An L-theanine derivative targets against SARS-CoV-2 and its Delta and Omicron variants.

Abstract

Recent research efforts have shown that tea has activities against SARS-CoV-2. However, the active compounds and the action mechanisms are largely unknown. Here we study the inhibitory potential of L-theanine from tea and its semi-synthesized derivative, a small-molecule fluorescent compound, ethyl 6-bromocoumarin-3-carboxylyl L-theanine (TBrC) against infection and replication of SARS-CoV-2 and the underlying mechanisms of action. We reveal that TBrC has potential activities against SARS-CoV-2 in addition to its activity against lung cancer. TBrC showed extracellular inhibition of SARS-CoV-2 Mpro/3CL and the host cell receptor ACE2 while interacting with the viral spike glycoproteins (wild-type, Delta, and Omicron mutants). Moreover, TBrC and L-theanine significantly suppressed growth and TNFα-induced nuclear transcriptional activation of NF-κB in human lung cancer cells without affecting the viability of normal lung cells, suggesting a potential protection of TBrC and L-theanine from pulmonary damages in SARS-CoV-2 infected patients, especially for lung cancer patients with SARS-CoV-2 infection.

• Authors: Jing Lu, Ying Zhang, Dan Qi, Chunyan Yan, Benhao Wu, Jason H Huang, Jianwen Yao, Erxi Wu, Guoying Zhang
• Journal: Heliyon (Heliyon) Vol. 8 Issue 6 Pg. e09660 (Jun 2022) ISSN: 2405-8440 [Print] England
• PMID: 35706933 (Publication Type: Journal Article)
• Copyright: © 2022 The Author(s).