Heliyon
Volume 8, Issue 6, June 2022, e09660
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Research article
An L-theanine derivative targets against SARS-CoV-2 and its Delta and Omicron variants

https://doi.org/10.1016/j.heliyon.2022.e09660Get rights and content
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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.

Keywords

TBrC
SARS-CoV-2
Mpro/3CL
ACE2
Mutant spike proteins
NF-κB

Cited by (0)

1

Lead contact.

2

Equal first authors.