title: Improved antiparasitic activity by incorporation of organosilane entities into half-sandwich ruthenium(II) and rhodium(III) thiosemicarbazone complexes.
abstract: A series of ferrocenyl- and aryl-functionalised organosilane thiosemicarbazone compounds was obtained via a nucleophilic substitution reaction with an amine-terminated organosilane. The thiosemicarbazone (TSC) ligands were further reacted with either a ruthenium dimer [(η(6-i)PrC6H4Me)Ru(μ-Cl)Cl]2 or a rhodium dimer [(Cp*)Rh(μ-Cl)Cl]2 to yield a series of cationic mono- and binuclear complexes. The thiosemicarbazone ligands, as well as their metal complexes, were characterised using NMR and IR spectroscopy, and mass spectrometry. The molecular structure of the binuclear ruthenium(ii) complex was determined by single-crystal X-ray diffraction analysis. The thiosemicarbazones and their complexes were evaluated for their in vitro antiplasmodial activities against the chloroquine-sensitive (NF54) and chloroquine-resistant (Dd2) Plasmodium falciparum strains, displaying activities in the low micromolar range. Selected compounds were screened for potential β-haematin inhibition activity, and it was found that two Rh(iii) complexes exhibited moderate to good inhibition. Furthermore, the compounds were screened for their antitrichomonal activities against the G3 Trichomonas vaginalis strain, revealing a higher percentage of growth inhibition for the ruthenium and rhodium complexes over their corresponding ligand.
authors.affiliation: Department of Chemistry, University of Cape Town, Rondebosch 7701, Cape Town, South Africa. Gregory.Smith@uct.ac.za.
authors.forename: Muneebah
authors.initials: M
authors.lastname: Adams
authors.forename: Carmen
authors.initials: C
authors.lastname: de Kock
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Smith
authors.forename: Kirkwood M
authors.initials: KM
authors.lastname: Land
authors.forename: Nicole
authors.initials: N
authors.lastname: Liu
authors.forename: Melissa
authors.initials: M
authors.lastname: Hopper
authors.forename: Allyson
authors.initials: A
authors.lastname: Hsiao
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Burgoyne
authors.forename: Tameryn
authors.initials: T
authors.lastname: Stringer
authors.forename: Mervin
authors.initials: M
authors.lastname: Meyer
authors.forename: Lubbe
authors.initials: L
authors.lastname: Wiesner
authors.forename: Kelly
authors.initials: K
authors.lastname: Chibale
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Smith
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D000977:Antiparasitic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D016466:CHO Cells; D002219:Carbamates / Q000737:chemistry; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D006420:Hemeproteins / Q000037:antagonists & inhibitors; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D010963:Plasmodium falciparum / Q000187:drug effects; D012238:Rhodium / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013882:Thiosemicarbazones / Q000737:chemistry*; D014246:Trichomonas vaginalis / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D000977:Antiparasitic Agents; D002219:Carbamates; D006420:Hemeproteins; D009942:Organometallic Compounds; D012821:Silanes; D013882:Thiosemicarbazones; C020753:hemozoin; D012428:Ruthenium; D012238:Rhodium