title: 6-Anilinouracil-based inhibitors of Bacillus subtilis DNA polymerase III: antipolymerase and antimicrobial structure-activity relationships based on substitution at uracil N3.
abstract: 6-Anilinouracils (6-AUs) are dGTP analogues which selectively inhibit the DNA polymerase III of Bacillus subtilis and other Gram-positive bacteria. To enhance the potential of the 6-AUs as antimicrobial agents, a structure-activity relationship was developed involving substitutions of the uracil N3 position in two 6-AU platforms: 6-(3,4-trimethyleneanilino)uracil (TMAU) and 6-(3-ethyl-4-methylanilino)uracil (EMAU). Series of N3-alkyl derivatives of both 6-AUs were synthesized and tested for their ability to inhibit purified B. subtilis DNA polymerase III and the growth of B. subtilis in culture. Alkyl groups ranging in size from ethyl to hexyl enhanced the capacity of both platforms to bind to the polymerase, and with the exception of hexyl, they also significantly enhanced their antimicrobial potency. N3 substitution of the EMAU platform with more hydrophilic hydroxyalkyl and methoxyalkyl groups marginally enhanced anti-polymerase III activity but enhanced antibacterial potency severalfold. In sum, the results of these studies indicate that the ring N3 of 6-anilinouracils can tolerate substituents of considerable size and structural variety and, thus, can be manipulated to significantly enhance the antibacterial potency of this novel class of polymerase III-specific inhibitors.
authors.affiliation: Department of Pharmacology and Molecular Toxicology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Tarantino
authors.forename: C
authors.initials: C
authors.lastname: Zhi
authors.forename: J J
authors.initials: JJ
authors.lastname: Gambino
authors.forename: G E
authors.initials: GE
authors.lastname: Wright
authors.forename: N C
authors.initials: NC
authors.lastname: Brown
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects / Q000201:enzymology*; D004258:DNA Polymerase III / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D013329:Structure-Activity Relationship; D014498:Uracil / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D014498:Uracil; C013400:6-aminouracil; D004258:DNA Polymerase III