title: Pentacyclic triterpenes grafted on CD cores to interfere with influenza virus entry: A dramatic multivalent effect.
abstract: Multivalent effect plays an important role in biological processes, particularly in the specific recognition of virus with its host cell during the first step of infection. Here we report the synthesis of multivalent pentacyclic triterpene grafted on cyclodextrin core and potency of against influenza entry activity. Nine star-shaped compounds containing six, seven and eight pentacyclic triterpene pharmacophore on cyclodextrin scaffold were prepared by way of copper-catalyzed azide-alkyl cycloaddition reaction under microwave activation. Some of the multimers exhibited much potent antiviral activity against H1N1 virus (A/WSN/33), even equivalent or superior to oseltamivir. The most active compound 31, a heptavalent oleanolic acid-β-cyclodextrin conjugate, shows an up to 125-fold potency enhancement by its IC50 value over the corresponding monovalent conjugate and oleanolic acid, disclosing a clear multivalent effect. Further studies show that three compounds 31-33 exhibited broad spectrum inhibitory activity against other two human influenza A/JX/312 (H3N2) and A/HN/1222 (H3N2) viruses with the IC50 values at 2.47-14.90 μM. Most importantly, we found that compound 31, one of the best representative conjugate, binds tightly to the viral envelope hemagglutinin with a dissociation constant of KD = 2.08 μM, disrupting the interaction of hemagglutinin with the sialic acid receptor and thus the attachment of viruses to host cells. Our study might establish a strategy for the design of new pharmaceutical agents based on multivalency so as to block influenza virus entry into host cells.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China. Electronic address: slxiao@bjmu.edu.cn.
authors.forename: Sulong
authors.initials: S
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Longlong
authors.initials: L
authors.lastname: Si
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Pingxuan
authors.initials: P
authors.lastname: Jiao
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Zibo
authors.initials: Z
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Xiaoshu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Han
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Renyang
authors.initials: R
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Han
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Fu
authors.affiliation: Institut Parisien de Chimie Moléculaire, CNRS UMR 8232, Université Pierre & Marie Curie-Paris 6, 4 place Jussieu, 75005 Paris, France.
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Lihe
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China. Electronic address: deminzhou@bjmu.edu.cn.
authors.forename: Demin
authors.initials: D
authors.lastname: Zhou
mesh_terms: D000818:Animals; D004285:Dogs; D053118:Influenza A Virus, H1N1 Subtype / Q000502:physiology*; D061985:Madin Darby Canine Kidney Cells; D008561:Membrane Fusion; D014315:Triterpenes / Q000737:chemistry*
chemical_list: D014315:Triterpenes
keywords: Entry inhibitor; Hemagglutinin; Influenza virus; Multivalent effect; Pentacyclic triterpene