COLLYBIAL, A NEW ANTIBIOTIC SESQUITERPENOID FROM COLLYBIA CONFLUENS (BASIDIOMYCETES)

A new antibiotic was isolated from fermentations of an american strain of Collybia confluens. its structure was elucidated by spectroscopic methods as -oxo-tricyclo[7.2.0.0(2.5)]undec-6-en-carbaldehyde (with th e relative stereo chemistry 1S, 2R, 5R, 9R) (1). The inhibitor, which was named collybial, is structurally related to koraiol, a sesquiterpe noid isolated from Pinus koraiensis (Khan V. A. (1979), Khim. Prir. So edin 5, 652-658). Collybial inhibited the growth of Gram-positive bact eria at concentrations starting from 21.5 mu M. The propagation of ves icular stomatitis virus (VSV) in baby hamster kidney (BHK-21) cells wa s inhibited by 21.5 mu M collybial. Cytotoxic effects on BHK cells wer e observed at 5 fold higher concentrations.