Structure-activity relationships of 3-O-β-chacotriosyl oleanane-type triterpenoids as potential H5N1 entry inhibitors

Asprellcosides B of Ilex asprella Inhibits Influenza A Virus Infection by Blocking the Hemagglutinin- Mediated Membrane Fusion

“…The docking areas were within 3 Å from the crystallization of the ligand and the 90-Helex, 130-Loop, 220-Loop sites (PD ID: 1RVX). Prediction of the binding site of Asprellcosides B and HA2 by Autoligand was performed (Russell et al, 2008; Song et al, 2016), and the terminal binding site was confirmed by molecular docking (PDB ID: 1RU7, 3EYM). Docking results were analyzed with AutoDockTools.…”

“…Previous studies found that its main components include triterpenoid saponins, phenolic acids, and alkaloids (Huang et al, 2012; Lei et al, 2014). Several recent studies demonstrated the anti-influenza activity of triterpenoid saponin (Li et al, 2007; Song et al, 2016; Gong et al, 2017). The antiviral activity of Ilex asprella extracts was also demonstrated in an animal model of influenza A virus infection (Peng et al, 2016).…”

Development of anti‐influenza agents from natural products

“…SAR analysis suggested that either the introduction of a disubstituted amide structure at the 17-COOH of ursolic acid or alteration of the C-3 configuration of ursolic acid from the 3β-to 3α-form helped to significantly improve the selective index while retaining the antiviral activities. [75][76][77] Glycyrrhizic acid (GL, 66) and its aglycone glycyrrhetic acid (GLA), the principal triterpene glycosides from the displayed moderate inhibitory activity against the above-mentioned strains; 74 was somewhat better than 77. In addition, docking studies suggest that these compounds occupy the conserved pocket for sialic acid receptor, consistent with the SAR data.…”

Recent progress in the antiviral activity and mechanism study of pentacyclic triterpenoids and their derivatives

“…114 Recently, uralsaponin M (40), a novel triterpenoid saponin isolated from the roots of G. uralensis, was shown to exhibit inhibitory activity against the influenza virus A/WSN/33 (H1N1) in Madin-Darby canine kidney (MDCK) cells with an IC 50 value of 48.0 M. 115 Song et al reported that the conjugates of PTs with chacotriose could inhibit the entry of highly pathogenic H5N1 influenza A virus into MDCK cells in varying degrees. [116][117][118][119] Compound 41, a 3-O--chacotriosyl substituted methyl ursolate derivative, showed potent anti-influenza A (H5N1) virus entry activity with IC 50 at 6.00-8.54 M. 119 In another work, both the chacotriosyl and the aglycone moiety have been reported to have an important effect on the activity against influenza virus and the anti-influenza activity could be improved when the disubstituted amide was introduced to the C17-COOH position. 120 The introduction of dimethylamine at the C17-COOH provides the compound 42, which showed the most potent anti-influenza activity (IC 50 In view of the broad antiviral spectrum of PTs, [85][86][87]89 our group established an anti-influenza virus drug screening model and screened a mini-library of PT-glycoconjugates.…”

“…Song et al. reported that the conjugates of PTs with chacotriose could inhibit the entry of highly pathogenic H5N1 influenza A virus into MDCK cells in varying degrees . Compound 41 , a 3‐ O ‐ β ‐chacotriosyl substituted methyl ursolate derivative, showed potent anti‐influenza A (H5N1) virus entry activity with IC 50 at 6.00–8.54 μM .…”