The present invention relates to novel compounds of the general formula (I), their derivatives, analogs, tautomeric forms, stereoisomers, polymorphs, hydrates, solvates, pharmaceutically acceptable salts and compositions, metabolites and prodrugs thereof. The present invention more particularly provides novel cephalosporin antibiotics of the general formula (I). Also included is a method for treatment of infectious diseases in a mammal comprising administering an effective amount of a compound of formula (I) as described above.