Rationally improved isoniazid and ethionamide derivatives and activity through selective isotopic substitution

A compound according to the chemical structure:

• Where X is an oxygen or a sulfur atom selected from the group consisting of 16O, 17O, 18O, 32S, 33S and 34S;
• Y is a carbon atom selected from the group consisting of 12C and 13C;
• Z is a NH2 group or a NHNH2 group, which group is optionally isotopically labeled with at least one 15N atom;
• R is H or a C1-C3 alkyl group, with the proviso that R is H and Z is an optionally isotopically labeled NHNH2 group when X is an oxygen atom and R is a C1-C3 alkyl group, preferably an ethyl group and Z is an optionally isotopically labeled NH2 group when X is a sulfur atom;
• Wherein at least one of X, Y and Z is isotopically labeled, or
• a pharmaceutically acceptable salt thereof.