Abstract: The invention features compounds of the formula: or a pharmaceutically acceptable salt thereof, wherein A is CR2 and B is N; wherein n is 0-3; wherein R1 is (CH2)m—{(G)o—(CH2)p}q—L, in which G is CH2, CH?CH, C?C, CO, O, S, or NR5, where R5 is H or C1-6 alkyl, CHR6, where R6 is OH or C1-6 alkyl, CH(CR7R8), where each of R7 and R8 is, independently, H, halo, or C1-6 alkyl, OCO, CONR9, NR10CO, where each of R9 and R10 is, independently, H or C1-6 alkyl, SO2NH, or NHSO2; in which m is 1-4, o is 0-4, p is 0-4, and q is 0-4. The compounds disclosed herein have potent anti-microbial, e.g., both Gram-positive and Gram-negative anti-bacterial properties. The compounds inhibit DNA polymerase IIIC and DNA polymerase IIIE enzymes and thus act therapeutically by inhibiting the growth of a broad array of bacteria. The compounds can be administered to prevent or to treat Gram-positive or Gram-negative bacterial infections, e.g., in eukaryotic cell cultures, animals, or humans.