Fusidic acid derivatives

Abstract

The invention relates to a new series of fusidic acid derivatives, to salts and easily hydrolyzable esters thereof, to the preparation of these compounds and to pharmaceutical compositions containing the compounds, the new compounds having the general formula: ##STR1## in which Q.sub.1 and Q.sub.2 stand for the group ##STR2## or oxygen, A represents oxygen or sulphur, and R.sub.1 stands for a straight or branched alkyl radical having from 1 to 12 carbon atoms, R.sub.1 can further be an alkenyl or alkynyl radical having from 3 to 6 carbon atoms, a cycloalkyl radical having from 3 to 7 carbon atoms in the alicyclic ring, an aralkyl or aryl radical, R.sub.1 can also be a heterocyclic radical having 5 or 6 ring atoms and containing oxygen, sulphur and/or nitrogen atoms, R.sub.1 optionally being further substituted, and in which formula I the dotted line between C-24 and C-25 indicates that the carbon atoms in question are connected by either a double bond or a single bond, and the asterix at C-20 indicates that the compounds exist in two diastereomeric forms, and thus the invention comprises the pure diastereomers as well as mixtures of these. The compounds of the present invention possess antibacterial properties and show further interesting antimicrobial and pharmacokinetic properties.