Novel fusidic acid derivatives

A compound of general formula I

• wherein X represents halogen, trifluoromethyl, cyano, azido, alkyl, alkenyl or aryl, wherein said alkyl, alkenyl or aryl are optionally substituted by one or more, same or different substituents selected from the group consisting of alkyl, alkenyl, aryl, alkoxy, nitro, alkylthio, halogen, azido, trifluoromethyl and cyano;
• Y and Z both represent hydrogen, or together with the C-17/C-20 bond form a double bond between C-17 and C-20, or together are methylene and form a cyclopropane ring in combination with C-17 and C-20;
• A represents a bond, O, S or S(O);
• B represents C1-6 alkyl, C2-6 alkenyl, C1-6 acyl, C3-7 cycloalkylcarbonyl or benzoyl, all of which are optionally substituted with one or more substituents selected from the group consisting of halogen, hydroxy, alkoxy, aryl, heteroaryl and azido, or, if A represents a bond, B may also represent hydrogen;
• Q1 and Q2 independently represent —CH2—, —C(O)—, —(CHOH)—, —(CHOR)—, —(CHSH)—, —(NH)—, —(CHNH2)— or —(CHW)—, wherein R represents C1-6 alkyl and W represents halogen, cyano, azido or trifluoromethyl;
• Q3 represents —CH2—, —C(O)— or —CHOH—;
• G represents hydrogen, OH or O—CO—CH3;
• two bonds in the pentacyclic ring being depicted with full and dotted lines to indicate that either of the two bonds may be a double bond, in which case Y is absent and Z represents hydrogen;
• the bond between C-1 and C-2 being either a single or a double bond;
• and pharmaceutically acceptable salts and easily hydrolysable esters thereof.