Echinocandins, such as caspofungin, function by preventing the synthesis of which component of fungal cell walls?

Echinocandins, including caspofungin, target the synthesis of glucans, which are essential components of the fungal cell wall. These compounds are polysaccharides that help provide structural integrity and rigidity to the cell wall of fungi. By inhibiting the enzyme responsible for glucan synthesis, echinocandins effectively weaken the cell wall, leading to cell lysis and ultimately the death of the fungal cells. This mechanism makes echinocandins particularly effective against certain types of fungi, including Candida and Aspergillus species.

In contrast, phospholipids are vital components of cell membranes, not cell walls, and do not relate to glucan synthesis. Starch and glycogen are storage carbohydrates in fungi but do not play a structural role in the cell wall. Therefore, the prevention of glucan synthesis is specifically what makes echinocandins effective antifungal agents.