Sordarin is an inhibitor of fungal protein synthesis originally isolated from S. araneosa.[1] It binds to elongation factor 2 (EF-2) in the presence of ribosomes and inhibits the uncoupled GTPase activity of equimolar mixtures of EF-2 and ribosomes from C. albicans (IC50 = 0.1 μM). Sordarin inhibits protein synthesis in cell-free lysates of C. albicans, C. glabrata, and C. neoformans (IC50s = 0.01, 0.2, and 0.06 μg/ml, respectively) but not in rabbit reticulocytes (IC50 = >100 μg/ml).[1] [2] It inhibits the growth of C. albicans (MIC = 8 μg/ml) but not C. glabrata or C. neoformans (MICs = >125 μg/ml).
Reference:
[1]. Domínguez, J.M., Gómez-Lorenzo, M.G., and Martín, J.J. Sordarin inhibits fungal protein synthesis by blocking translocation differently to fusidic acid. J. Biol. Chem. 274(32), 22423-22427 (1999).
[2]. Domínguez, J.M., Kelly, V.A., Kinsman, O.S., et al. Sordarins: A new class of antifungals with selective inhibition of the protein synthesis elongation cycle in yeasts. Antimicrob. Agents Chemother. 42(9), 2274-2278 (1998).