Publications by authors named "Claire A Tessier"

25 Publications

  • Page 1 of 1

Synthesis, characterization, in vitro SAR study, and preliminary in vivo toxicity evaluation of naphthylmethyl substituted bis-imidazolium salts.

Bioorg Med Chem 2021 Jan 28;30:115893. Epub 2020 Nov 28.

Department of Chemistry, The University of Akron, Akron, OH 44325-3601, USA. Electronic address:

A series of novel bis-imidazolium salts was synthesized, characterized, and evaluated in vitro against a panel of non-small cell lung cancer (NSCLC) cells. Two imidazolium cores were connected with alkyl chains of varying lengths to develop a structure activity relationship (SAR). Increasing the length of the connecting alkyl chain was shown to correlate to an increase in the anti-proliferative activity. The National Cancer Institute's NCI-60 human tumor cell line screen confirmed this trend. The compound containing a decyl linker chain, 10, was chosen for further in vivo toxicity studies with C578BL/6 mice. The compound was well tolerated by the mice and all of the animals survived and gained weight over the course of the study.
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http://dx.doi.org/10.1016/j.bmc.2020.115893DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7903221PMC
January 2021

Synthesis of highly selective lysosomal markers by coupling 2-(2'-hydroxyphenyl)benzothiazole (HBT) with benzothiazolium cyanine (Cy): the impact of substituents on selectivity and optical properties.

J Mater Chem B 2019 12 12;7(47):7502-7514. Epub 2019 Nov 12.

Department of Chemistry, University of Akron, Akron, Ohio 44325, USA. and Maurice Morton Institute of Polymer Science, University of Akron, Akron, Ohio 44325, USA.

HBT-Cy 1 has been previously reported as a highly selective fluorescent probe for lysosome visualization in live cells. To further investigate the role of the structural components of HBT-Cy in lysosome selectivity, cyanine based fluorescent probe series (2-5) have been synthesized in good yields by connecting benzothiazolium cyanine (Cy) with 2-hydroxyphenylbenzothiazole (HBT) via a meta phenylene ring. Probes 2-5 exhibited exceptional photophysical properties including bright red-emission (λ≈ 630-650 nm), a large Stokes shift (Δλ > 130 nm) and high fluorescence quantum yields (φ≈ 0.1-0.5). Probes 2, 3, and 5 exhibited exceptional selectivity towards cellular lysosomes in NHLF and MO3.13 cells. Our further study revealed that the phenyl benzothiazolium cyanine component (6) was the lysosome directing group in the HBT-Cy probe structure. The attachment of the hydroxyphenyl benzothiazole (HBT) component to the HBT-Cy probe structure has significantly improved its photophysical properties. Lysosome probes 2, 3 and 5 exhibited excellent biocompatibility, quick staining, bright red fluorescence, and wash-free application for live cell imaging. These probes further exhibited excellent characteristics for bioimaging experiments including a non-alkalinizing nature, high biocompatibility, high photostability and long-term imaging ability (>4 hours).
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http://dx.doi.org/10.1039/c9tb01672dDOI Listing
December 2019

Synthesis, characterization, in vitro SAR and in vivo evaluation of N,N'bisnaphthylmethyl 2-alkyl substituted imidazolium salts against NSCLC.

Bioorg Med Chem Lett 2017 02 16;27(4):764-775. Epub 2017 Jan 16.

Department of Chemistry, University of Akron, Akron, OH 44325, United States. Electronic address:

Alkyl- and N,N'-bisnaphthyl-substituted imidazolium salts were tested in vitro for their anti-cancer activity against four non-small cell lung cancer cell lines (NCI-H460, NCI-H1975, HCC827, A549). All compounds had potent anticancer activity with 2 having IC values in the nanomolar range for three of the four cell lines, a 17-fold increase in activity against NCI-H1975 cells when compared to cisplatin. Compounds 1-4 also showed high anti-cancer activity against nine NSCLC cell lines in the NCI-60 human tumor cell line screen. In vitro studies performed using the Annexin V and JC-1 assays suggested that NCI-H460 cells treated with 2 undergo an apoptotic cell death pathway and that mitochondria could be the cellular target of 2 with the mechanism of action possibly related to a disruption of the mitochondrial membrane potential. The water solubilities of 1-4 was over 4.4mg/mL using 2-hydroxypropyl-β-cyclodextrin as a chemical excipient, thereby providing sufficient solubility for systemic administration.
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http://dx.doi.org/10.1016/j.bmcl.2017.01.035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5575737PMC
February 2017

Synthesis, characterization, and in vitro SAR evaluation of N,N'-bis(arylmethyl)-C-alkyl substituted imidazolium salts.

