[Studies on flavonoids and their antioxidant activities of Artemisia annua].
OBJECTIVE
To study the flavonoids and their antioxidant activities of Artemisia annua.


METHODS
Isolation and purification were carried out by silica gel and Sephadex LH-20 column chromatographies. Compounds were identified by physicochemical properties and spectral analysis, then their antioxidant activities were evaluated by ORAC assay.


RESULTS
Five flavonoids were isolated from the plant. Their structures were identified as 5-hydroxy-3,7,4'-trimethoxyflavone(1), 5-hydroxy-6,7,3',4'-tetramethoxyflavonol(2), blumeatin(3), 5, 4'-dihydroxy-3,7,3'-trimethoxyflavone(4) and quercetin(5), respectively. Compounds 1-5 could slow up the attenuation rate of the fluorescence induced by AAPH.


CONCLUSIONS
Compounds 1-3 are isolated from the plant for the first time. Compounds 1-5 all possess the potential antioxidant activities.
Yang
Guo-en
GE
Department of Phytochemistry, China Pharmaceutical University, Nanjing 210038, China. 200203684@sina.com.cn
Bao
Li
L
Zhang
Xiao-qi
XQ
Wang
Ying
Y
Li
Qian
Q
Zhang
Wei-ku
WK
Ye
Wen-cai
WC
D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D031172:Artemisia annua / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D011794:Quercetin / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
C501183:3',5,6-trihydroxy-3,4',7-trimethoxyflavone; D000975:Antioxidants; D047309:Flavones; D005419:Flavonoids; C084491:blumeatin; C008751:pachypodol; D011794:Quercetin