What is the echinocandins mechanism of action?
Echinocandins inhibit fungal cell wall synthesis.
They inhibit the enzyme b(1,3)-glucan synthase which is responsible for the synthesis of (1,3)-b-D glucan (a polysaccharide in the cell wall). As a result, they inhibit the synthesis of (1,3)-b-D-glucan which is an important polysaccharide component of the fungal cell wall. This results in the rupture of the fungal cell wall and cell death.
In other words, echinocandins inhibit the enzyme that makes the polysaccharide. If the polysaccharide is not made, then there is a missing component of the fungal cell wall and the fungal cell will die.