Effect of papulacandin B on glucan synthesis in Paracoccidioides brasiliensis.

Papulacandin B, an inhibitor of beta-glucan synthesis in some fungi, was tested on both morphological phases of Paracoccidioides brasiliensis. In vivo, the antibiotic did not affect yeast morphology or growth but it inhibited mycelial growth and yeast----mycelium transformation. Increase of alpha-glucan and decrease of beta-glucan synthesis was also observed in the fungal cell wall of the mycelial form after addition of papulacandin B. Synthesis in vitro of beta-glucan was partially substituted by the synthesis of an amylase-sensitive glucan.