Bioorg Med Chem Lett 2017 01 24;27(2):196-202. Epub 2016 Nov 24.

Department of Chemistry, University of Akron, Akron, OH 44325, United States. Electronic address:

A series of C-alkyl substituted N,N'-bis(arylmethyl)imidazolium salts were synthesized, characterized, and tested for their in vitro anti-cancer activity against multiple non-small cell lung cancer cell lines by our group and the National Cancer Institute's-60 human tumor cell line screen to establish a structure-activity relationship. Compounds are related to previously published N,N'-bis(arylmethyl)imidazolium salts but utilize the historical quinoline motif and anion effects to increase the aqueous solubility. Multiple derivatives displayed high anti-cancer activity with IC values in the nanomolar to low micromolar range against a panel of non-small cell lung cancer cell lines. Several of these derivatives have high aqueous solubilities with potent anti-proliferative properties and are ideal candidates for future in vivo xenograft studies and have high potential to progress into clinic use.
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http://dx.doi.org/10.1016/j.bmcl.2016.11.075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5204360PMC
January 2017

Synthesis, anti-proliferative activity, SAR study, and preliminary in vivo toxicity study of substituted N,N'-bis(arylmethyl)benzimidazolium salts against a panel of non-small cell lung cancer cell lines.

Bioorg Med Chem 2017 01 5;25(1):421-439. Epub 2016 Nov 5.

Department of Chemistry, The University of Akron, Akron, OH 44325-3601, USA. Electronic address:

A series of N,N'-bis(arylmethyl)benzimidazolium salts have been synthesized and evaluated for their in vitro anti-cancer activity against select non-small cell lung cancer cell lines to create a structure activity relationship profile. The results indicate that hydrophobic substituents on the salts increase the overall anti-proliferative activity. Our data confirms that naphthylmethyl substituents at the nitrogen atoms (N(N)) and highly lipophilic substituents at the carbon atoms (C and C(C)) can generate benzimidazolium salts with anti-proliferative activity that is comparable to that of cisplatin. The National Cancer Institute's Developmental Therapeutics Program tested 1, 3-5, 10, 11, 13-18, 20-25, and 28-30 in their 60 human tumor cell line screen. Results were supportive of data observed in our lab. Compounds with hydrophobic substituents have higher anti-cancer activity than compounds with hydrophilic substituents.
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http://dx.doi.org/10.1016/j.bmc.2016.11.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5164943PMC
January 2017

Group 13 Superacid Adducts of [PCl2N]3.

Inorg Chem 2016 Apr 14;55(7):3283-93. Epub 2016 Mar 14.

Department of Chemistry, The University of Akron , Akron, Ohio 44325-3601, United States.

Irrespective of the order of the addition of reagents, the reactions of [PCl2N]3 with MX3 (MX3 = AlCl3, AlBr3, GaCl3) in the presence of water or gaseous HX give the air- and light-sensitive superacid adducts [PCl2N]3·HMX4. The reactions are quantitative when HX is used. These reactions illustrate a Lewis acid/Brønsted acid dichotomy in which Lewis acid chemistry can become Brønsted acid chemistry in the presence of adventitious water or HX. The crystal structures of all three [PCl2N]3·HMX4 adducts show that protonation weakens the two P-N bonds that flank the protonated nitrogen atom. Variable-temperature NMR studies indicate that exchange in solution occurs in [PCl2N]3·HMX4, even at lower temperatures than those for [PCl2N]3·MX3. The fragility of [PCl2N]3·HMX4 at or near room temperature and in the presence of light suggests that such adducts are not involved directly as intermediates in the high-temperature ring-opening polymerization (ROP) of [PCl2N]3 to give [PCl2N]n. Attempts to catalyze or initiate the ROP of [PCl2N]3 with the addition of [PCl2N]3·HMX4 at room temperature or at 70 °C were not successful.
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http://dx.doi.org/10.1021/acs.inorgchem.5b02341DOI Listing
April 2016

Anti-tumor activity of lipophilic imidazolium salts on select NSCLC cell lines.

