Synthesis and anti-influenza evaluation of polyvalent sialidase inhibitors bearing 4-guanidino-Neu5Ac2en derivatives.

We synthesized polyvalent sialidase inhibitors bearing 4-guanidino-Neu5Ac2en analogues on the polyglutamic acid back bone, via a spacer of alkyl ether at the C-7 position. These multivalent conjugates 9 and 10 showed enhancement of antiviral activity against infuenza A virus and more potent efficacy in vivo relative to a monomeric sialidase inhibitor.