Echinocandin B Explained

Echinocandin B, a lipopeptide, is a naturally occurring cyclic hexapeptide with a linoleoyl side chain. It belongs to a class of antifungal agents called echinocandins, which inhibits the synthesis of glucan, a major component of the fungal cell wall, via noncompetitive inhibition of a crucial enzyme, β-(1→3)-D-glucan synthase. Echinocandin B is a fermentation product of Aspergillus nidulans and the closely related species, A. rugulosus;^[1] discovered in 1974 in A. nidulans var. echinulatus strain A 32204 in Germany,^[2] it was the first of the echinocandin class of antifungals.

Echinocandin B can undergo deacylation (removal of the lipid side chain) by the action of a deacylase enzyme from the filamentous bacterium Actinoplanes utahensis, which catalyzes the cleavage of the linoleoyl side chain;^[3] in three subsequent synthetic steps, including a chemical reacylation, the antifungal drug anidulafungin is synthesized.^[4]

Notes and References

1. Denning DW . Echinocandins and pneumocandins - a new antifungal class with a novel mode of action . J Antimicrob Chemother . 1997 . 40 . 611–614 . 10.1093/jac/dkf045 . 9421307 . 5. free .
2. Nyfeler R, Keller-Schierlein W . Metabolites of microorganisms. 143. Echinocandin B, a novel polypeptide-antibiotic from Aspergillus nidulans var. echinulatus: isolation and structural components . Helv Chim Acta . 57 . 8 . 2459–2477 . 1974 . 4613708 . 10.1002/hlca.19740570818 .
3. Lei Shao . Jian Li . Aijuan Liu . Qing Chang . Huimin Lin . Daijie Chen . Efficient Bioconversion of Echinocandin B to Its Nucleus by Overexpression of Deacylase Genes in Different Host Strains . Applied and Environmental Microbiology . 79 . 4 . 1126–1133 . 2013 . 23220968 . 10.1128/AEM.02792-12 . 3568618. 2013ApEnM..79.1126S .
4. Web site: Anidulafungin EMA Europa. 2018-06-19. https://web.archive.org/web/20180619094148/http://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Scientific_Discussion/human/000788/WC500020676.pdf. dead.