Med Chem Res 2015 Jul 13;24(7):2838-2861. Epub 2015 Feb 13.

Department of Chemistry, The University of Akron, Akron, OH 44325-3601, USA.

The anti-tumor activity of imidazolium salts is highly dependent upon the substituents on the nitrogen atoms of the imidazolium cation. We have synthesized and characterized a series of naphthalene-substituted imidazolium salts and tested them against a variety of non-smallcell lung cancer cell lines. Several of these complexes displayed anticancer activity comparable to cisplatin. These compounds induced apoptosis in the NCI-H460 cell line as determined by Annexin V staining, caspase-3, and PARP cleavage. These results strongly suggest that this class of compounds can serve as potent chemotherapeutic agents.
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http://dx.doi.org/10.1007/s00044-015-1330-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4593509PMC
July 2015

Structure and conformation of the medium-sized chlorophosphazene rings.

Inorg Chem 2014 Sep 11;53(17):8874-86. Epub 2014 Aug 11.

University of Akron , Department of Chemistry, Akron, Ohio 44325-3601, United States.

Medium-sized cyclic oligomeric phosphazenes [PCl2N]m (where m = 5-9) that were prepared from the reaction of PCl5 and NH4Cl in refluxing chlorobenzene have been isolated by a combination of sublimation/extraction and column chromatography from the predominant products [PCl2N]3 and [PCl2N]4. The medium-sized rings [PCl2N]m have been characterized by electrospray ionization-mass spectroscopy (ESI-MS), their (31)P chemical shifts have been reassigned, and their T1 relaxation times have been obtained. Crystallographic data has been recollected for [PCl2N]5, and the crystal structures of [PCl2N]6, and [PCl2N]8 are reported. Halogen-bonding interactions were observed in all the crystal structures of cyclic [PCl2N]m (m = 3-5, 6, 8). The crystal structures of [P(OPh)2N]7 and [P(OPh)2N]8, which are derivatives of the respective [PCl2N]m, are also reported. Comparisons of the intermolecular forces and torsion angles of [PCl2N]8 and [P(OPh)2N]8 with those of three other octameric rings are described. The comparisons show that chlorophosphazenes should not be considered prototypical, in terms of solid-state structure, because of the strong influence of halogen bonding.
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http://dx.doi.org/10.1021/ic500272bDOI Listing
September 2014

Synthesis, characterization, and antimicrobial activity of silver carbene complexes derived from 4,5,6,7-tetrachlorobenzimidazole against antibiotic resistant bacteria.

Dalton Trans 2012 Jun 8;41(21):6500-6. Epub 2012 Mar 8.

Center for Silver Therapeutics Research, Department of Chemistry, The University of Akron, Akron, OH 44325-3601, USA.

Silver N-heterocyclic carbene complexes have been shown to have great potential as antimicrobial agents, affecting a wide spectrum of both Gram-positive and Gram-negative bacteria. A new series of three silver carbene complexes (SCCs) based on 4,5,6,7-tetrachlorobenzimidazole has been synthesized, characterized, and tested against a panel of clinical strains of bacteria. The imidazolium salts and their precursors were characterized by elemental analysis, mass spectrometry, (1)H and (13)C NMR spectroscopy, and single crystal X-ray diffraction. The silver carbene complexes, SCC32, SCC33, and SCC34 were characterized by elemental analysis, (1)H and (13)C NMR spectroscopy, and single crystal X-ray diffraction. These complexes proved highly efficacious with minimum inhibitory concentrations (MICs) ranging from 0.25 to 6 μg mL(-1). Overall, the complexes were effective against highly resistant bacteria strains, such as methicillin-resistant Staphylococcus aureus (MRSA), weaponizable bacteria, such as Yersinia pestis, and pathogens found within the lungs of cystic fibrosis patients, such as Pseudomonas aeruginosa, Alcaligenes xylosoxidans, and Burkholderia gladioli. SCC33 and SCC34 also showed clinically relevant activity against a silver-resistant strain of Escherichia coli based on MIC testing.
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http://dx.doi.org/10.1039/c2dt00055eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3703457PMC
June 2012

Nanoparticle encapsulated silver carbene complexes and their antimicrobial and anticancer properties: a perspective.

Dalton Trans 2012 Jan 6;41(2):327-36. Epub 2011 Oct 6.

