In silico screening for novel anti-COVID phytochemicals from the rhizome of Curcuma longa

The devastating nature of the SARS-CoV-2 pandemic has fostered the need for potent therapeutics to manage or curb its severity. As a response, several studies on drug repurposing, vaccine design and optimizing natural phytochemicals are ongoing. This study aims at screening for potent and novel anti-COVID phytochemicals from the rhizome of Curcuma longa. A phytochemical library of 50 non-ubiquitous bioactive compounds from the rhizome of Curcuma longa was retrieved from Dr. Duke's phytochemical and ethnobotanical database (https://phytochem.nal.usda.gov/phytochem/search). The compounds in the library were docked against the receptor binding domain (RBD) of SARS-CoV-2 (PDB ID: 7EAM_1). Three compounds - Quercetin; 1,7-Bis-(4-hydroxyphenyl)-1-heptene-3,5-dione; and Cyclocurcumin, were selected based on their higher docking score than the standard repurposed drug (Arbidol). This study further examined the interactions of the novel 1,7-Bis-(4-hydroxyphenyl)-1-heptene-3,5-dione (BHHD) in the binding pocket as well as its ADMET properties. Excellent interaction was observed between the atoms of BHHD and amino acid residues known to foster the viral entry into the host. Furthermore, the ADMET result for BHHD was impressive for a lead molecule. Therefore, this study recommends for further investigation on the potency and toxicity of BHHD both on cell lines and animal models.