Sugars as Pharmaceuticals - The Sugar Code - page 475

Figure 28.4 Structures of carbohydrate - based inhibitors.
Figure 28.5 Sialic acid glycomimetics.
Figure 28.6 Structures of some anti - infl uenza drugs.
of hemagglutinin to glycoconjugates terminating in sialic acid initiates infection
in host cells. Sialic acid-functionalized multivalent conjugates have been synthe-
sized that are capable of blocking this virus-cell adhesion mechanism (see Chapter
4) [13]. Some sialic acid glycomimetics have shown 10 4 - fold greater potency in
inhibitory activity compared with the parent polymers that bear only sialic acid
residues (Figure 28.5 ) [14] .
Neuraminidase inhibitors are glycomimetic drugs that inhibit the cleavage of
sialic acid residues attached to cellular glycolipids and viral glycoproteins. Drugs
such as zanamivir and oseltamivir (Figure 28.6 and Figure 17.3) are able to bind
to the neuraminidase that protrudes from the surface of the infl uenza virus - this
action stops the virus from exiting the host cell, reducing the amount of virus that
is released to infect other cells, and thus halting the spread of the virus throughout
respiratory mucus. If treatment using zanamivir and oseltamivir is commenced