Center for Silver Therapeutics Research, Department of Chemistry, University of Akron, Akron, OH 44325, USA.

This perspective discusses the uses of silver for both antimicrobial and anticancer applications. It focuses on the synthesis of silver N-heterocyclic carbene complexes (SCCs) and their in vitro efficacy against a broad spectrum of bacteria, as well as their antitumor properties. Finally, different polymeric nanoparticles are discussed as delivery vehicles for the encapsulation of SCCs and other therapeutic agents for use in vivo.
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http://dx.doi.org/10.1039/c1dt11100kDOI Listing
January 2012

Group 13 Lewis acid adducts of [PCl2N]3.

Inorg Chem 2011 Sep 18;50(18):8937-45. Epub 2011 Aug 18.

Department of Chemistry, The University of Akron, Ohio 44325-3601, USA.

Phosphazene polymers are classically synthesized by the high-temperature, ring-opening polymerization (ROP) of [PCl(2)N](3) to give [PCl(2)N](n), followed by functionalization of [PCl(2)N](n) with different side groups. We investigated the interactions of [PCl(2)N](3) with Lewis acids because Lewis acids have been used to induce the high-temperature ROP of [PCl(2)N](3). The reactions of [PCl(2)N](3) with MX(3) (M = group 13, X = halides), under strict anaerobic conditions gave adducts [PCl(2)N](3)·MX(3). Adducts were characterized by X-ray crystallography and multinuclear and variable-temperature NMR studies, and mechanistic understanding of their fluxional behavior in solution was achieved. The properties of the [PCl(2)N](3)·MX(3) adducts at or near room temperature strongly suggests that such adducts are not involved directly as intermediates in the high-temperature ROP of [PCl(2)N](3).
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http://dx.doi.org/10.1021/ic201075zDOI Listing
September 2011

Synthesis and antimicrobial studies of silver N-heterocyclic carbene complexes bearing a methyl benzoate substituent.

Inorganica Chim Acta 2010 Dec;364(1):125-131

The University of Akron, Akron, OH 44325-3601.

Due to the properties of silver as an antimicrobial, our research group has synthesized many different silver carbene complexes. Two new silver N-heterocyclic carbene complexes derived from 4,5-dichloroimidazole and theobromine bearing methyl benzoate substituents were synthesized by in situ carbene formation using silver acetate as the base in the reaction. The new compounds were fully characterized by several methods including NMR spectroscopy and X-ray crystallography. Preliminary antimicrobial efficacy studies against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli were conducted. The results of this study demonstrated antimicrobial efficacy of the two complexes comparable to silver nitrate, showing their potential for use in the treatment of bacterial infections.
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http://dx.doi.org/10.1016/j.ica.2010.08.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3014616PMC
December 2010

The medicinal applications of imidazolium carbene-metal complexes.

Chem Rev 2009 Aug;109(8):3859-84

Department of Chemistry, The University of Akron, Akron, Ohio 44325-3601, USA.

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http://dx.doi.org/10.1021/cr800500uDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2763352PMC
August 2009

Synthesis, stability, and antimicrobial studies of electronically tuned silver acetate N-heterocyclic carbenes.

J Med Chem 2008 Mar 21;51(6):1577-83. Epub 2008 Feb 21.

Department of Chemistry, University of Akron, Akron, OH 44325-3601, USA.

A series of methylated imidazolium salts with varying substituents on the 4 and 5 positions of the imidazole ring were synthesized. These salts were reacted with silver acetate to afford their corresponding silver N-heterocyclic carbene (NHC) complexes. These complexes were then evaluated for their stability in water as well as for their antimicrobial efficacy against a variety of bacterial strains associated with cystic fibrosis and chronic lung infections.
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http://dx.doi.org/10.1021/jm0708679DOI Listing
March 2008

A crystallographically isolated dimeric hydrolyzed chloro-phosphazene dianion.

Acta Crystallogr Sect E Struct Rep Online 2008 Dec 20;65(Pt 1):m105. Epub 2008 Dec 20.

The University of Akron, Chemistry Department, Akron, OH 44325-3601, USA.

