title: Structure-activity relationships of carbocyclic 6-benzylthioinosine analogues as subversive substrates of Toxoplasma gondii adenosine kinase.
abstract: Carbocyclic 6-benzylthioinosine analogues were synthesized and evaluated for their binding affinity against Toxoplasma gondii adenosine kinase [EC.2.7.1.20]. Various substituents on the aromatic ring of the 6-benzylthio group resulted in increased binding affinity to the enzyme as compared to the unsubstituted compound. Carbocyclic 6-(p-methylbenzylthio)inosine 9n exhibited the most potent binding affinity. Docking simulations were performed to position compound 9n into the T. gondii adenosine kinase active site to determine the probable binding mode. Experimental investigations and theoretical calculations further support that an oxygen atom of the sugar is not critical for the ligand-binding. In agreement with its binding affinity, carbocyclic 6-(p-methylbenzylthio)inosine 9n demonstrated significant anti-toxoplasma activity (IC(50)=11.9microM) in cell culture without any apparent host-toxicity.
authors.affiliation: Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA.
authors.forename: Young Ah
authors.initials: YA
authors.lastname: Kim
authors.forename: Ravindra K
authors.initials: RK
authors.lastname: Rawal
authors.forename: Jakyung
authors.initials: J
authors.lastname: Yoo
authors.forename: Ashoke
authors.initials: A
authors.lastname: Sharon
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Jha
authors.forename: Chung K
authors.initials: CK
authors.lastname: Chu
authors.forename: Reem H
authors.initials: RH
authors.lastname: Rais
authors.forename: Omar N
authors.initials: ON
authors.lastname: Al Safarjalani
authors.forename: Fardos N M
authors.initials: FN
authors.lastname: Naguib
authors.forename: Mahmoud H
authors.initials: MH
authors.lastname: El Kouni
mesh_terms: D000248:Adenosine Kinase / Q000037:antagonists & inhibitors*; D000818:Animals; D015195:Drug Design; D007288:Inosine / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D013868:Thioinosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D014122:Toxoplasma / Q000201:enzymology*
chemical_list: C485108:6-benzylthioinosine; D013868:Thioinosine; D007288:Inosine; D000248:Adenosine Kinase