127785-64-2

Antifungal.

ChEBI: A cyclodepsipeptide antibiotic, which is isolated from the filamentous fungus Aureobasidium pullulans R106 and is toxic to yeast at low concentrations (0.1-0.5 ug/ml).

Aureobasidin A is a cyclic depsipeptide that is produced byfermentation in cultures of Aureobasidium pullulan.Aureobasidin A acts as a tight-binding noncompetitive inhibitorof the enzyme inositol phosphorylceramide synthase(IPC synthase), which is an essential enzyme for fungalsphingolipid biosynthesis. A unique structural feature of theaureobasidins is the N-methylation of four of seven amide nitrogenatoms. The lack of tautomerism dictated by N-methylationmay contribute to forming a stable solution conformerthat is shaped somewhat like an arrowhead, the presumed biologicallyactive conformation of aureobasidin-A.The pradimycins and benanomycins are naphthacenequinonesthat bind mannan in the presence of Ca²⁺ to disrupt the cell membrane in pathogenic fungi. Both demonstrate good in vitro and in vivo activity againstCandida spp. and C. neoformans clinical isolates.

This cyclic depsipeptide antibiotic (FWAureosasidin-A = 1101.43; CAS 127785- 64-2) from Aureobasidium pullulans R106 is toxic (typically at 0.1-0.5 μg/mL) against Saccharomyces cerevisiae, Schizosaccharo-myces pombe, Candida glabrata, Aspergillus nidulans, and A. niger. Aureobasdin A inhibits inositolphosphoryl-ceramide synthase. Note that the antibiotic contains N-methyl-L-valine, L-alloisoleucine, N-methyl-L-phenyl-alanine, and N-methyl-3-hydroxy-L-valine. Target (s) : inositolphosphoryl- ceramide synthase, or ceramide inositolphosphoryltransferase, inhibited by aureobasidin A.