In Silico Docking Study of Guttiferones; Q-S from Malabar Tamarind Fruit Rind Against SARS-Cov-2 Omicron Spike Protein with Evaluation of Antioxidant Potential, Phenolic Content and HPTLC Fingerprinting of Its Total Extract

Abstract

Abstract (1) Background: The Omicron variant of SARS-CoV-2 has rapidly spread and is now the predominant variant worldwide. Its key feature is its ability to evade immunity from natural infection or vaccines, owing to its numerous mutations in the spike protein. In contrast, medicinal plants have been utilized as alternative therapies to alleviate certain signs and symptoms associated with COVID-19. In this study; Malabar tamarind, which belongs to the Clusiaceae family, was studied for HPTLC fingerprint for its total methanolic extract, quantitative determination of its total phenolics and flavonoids, in-vitro evaluation of its antioxidant potential, followed by molecular docking study of three of its reported natural metabolites; Guttiferones Q, R and S, in order to measure their affinity against the target site of the SARS-CoV-2 Omicron Spike Protein (2) Methods: Total phenolic content was evaluated by Folin-Catechu assay, flavonoids by aluminum chloride assay. Antioxidant potential was estimated by DPPH assay, while the in silico docking study was processed with the use of Azithromycin as a reference drug (3) Results: Tamarind exhibited a free radical-scavenging activity of 71.75 % inhibition. The molecular docking results suggested that Guttiferone R has the highest binding affinity, alongside predicted binding energy of -8.67 kcal/mol and an RMSD value of 1.07 Å compared to Azithromycin, a reference compound, which has binding affinity of -8.90 kcal/mol and an RMSD value of 1.20 Å. (4) Conclusions: Guttiferone R has the strongest potential as a drug candidate, based on its high binding affinity and low RMSD value, which suggests that it has a stable binding mode.