Cyathin, a new antibiotic complex produced by Cyathus helenae

Abstract

The fungus Cyathus helenae Brodie (Gasteromycetes) produces a complex of antibiotic substances collectively called cyathin. Highest yields were obtained when the fungus was grown at room temperature for 25 days on a chemically defined liquid medium in static culture. The action spectrum of cyathin (and its components) was determined by placing cyathin-bearing paper discs on agar plates seeded with the microorganisms being tested. The cyathin complex is active against actinomycetes, bacteria (gram-positive as well as gram-negative), and some fungi, including dermatophytes. Weaker antimicrobial activity is also shown by C. striatus (Huds.) Willd. ex Pers., C. poeppigii L., and C. limbatus L. Seven different compounds have been isolated from the cyathin complex: 2,4,5-trihydroxybenzaldehyde (C7H6O4),cyathin A3(C20H30O3), cyathin A4(C20H30O4),allocyathinA4(C20H30O4),cyathin B3(C20H28O3), cyathin B4(C20H28O4), and cyathin C5(C20H26O5). Aside from 2,4,5-trihydroxybenzaldehyde, these compounds appear not to have been previously described. A discussion of some of the structural features of cyathin A4 and cyathin A3 is presented