Studies on the inhibition of Bacillus subtilis growth by cordycepin

Abstract

1. 1. This work was undertaken to determine the specific enzymatic site at which cordycepin inhibits the growth of Bacillus subtilis. Of a number of compounds tested, the nucleosides of adenine and guanine were most effective in reversing this inhibition. This fact, coupled with the failure to demonstrate the accumulation of ultraviolet-absorbing intermediates in the acid-soluble fraction of these cells, as well as the ability of 5-amino-4-imidazolecarboxamide to partially reverse the inhibition of growth, suggests that cordycepin exerts its growth inhibitory effect in this organism on reactions in the synthesis of purines de novo.2. 2. Bacillus subtilis is capable of cleaving cordycepin to adenine and cordycepose. The fact that adenine can reverse cordycepin inhibition probably best explains the ability of this organism to overcome the inhibition at low concentrations.3. 3. Replacement of the 6-amino group of cordycepin by a hydroxyl group produced the hypoxanthine analog of cordycepin which was much less effective as an inhibitor.