterized by TLC using specific spray reagents, ultravioletvisible spectrophotometry, infrared spectrophotometry, proton nuclear magnetic resonance spectroscopy, and carbon nuclear magnetic resonance spectroscopy. The ethyl acetate extract of B. pilosa herb had the highest DPPH scavenging activity and FRAP capacity which were 36.54+0.14% and 68.09±0.04%, respectively. Methanolic extract of B. pilosa herb had the lowest ICso of DPPH scavenging activity which was 76.25±0.26 gg/mL and ethyl acetate extract of B pilosa herb had the lowest EC50 of FRAP capacity which was 33.50±0.04 ug/mL. The highest of total phenolic, flavonoid, and carotenoid contents were achieved by methanolic extract of B. pilosa herb, ethyl acetate extract of B. pilosa herb, and ethyl acetate extract of S arvensis herb which were 7.61+0.01 g GAE/IOO g, 14.66±0.06 g QE/IOO g, and 11.92±0.02 g BE/IOO g, respectively. Four antioxidant compounds were successfully isolated from the ethyl acetate extract of A. vulgaris herb. Isolate A was a terpenoid compound, isolate B, C, and D were flavonoid compunds. Statistically, DPPH scavenging activities, FRAP capacities, IC50 of DPPH, EC50 of FRAP among the n-hexane, ethyl acetate, and methanolic extracts were significantly different (p<0.05). The total phenolic, flavonoid, and carotenoid contents among the n-hexane, ethyl acetate, and methanolic extracts were significantly different (p<0.05). The total phenolic content in the extracts had high and significant correlation with their DPPH scavenging activities and FRAP capacities (p<0.01). The FRAP capacities in all extracts of four herbs had the linear result with DPPH scavenging activitiev Isolate A was a terpenoid compound, isolate B was predicted to be 4',7-dihydroxyflavone, isolate C was predicted to be 3',4'-dihydroxyflavone, and isolate D was supposed to be pinostrobin.