Robinetin for COVID-19

 Robinetin has been reported as potentially beneficial for COVID-19 in the following studies.
COVID-19 involves the interplay of 350+ viral and host proteins and factors providing many therapeutic targets. Scientists have proposed 10,000+ potential treatments. c19early.org analyzes 210+ treatments. We have not reviewed robinetin in detail.
Jin et al., Structure-Based Discovery of the SARS-CoV-2 Main Protease Noncovalent Inhibitors from Traditional Chinese Medicine, Journal of Chemical Information and Modeling, doi:10.1021/acs.jcim.3c01327
Khamto et al., Discovery of Galloyl–Flavonoid Conjugates as SARS-CoV-2 3CLpro Inhibitors: Understanding Binding Interactions Through Computational Approaches, International Journal of Molecular Sciences, doi:10.3390/ijms26199742
The emergence of SARS-CoV-2 in 2019 posed significant global public health challenges. One of the most promising targets for novel antiviral drug development is the SARS-CoV-2 main protease (3CLpro). In this study, fragment molecular orbital (FMO) calculations were conducted to provide guidance for the structural modification of natural flavonoids, identifying the pyrogallol moiety as a key candidate. Natural flavonoids were chemically modified to generate 33 semi-synthetic derivatives through the introduction of various functional groups. Our findings revealed that the incorporation of a galloyl moiety significantly enhances anti-proteolytic activity against SARS-CoV-2 3CLpro, achieving up to a 23-fold increase compared to the activity of the parent compounds. Notably, 7-O-galloyl-DMC (40) exhibited the highest anti-proteolytic activity in an enzymatic assay. Additionally, molecular dynamics simulations provided atomic-level insights into the interactions between the galloyl moiety and 3CLpro. All galloylated flavonoid derivatives positioned their galloyl groups within the S1′ sub-pocket, facilitating hydrogen bonding and π-interactions, particularly with Thr26 and Leu27. These findings underscore the potential of the galloyl moiety as a crucial structural element for enhancing the binding affinity of flavonoids with inhibitory activity against SARS-CoV-2 3CLpro.
Krüger et al., Discovery of Polyphenolic Natural Products as SARS-CoV-2 Mpro Inhibitors for COVID-19, Pharmaceuticals, doi:10.3390/ph16020190
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has forced the development of direct-acting antiviral drugs due to the coronavirus disease 2019 (COVID-19) pandemic. The main protease of SARS-CoV-2 is a crucial enzyme that breaks down polyproteins synthesized from the viral RNA, making it a validated target for the development of SARS-CoV-2 therapeutics. New chemical phenotypes are frequently discovered in natural goods. In the current study, we used a fluorogenic assay to test a variety of natural products for their ability to inhibit SARS-CoV-2 Mpro. Several compounds were discovered to inhibit Mpro at low micromolar concentrations. It was possible to crystallize robinetin together with SARS-CoV-2 Mpro, and the X-ray structure revealed covalent interaction with the protease’s catalytic Cys145 site. Selected potent molecules also exhibited antiviral properties without cytotoxicity. Some of these powerful inhibitors might be utilized as lead compounds for future COVID-19 research.