Filak LK, Kalinowski DS, Bauer TJ, Richardson DR, Arion VB. Effect of the piperazine unit and metal-binding site position on the solubility and anti-proliferative activity of ruthenium(II)- and osmium(II)- arene complexes of isomeric indolo[3,2-c]quinoline-piperazine hybrids.
Inorg Chem 2014;
53:6934-43. [PMID:
24927493 PMCID:
PMC4087041 DOI:
10.1021/ic500825j]
[Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
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In this study, the indoloquinoline
backbone and piperazine were combined to prepare indoloquinoline–piperazine
hybrids and their ruthenium- and osmium-arene complexes in an effort
to generate novel antitumor agents with improved aqueous solubility.
In addition, the position of the metal-binding unit was varied, and
the effect of these structural alterations on the aqueous solubility
and antiproliferative activity of their ruthenium- and osmium-arene
complexes was studied. The indoloquinoline–piperazine hybrids
L1–3 were prepared in situ and
isolated as six ruthenium and osmium complexes [(η6-p-cymene)M(L1–3)Cl]Cl, where
L1 = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-2-N-amine, M = Ru ([1a]Cl), Os ([1b]Cl), L2 = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-4-N-amine, M = Ru ([2a]Cl), Os ([2b]Cl), L3 = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-8-N-amine, M = Ru ([3a]Cl), Os ([3b]Cl). The
compounds were characterized by elemental analysis, one- and two-dimensional
NMR spectroscopy, ESI mass spectrometry, IR and UV–vis spectroscopy,
and single-crystal X-ray diffraction. The antiproliferative activity
of the isomeric ruthenium and osmium complexes [1a,b]Cl–[3a,b]Cl was examined in
vitro and showed the importance of the position of the metal-binding
site for their cytotoxicity. Those complexes containing the metal-binding
site located at the position 4 of the indoloquinoline scaffold ([2a]Cl and [2b]Cl) demonstrated the most potent
antiproliferative activity. The results provide important insight
into the structure–activity relationships of ruthenium- and
osmium-arene complexes with indoloquinoline–piperazine hybrid
ligands. These studies can be further utilized for the design and
development of more potent chemotherapeutic agents.
Three different structural isomers of the indoloquinoline−piperazine
hybrid were prepared in situ and isolated as ruthenium-
and osmium-arene complexes. The effect of the piperazine unit and
metal-binding site position on the aqueous solubility and antiproliferative
activity of the metal complexes was studied.
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