@article{498ab404edfa49978c77fb0ce6a3b4e8,
title = "Inhibition of SARS-CoV 3C-like protease activity by theaflavin-3,3′- digallate (TF3)",
abstract = "SARS-CoV is the causative agent of severe acute respiratory syndrome (SARS). The virally encoded 3C-like protease (3CLPro) has been presumed critical for the viral replication of SARS-CoV in infected host cells. In this study, we screened a natural product library consisting of 720 compounds for inhibitory activity against 3CLPro. Two compounds in the library were found to be inhibitive: tannic acid (IC50 = 3 μM) and 3-isotheaflavin-3-gallate (TF2B) (IC50 = 7 μM). These two compounds belong to a group of natural polyphenols found in tea. We further investigated the 3CLPro-inhibitory activity of extracts from several different types of teas, including green tea, oolong tea, Puer tea and black tea. Our results indicated that extracts from Puer and black tea were more potent than that from green or oolong teas in their inhibitory activities against 3CLPro. Several other known compositions in teas were also evaluated for their activities in inhibiting 3CLPro. We found that caffeine, (-)-epigallocatechin gallte (EGCg), epicatechin (EC), theophylline (TP), catechin (C), epicatechin gallate (ECg) and epigallocatechin (EGC) did not inhibit 3CLPro activity. Only theaflavin-3,3′-digallate (TF3) was found to be a 3CLPro inhibitor. This study has resulted in the identification of new compounds that are effective 3CLPro inhibitors.",
author = "Chen, {Chia Nan} and Lin, {Coney P.C.} and Huang, {Kuo Kuei} and Chen, {Wei Cheng} and Hsieh, {Hsin Pang} and Liang, {Po Huang} and Hsu, {John T.A.}",
note = "Funding Information: Chen Chia-Nan 1 Lin Coney P. C. 1 Huang Kuo-Kuei 1 Chen Wei-Cheng 1 Hsieh Hsin-Pang 1 Liang Po-Huang 2 Hsu John T.-A. tsuanhsu@nhri.org.tw 1,3 1 Division of Biotechnology and Pharmaceutical Research National Health Research Institutes, Taipei Taiwan nhri.org.tw 2 Institute of Biological Chemistry Academia Sinica, Taipei Taiwan wsu.edu 3 Department of Chemical Engineering National Tsing Hua University, Hsinchu Taiwan nthu.edu.tw 2005 2 2 209 215 30 9 2004 11 3 2005 2005 Copyright {\textcopyright} 2005 Chia-Nan Chen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. SARS-CoV is the causative agent of severe acute respiratory syndrome (SARS). The virally encoded 3C-like protease (3CLPro) has been presumed critical for the viral replication of SARS-CoV in infected host cells. In this study, we screened a natural product library consisting of 720 compounds for inhibitory activity against 3CLPro. Two compounds in the library were found to be inhibitive: tannic acid (IC50 = 3 µM) and 3-isotheaflavin-3-gallate (TF2B) (IC50 = 7 µM). These two compounds belong to a group of natural polyphenols found in tea. We further investigated the 3CLPro-inhibitory activity of extracts from several different types of teas, including green tea, oolong tea, Puer tea and black tea. Our results indicated that extracts from Puer and black tea were more potent than that from green or oolong teas in their inhibitory activities against 3CLPro. Several other known compositions in teas were also evaluated for their activities in inhibiting 3CLPro. We found that caffeine, (—)-epigallocatechin gallte (EGCg), epicatechin (EC), theophylline (TP), catechin (C), epicatechin gallate (ECg) and epigallocatechin (EGC) did not inhibit 3CLPro activity. Only theaflavin-3,3′-digallate (TF3) was found to be a 3CLPro inhibitor. This study has resulted in the identification of new compounds that are effective 3CLPro inhibitors. natural products; 3CLPro; black tea; TF2B; TF3 http://dx.doi.org/10.13039/501100001868 National Science Council Taiwan NSC92-2751-B-400-006-Y http://dx.doi.org/10.13039/501100001868 National Science Council Taiwan NSC92-2751-B-001–012-Y National Health Research Institutes of Taiwan ",
year = "2005",
month = jun,
doi = "10.1093/ecam/neh081",
language = "English",
volume = "2",
pages = "209--215",
journal = "Evidence-based Complementary and Alternative Medicine",
issn = "1741-427X",
publisher = "Hindawi Publishing Corporation",
number = "2",
}