Isolation, structural elucidation and molecular docking studies against SARS-CoV-2 main protease of new stigmastane-type steroidal glucosides isolated from the whole plants of Vernonia gratiosa

• Published in: Natural product research 2023-07, Vol.37 (14), p.2342-2350
• Main Authors: Van Cong, Pham, Anh, Hoang Le Tuan, Trung, Nguyen Quang, Quang Minh, Bui, Viet Duc, Ngo, Van Dan, Nguyen, Trang, Nguyen Minh, Phong, Nguyen Viet, Vinh, Le Ba, Anh, Le Tuan, Lee, Ki Yong
• Format: Article
• Language: English
• Subjects: Binding sites; Chemical reactions; Glucosides; Molecular docking; NMR; Nuclear magnetic resonance; Protease; Proteinase; Replicase; SARS-CoV-2 main protease; Severe acute respiratory syndrome coronavirus 2; stigmastane-type steroidal glucoside; Substrates; Two dimensional analysis; Vernonia; Vernonia gratiosa
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2022.2042534

Phytochemical investigation of the whole plants of Vernonia gratiosa Hance. led in the isolation and identification of two new stigmastane-type steroidal glucosides (1-2), namely vernogratiosides A (1), and B (2). Their chemical structures were fully elucidated based on 1 D/2D NMR spectroscopic, HR-ESI-MS data analyses, and by producing derivatives by chemical reactions. The binding potential of the isolated compounds to replicase protein − main protease of SARS-CoV-2 were examined using the molecular docking simulations. Our results show that the isolated steroidal glucosides (1-2) bind to the substrate-binding site of SARS-CoV-2 main protease with binding affinities of −7.2 and −7.6 kcal/mol, respectively, as well as binding abilities equivalent to N3 inhibitor that has already been reported (-7.5 kcal/mol).