Glycyrrhizic Acid Derivatives Bearing Amino Acid Residues in the Carbohydrate Part as Dengue Virus E Protein Inhibitors: Synthesis and Antiviral Activity

Mann-Jen Hour; Yeh Chen; Chen-Sheng Lin; Lidia A Baltina; Ju-Ying Kan; Yan-Ting Tsai; Yan-Tung Kiu; Hsueh-Chou Lai; Lia A Baltina; Svetlana F Petrova; Cheng-Wen Lin

doi:10.3390/ijms231810309

Glycyrrhizic Acid Derivatives Bearing Amino Acid Residues in the Carbohydrate Part as Dengue Virus E Protein Inhibitors: Synthesis and Antiviral Activity

Int J Mol Sci. 2022 Sep 7;23(18):10309. doi: 10.3390/ijms231810309.

Authors

Mann-Jen Hour¹, Yeh Chen², Chen-Sheng Lin³, Lidia A Baltina⁴, Ju-Ying Kan⁵, Yan-Ting Tsai^{6

7}, Yan-Tung Kiu⁶, Hsueh-Chou Lai⁸, Lia A Baltina⁴, Svetlana F Petrova⁴, Cheng-Wen Lin^{5

6

7}

Affiliations

¹ School of Pharmacy, China Medical University, Taichung 40402, Taiwan.
² Institute of New Drug Development, China Medical University, Taichung 40402, Taiwan.
³ Division of Gastroenterology, Kuang Tien General Hospital, No. 117 Shatian Road, Shalu District, Taichung 43303, Taiwan.
⁴ Ufa Institute of Chemistry, Ufa Federal Research Centre of RAS, 71 Prospect Oktyabrya, 450054 Ufa, Russia.
⁵ Graduate Institute of Biomedical Sciences, China Medical University, 91, Hsueh-Shin Road, Taichung 40402, Taiwan.
⁶ Department of Medical Laboratory Science and Biotechnology, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan.
⁷ Department of Medical Laboratory Science and Biotechnology, Asia University, 500 Lioufeng Road, Wufeng, Taichung 41354, Taiwan.
⁸ School of Chinese Medicine, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan.

Abstract

Dengue virus (DENV) is one of the most geographically distributed mosquito-borne flaviviruses, like Japanese encephalitis virus (JEV), and Zika virus (ZIKV). In this study, a library of the known and novel Glycyrrhizic acid (GL) derivatives bearing amino acid residues or their methyl/ethyl esters in the carbohydrate part were synthesized and studied as DENV inhibitors in vitro using the cytopathic effect (CPE), viral infectivity and virus yield assays with DENV1 and DENV-2 in Vero E6 and A549 cells. Among the GL conjugates tested, compound hits GL-D-ValOMe 3, GL-TyrOMe 6, GL-PheOEt 11, and GL-LysOMe 21 were discovered to have better antiviral activity than GL, with IC50 values ranging from <0.1 to 5.98 μM on the in vitro infectivity of DENV1 and DENV2 in Vero E6 and A549 cells. Compound hits 3, 6, 11, and 21 had a concentration-dependent inhibition on the virus yield in Vero E6, in which GL-D-ValOMe 3 and GL-PheOEt 11 were the most active inhibitors of DENV2 yield. Meanwhile, the time-of-addition assay indicated that conjugates GL-D-ValOMe 3 and GL-PheOEt 11 exhibited a substantial decrease in the DENV2 attachment stage. Subsequently, chimeric single-round infectious particles (SRIPs) of DENV2 C-prM-E protein/JEV replicon and DENV2 prM-E/ZIKV replicon were utilized for the DENV envelope I protein-mediated attachment assay. GL conjugates 3 and 11 significantly reduced the attachment of chimeric DENV2 C-prM-E/JEV and DENV2 prM-E/ZIKV SRIPs onto Vero E6 cells in a concentration-dependent manner but did not impede the attachment of wild-type JEV CprME/JEV and ZIKV prM-E/ZIKV SRIPs, indicating the inhibition of Compounds 3 and 11 on DENV2 E-mediated attachment. Molecular docking data revealed that Compounds 3 and 11 have hydrophobic interactions within a hydrophobic pocket among the interfaces of Domains I, II, and the stem region of the DENV2 envelope (E) protein. These results displayed that Compounds 3 and 11 were the lead compounds targeting the DENV E protein. Altogether, our findings provide new insights into the structure−activity relationship of GL derivatives conjugated with amino acid residues and can be the new fundamental basis for the search and development of novel flavivirus inhibitors based on natural compounds.

Keywords: Dengue virus; Glycyrrhizic acid; amino acids; antiviral activity; derivatives; methyl/ethyl ester; molecular model; synthesis.

MeSH terms

Amino Acids / metabolism
Animals
Antiviral Agents / metabolism
Antiviral Agents / pharmacology
Carbohydrates
Dengue Virus*
Dengue* / drug therapy
Encephalitis Virus, Japanese*
Encephalitis Viruses, Japanese*
Flavivirus*
Glycyrrhizic Acid / metabolism
Glycyrrhizic Acid / pharmacology
Humans
Molecular Docking Simulation
Zika Virus Infection*
Zika Virus*

Substances

Amino Acids
Antiviral Agents
Carbohydrates
Glycyrrhizic Acid

Grants and funding

This work was supported by the Russian Science Foundation (Grant RSF-MOST No. 22-43-08002, https://rscf.ru/project/22-43-08002/) (a chemical part, synthesis, HPLC and NMR analysis), the National Science and Technology Council, Taiwan (Grant No. MOST111-2923-B-039-001-MY3; MOST110-2923-B-039-001-MY3), and China Medical University, Taiwan (CMU110-S-03, CMU110-MF-61, CMU111-MF-96, and CMU109-S-09).