Fritz Hansske

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 2,10,10-trimethal-4-oxo-tricyclo[7.2.0.02.5]undec-6-en-carbaldehyde (with the relative stereo chemistry IS, 2R, 5R, 9R) (1). The inhibitor, which was named collybial, is structurally related to koraiol, a sesquiterpenoid isolated from Pinus koraiensis (Khan V. A. (1979), Khim. Prir. Soedin 5, 652-658). Collybial inhibited the growth of Gram-positive bacteria at concentrations starting from 21.5 μm . The propagation of vesicular stomatitis virus (VSV) in baby hamster kidney (BHK-21) cells was inhibited by 21.5 μm collybial. Cytotoxic effects on BHK cells were observed at 5 fold higher concentrations.

Two Inhibitors of Platelet Aggregation from a Panus Species (Basidiomycetes)

Two inhibitors of platelet aggregation were isolated from fermentations of Panus sp. 9096. One inhibitor proved to be identical to naematolon (2), an antibiotic previously isolated by S. Backens et al. from several Hypholoma species. The other metabolite, panudial (1), is a new nordrimane (cis-annelation of the bicyclus) lacking the carbon atom in position 10 of the drimane skeleton. Panudial is a potent inhibitor of bovine and human platelet aggregation stimulated by different inducers.

14-epidihydrocochlioquinone B and 14-epicochlioquinone B, antibiotics from fermentations of the ascomycete Neobulgaria pura: structure elucidation and effects on platelet aggregation

Abstract 14-Epicochlioquinone B (1) and 14-epidihydrocochlioquinone B (2) were isolated from sub merged cultures of Neobulgaria pura (Pers. ex Fr.) Petrak. 14-Epicochlioquinone B is a potent inhibitor of hum an and bovine platelet aggregation stimulated by different inducers. 14-Epidihydrocochlioquinone B does not inhibit the aggregation of platelets. In addition, both 1 and 2 exhibited cytotoxic and antimicrobial activites.