Single crystals of the title compound bis[bis-(1-ethyl-3-methyl-imidazol-2-yl-idene)silver(I)] 1,5,5,7,11,11-hexa-chloro-2,8-di-oxa-4,6,10,12,13,14-hexa-aza-1λ(5),3,5λ(5),7λ(5),9,11λ(5)-hexa-phospha-tricyclo-[7.3.1.1(3,7)]tetra-deca-1(13),4,7(14),10-tetra-ene-6,12-diide 3,9-dioxide, [Ag(C(6)H(10)N(2))(2)](Cl(6)N(6)O(4)P(6))(0.5), were isolated from the reaction of the silver N-heteocyclic carbene complex [Ag(C(6)H(10)N(2))(2)]Cl and hexa-chloro-cyclo-triphos-phazene [NPCl(2)](3 )in the presence of water. The asymmetric unit contains one silver carbene cation with the carbene ligands bound to the Ag(I) in an almost linear arrangement and one half of a hydrolyzed phosphazene dianion. The second cation and additional half of the anion are generated by an inversion center.
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http://dx.doi.org/10.1107/S1600536808042116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2968009PMC
December 2008

Ovarian cancer activity of cyclic amine and thiaether metal complexes.

J Med Chem 2007 Apr 8;50(7):1703-6. Epub 2007 Mar 8.

The University of Akron, 190 East Buchtel Commons, Akron, Ohio 44325, USA.

A thiaether metal complex 1-aza-4,7-dithiacyclononane-RhCl3, 2, and cyclic amine metal complexes tacn-CuBr2, 3, and Me3tacn-RuCl3, 4, have been evaluated for anticancer activity against the ovarian cancer cell line NuTu-19 and for cell toxicity against the noncancerous ovarian tissue cell line OVepi. Specifically, metal complex 2 is active when compared to cisplatin at micromolar concentrations using the MTT and cell invasion assay. The in vitro results reported warrant further evaluation of metal complex 2 in living systems.
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http://dx.doi.org/10.1021/jm060857sDOI Listing
April 2007

Synthesis from caffeine of a mixed N-heterocyclic carbene-silver acetate complex active against resistant respiratory pathogens.

J Med Chem 2006 Nov;49(23):6811-8

Department of Chemistry, University of Akron, Akron, Ohio 44325-3601, USA.

The bis(N-heterocyclic carbene) (NHC) silver complex, 3, with a methyl carbonate anion was formed from the reaction of the iodide salt of methylated caffeine, 1, with silver (I) oxide in methanol. Attempts to crystallize this complex from a mixture of common alcohols and ethyl acetate led to the formation of an NHC-silver acetate complex, 4. The more direct synthesis of 4 was accomplished by the in-situ deprotonation of 1 by silver acetate in methanol. Complex 4 demonstrated antimicrobial activity against numerous resistant respiratory pathogens from the lungs of cystic fibrosis (CF) patients including members of the Burkholderia cepacia complex that cause a high rate of mortality in patients with cystic fibrosis (CF). Application of this NHC silver complex to primary cultures of murine respiratory epithelial cells followed by microarray analysis showed minimal gene expression changes at the concentrations effective against respiratory pathogens. Furthermore, methylated caffeine without silver showed some antibacterial and antifungal activity.
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http://dx.doi.org/10.1021/jm060711tDOI Listing
November 2006

Synthesis and characterization of a trigonal bipyramidal supramolecular cage based upon rhodium and platinum metal centers.

Chem Commun (Camb) 2006 Nov 29(44):4644-6. Epub 2006 Sep 29.

Department of Chemistry, The University of Akron, Akron, OH 44325, USA.

The reaction of 4-ethynyl-pyridine with tert-butyl lithium followed by its addition to (Me3tacn)RhCl3 affords the facial octahedral complex (Me3tacn)Rh(CCPy)3, condensation of which with the square planar complex cis-(DCPE)Pt(NO3)2 results in a self-assembled trigonal bipyramidal cage with Rh(III) and Pt(II) atoms occupying the vertices.
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http://dx.doi.org/10.1039/b608991gDOI Listing
November 2006

Lewis acid adducts of [PCl2N]3.

Inorg Chem 2005 Sep;44(19):6518-20

Department of Chemistry, University of Akron, 190 East Buchtel Commons, Akron, OH 44325-3601, USA.

