Antiviral activity of glycyrrhizic acid conjugates with amino acid esters against Zika virus

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

“…The GL derivatives used in this study may be divided into three groups: Compounds 2 – 8 are GL conjugates containing two L- or D-amino acids methyl esters; group II (Compounds 9 – 16 ) is presented by GL conjugates containing two residues of ethyl esters L- or D-amino acids, and dipeptide Gly-PheOEt; group III includes GL conjugates with free L-amino acids 17 – 21. Compounds 2 [ 42 ] , 3 [ 43 ] , 5 [ 42 ] , 6 [ 42 , 46 ] , 8 [ 47 ] , 9 [ 46 ], 11 [ 46 ], 16 [ 46 ] , 17 – 20 [ 46 , 48 , 49 ] , and 21 [ 46 , 50 ] were previously described and their analytical and spectral data were identical to the published data. Conjugates 2 – 5 with methyl esters of amino acids were produced using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) [ 48 ] in dimethylformamide (DMF) in the presence of an excess of triethyl amine at room temperature (20–22 °C), showing yields of 52–55% after purification by column chromatography (CC).…”

“…Conjugates 2 – 5 with methyl esters of amino acids were produced using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) [ 48 ] in dimethylformamide (DMF) in the presence of an excess of triethyl amine at room temperature (20–22 °C), showing yields of 52–55% after purification by column chromatography (CC). Compounds 6 – 16 were prepared by the selective activation of COOH groups of the GL glucuronide part with HOSu/DCC [ 46 , 49 , 51 ] in DMF with yields of 55–60%. GL conjugates with free amino acids 17 – 21 were synthesized by a new simplified procedure using amino acids as Na salts in a mixture of 1N aqueous NaOH and DMF with yields of 54–56% after the purification by CC.…”

“…All compounds produced had a purity of ≥95% according to HPLC analysis ( Supplementary Figures S1–S20 ). Analytical and spectral data for GL derivatives 2 [ 42 ] , 3 [ 43 ] , 5 [ 42 ] , 6 [ 42 , 46 ] , 8 [ 47 ] , 9 [ 46 ], 11 [ 46 ], 16 [ 46 ] , 17 – 20 [ 46 , 48 , 49 ] , and 21 [ 46 , 50 ] were identical to the previously published data but their 1 H NMR spectra (500 MHz) are given firstly in this paper. The structures of the novel Compounds 4, 7, 10, 12 – 14, and 15 were confirmed by IR and NMR ( 1 H-500 MHz and 13 C-125 MHz) spectra and elemental analysis.…”

“…GL inhibits several pathogenic flaviviruses such as yellow fever virus and DENV at high non-toxic concentrations [ 44 ]. Recently, we reported that GL and some of its derivatives had high antiviral activity against DENV2 [ 45 ] and ZIKV [ 46 ]. The antiviral activity of GL and its derivatives is associated mainly with the ability to potentiate ϒ-interferon production in vitro and in vivo [ 31 , 32 , 33 ].…”

Azepanodipterocarpol is potential candidate for inhibits influenza H1N1 type among other lupane, oleanane, and dammarane A-ring amino-triterpenoids

“…The antiviral activity of this class of compounds also has a fairly wide spectrum. Triterpenes are active against viruses such as human immunodeficiency viruses, hepatitis B and C, various types of influenza viruses, acute respiratory viral infections, herpes viruses, human enterovirus, Epstein-Barr, and Zika viruses [15,16]. The potential of triterpenoids as antiviral platforms is very promising.…”