title: Antitrypanosomal, antileishmanial, and antimalarial activities of quaternary arylalkylammonium 2-amino-4-chlorophenyl phenyl sulfides, a new class of trypanothione reductase inhibitor, and of N-acyl derivatives of 2-amino-4-chlorophenyl phenyl sulfide.
abstract: Quaternization of the nitrogen atom of 2-amino-4-chlorophenyl phenyl sulfide analogues of chlorpromazine improved inhibition approximately 40-fold (3',4'-dichlorobenzyl-[5-chloro-2-phenylsulfanyl-phenylamino)-propyl]-dimethylammonium chloride inhibited trypanothione reductase from Trypanosoma cruzi with a linear competitive Ki value of 1.7 +/- 0.2 microM). Molecular modelling explained docking orientations and energies by: (i) involvement of the Z-site hydrophobic pocket (roughly bounded by F396', P398', and L399'), (ii) ionic interactions for the cationic nitrogen with Glu-466' or -467'. A series of N-acyl-2-amino-4-chlorophenyl sulfides showed mixed inhibition (Ki, Ki' = 11.3-42.8 microM). The quaternized analogues of the 2-chlorophenyl phenyl sulfides had strong antitrypanosomal and antileishmanial activity in vitro against T. brucei rhodesiense STIB900, T. cruzi Tulahuan, and Leishmania donovani HU3. The N-acyl-2-amino-4-chlorophenyl sulfides were active against Plasmodium falciparum. The phenothiazine and diaryl sulfide quaternary compounds were also powerful antimalarials, providing a new structural framework for antimalarial design.
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Seheli
authors.initials: S
authors.lastname: Parveen
authors.forename: Mohammed O F
authors.initials: MO
authors.lastname: Khan
authors.forename: Susan E
authors.initials: SE
authors.lastname: Austin
authors.forename: Simon L
authors.initials: SL
authors.lastname: Croft
authors.forename: Vanessa
authors.initials: V
authors.lastname: Yardley
authors.forename: Peter
authors.initials: P
authors.lastname: Rock
authors.forename: Kenneth T
authors.initials: KT
authors.lastname: Douglas
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001555:Benzene Derivatives / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002746:Chlorpromazine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D007893:Leishmania donovani / Q000187:drug effects; D008958:Models, Molecular; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D010963:Plasmodium falciparum / Q000187:drug effects; D000644:Quaternary Ammonium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013440:Sulfides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D014344:Trypanocidal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D016833:Trypanosoma brucei rhodesiense / Q000187:drug effects; D014349:Trypanosoma cruzi / Q000187:drug effects
chemical_list: D000962:Antimalarials; D001555:Benzene Derivatives; D000644:Quaternary Ammonium Compounds; D013440:Sulfides; D014344:Trypanocidal Agents; D009247:NADH, NADPH Oxidoreductases; C049608:trypanothione reductase; D002746:Chlorpromazine