title: Structure-activity relationships of antitubercular salicylanilides consistent with disruption of the proton gradient via proton shuttling.
abstract: A series of salicylanilides was synthesized based on a high-throughput screening hit against Mycobacterium tuberculosis. A free phenolic hydroxyl on the salicylic acid moeity is required for activity, and the structure-activity relationship of the aniline ring is largely driven by the presence of electron withdrawing groups. We synthesized 94 analogs exploring substitutions of both rings and the linker region in this series and we have identified multiple compounds with low micromolar potency. Unfortunately, cytotoxicity in a murine macrophage cell line trends with antimicrobial activity, suggesting a similar mechanism of action. We propose that salicylanilides function as proton shuttles that kill cells by destroying the cellular proton gradient, limiting their utility as potential therapeutics.
authors.affiliation: Pharmacology Research Center, Korea Research Institute of Chemical Technology, Jang-Dong100, Yuseong-Gu, Daejeon 305-600, Republic of Korea.
authors.forename: Ill-Young
authors.initials: IY
authors.lastname: Lee
authors.forename: Todd D
authors.initials: TD
authors.lastname: Gruber
authors.forename: Amanda
authors.initials: A
authors.lastname: Samuels
authors.forename: Minhan
authors.initials: M
authors.lastname: Yun
authors.forename: Bora
authors.initials: B
authors.lastname: Nam
authors.forename: Minseo
authors.initials: M
authors.lastname: Kang
authors.forename: Kathryn
authors.initials: K
authors.lastname: Crowley
authors.forename: Benjamin
authors.initials: B
authors.lastname: Winterroth
authors.forename: Helena I
authors.initials: HI
authors.lastname: Boshoff
authors.forename: Clifton E
authors.initials: CE
authors.lastname: Barry
mesh_terms: D000818:Animals; D000995:Antitubercular Agents / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D002460:Cell Line; D006801:Humans; D008264:Macrophages / Q000187:drug effects / Q000382:microbiology; D051379:Mice; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D011522:Protons; D012458:Salicylanilides / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D013329:Structure-Activity Relationship; D014376:Tuberculosis / Q000188:drug therapy
chemical_list: D000995:Antitubercular Agents; D011522:Protons; D012458:Salicylanilides