Free radical scavenging and antielastase activities of flavonoids from the fruits of Thuja orientalis.
Bioassay-guided fractionation of the MeOH extract of Thuja orientalis fruits using a DPPH (2,2-diphenyl-1-picrylhydrazyl) assay led to the isolation of 9 flavonoids: cupressuflavone (1), amentoflavone (2), robustaflavone (3), afzelin (4), (+)-catechin (5), quercitrin (6), hypolaetin 7-O-beta-xylopyranoside (7), isoquercitrin (8) and myricitrin (9). Their chemical structures were determined by spectroscopic analyses. The free radical scavenging and human neutrophil elastase (HNE) inhibitory activities were evaluated for the isolated compounds. By DPPH scavenging assay, compounds 5, 6, 7, 8 and 9 showed anti-oxidant activities with IC(50) values of 28.66, 31.19, 18.30, 26.63 and 15.10 microM, respectively. By ABTS [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] scavenging assay, these compounds also exhibited potent anti-oxidant activities with IC(50) values of 6.77, 13.96, 6.97, 22.79 and 9.96 microM, respectively. Of note, compounds 1, 2 and 3 showed significant HNE inhibitory activities with IC(50) values of 8.09, 1.27 and 1.33 microM, respectively.
Xu
Guang-Hua
GH
Functional Metabolite Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea.
Ryoo
In-Ja
IJ
Kim
Young-Hee
YH
Choo
Soo-Jin
SJ
Yoo
Ick-Dong
ID
D052160:Benzothiazoles; D001713:Biphenyl Compounds / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D009504:Neutrophils / Q000201:enzymology; D010084:Oxidation-Reduction; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors*; D010851:Picrates / Q000737:chemistry; D013451:Sulfonic Acids / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry; D029783:Thuja / Q000737:chemistry*
D052160:Benzothiazoles; D001713:Biphenyl Compounds; D004791:Enzyme Inhibitors; D005419:Flavonoids; D016166:Free Radical Scavengers; D010851:Picrates; D013451:Sulfonic Acids; D013844:Thiazoles; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D010196:Pancreatic Elastase