Please use this identifier to cite or link to this item:
Title: Effects of tannins from Geum japonicum on the catalytic activity of thrombin and factor Xa of blood coagulation cascade
Authors: Dong, H. 
Chen, S.-X. 
Kini, R.M. 
Xu, H.-X.
Issue Date: Nov-1998
Citation: Dong, H., Chen, S.-X., Kini, R.M., Xu, H.-X. (1998-11). Effects of tannins from Geum japonicum on the catalytic activity of thrombin and factor Xa of blood coagulation cascade. Journal of Natural Products 61 (11) : 1356-1360. ScholarBank@NUS Repository.
Abstract: Bioassay-guided fractionation of the MeOH extract of the whole plant of Geum japonicum led to the isolation of seven known tannins. They were identified by spectroscopic methods as penta-O-galloyl-β-glucoside (1); pedunculagin (2), 2,3-(S)-hexahydroxydiphenoyl-D-glucose (3), tellimagrandin II (4), 2,6-di-O-galloyl-D-glucose (5), casuariin (6), and 5- desgalloylstachyurin (7). Compounds 1, 2, 4, 6, and 7 showed potent anticoagulant activity by significantly prolonging the clotting of rabbit plasma. The inhibitory effect of 2 was competitively directed against thrombin. Its IC50 values for inhibition of the enzymatic activity of thrombin on synthetic substrate and fibrinogen were 0.18 and 0.15 μM, respectively. On the other hand, compounds 1, 4, 6, and 7 are mixed noncompetitive inhibitors of thrombin. Their IC50 values for inhibition of fibrinogen hydrolysis were twofold to sevenfold lower than those for the inhibition of synthetic substrate hydrolysis. Factor Xa was competitively inhibited by compounds 1, 2, 4, 6, and 7. The phenolic hydroxyl groups of the active tannins appear to play an important role in their inhibitory effect on the enzymes.
Source Title: Journal of Natural Products
ISSN: 01633864
DOI: 10.1021/np9801458
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.


checked on Nov 23, 2020


checked on Jul 3, 2019

Page view(s)

checked on Nov 21, 2020

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.