Reaction of aluminum trichloride or gallium trichloride with the extremely weak base hexachlorotriphosphazene gives adducts in which the group 13 element is bound to a phosphazene nitrogen atom. In solution, the adducts exhibit fluxional behavior. The phosphazene ring of the adducts is distorted into a slight chair conformation.
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http://dx.doi.org/10.1021/ic050974yDOI Listing
September 2005

Anion directed synthesis of paddlane and trisilver tweezer complexes based upon silver coordination chemistry.

J Am Chem Soc 2005 Apr;127(16):5738-9

Addition of AgBF4 or Ag(O3SCF3) to the tripodal ligand, Me3tacnRh(CCPh)3, yields a paddlane complex as well as a novel trinuclear silver "tweezer" complex based upon silver acetylene coordination chemistry. The paddlane is composed of two Me3tacnRh(CCPh)3 moieties held together by silver acetylene interactions. The tweezer complex is composed of one tripodal moiety with three silver atoms coordinated to each acetylene-Rh-acetylene face. The tweezer complex is stabilized by additional interactions, including a triflate anion which serves to cap the complex.
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http://dx.doi.org/10.1021/ja050154kDOI Listing
April 2005

Silver(I)-imidazole cyclophane gem-diol complexes encapsulated by electrospun tecophilic nanofibers: formation of nanosilver particles and antimicrobial activity.

J Am Chem Soc 2005 Feb;127(7):2285-91

Department of Chemistry, University of Akron, Akron, Ohio 44325, USA.

Silver(I)-imidazole cyclophane gem-diol complex, 3 [Ag2C36 N10(O)4](2+)2(x)-, where x = OH- or CO3(2-), was synthesized and well characterized. The minimum inhibition concentration tests showed that the aqueous form of 3 is 2 times less effective as an antibiotic than 0.5% AgNO3, with about the same amount of silver. The antimicrobial activity of 3 was enhanced when encapsulated into Tecophilic polymer by electrospinning to obtain mats made of nano-fibers. The fiber mats released nanosilver particles, which in turn sustained the antimicrobial activity of the mats over a long period of time. The rate of bactericidal activity of 3 was greatly improved by encapsulation, and the amount of silver used was much reduced. The amount of silver contained in the fiber mat of 3, with 75% of 3 and 25% Tecophilic, was 8 times less than that in 0.5% AgNO3 and 5 times lower than that in silver sulfadiazine cream 1%. The fiber mat was found to kill S. aureus at the same rate as 0.5% AgNO3, with zero colonies on an agar plate, and about 6 times faster than silver sulfadiazine cream. The silver mats were found effective against E. coli, P. aeruginosa, S. aureus, C. albicans, A. niger, and S. cerevisiae. Transmission electron microscopy and scanning electron microscopy were used to characterize the fiber mats. The acute toxicity of the ligand (imidazolium cyclophane gem-diol dichloride) was assessed by intravenous administration to rats, with an LD 50 of 100 mg/kg of rat.
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http://dx.doi.org/10.1021/ja040226sDOI Listing
February 2005

Formation of water-soluble pincer silver(I)-carbene complexes: a novel antimicrobial agent.

J Med Chem 2004 Feb;47(4):973-7

Departments of Chemistry and Biology, University of Akron, Akron, Ohio 44325, USA.

Silver(I)-2,6-bis(ethanolimidazolemethyl)pyridine hydroxide (4a) and silver(I)-2,6-bis(propanolimidazolemethyl)pyridine hydroxide (4b) are water-soluble silver(I)-carbene complexes that were synthesized in high yield by reacting silver(I) oxide with N-substituted pincer ligands 3 (a = 2,6-bis(ethanolimidazoliummethyl)pyridine diiodide, b = 2,6-bis(propanolimidazoliummethylpyridine)pyridine dibromide). The X-ray crystal structure of 4a is a one-dimensional linear polymer, whereas the mass spectroscopy confirms a monomer in the gas phase. A change in the anion of 4a from a hydroxide to a hexafluorophosphate formed a silver(I)-carbene complex 4c that is dimeric in structure and insoluble in water. The bactericidal activities of the water-soluble silver(I)-carbene complexes were found to be improved over that of silver nitrate.
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http://dx.doi.org/10.1021/jm030262mDOI Listing
February 2004

Unusual Formation of a Cyclyne Dimer and an Indenoindene Derivative.

J Org Chem 1999 Apr;64(8):2947-2949

Department of Chemistry, University of Akron, Akron, Ohio 44325-3601.

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http://dx.doi.org/10.1021/jo982111aDOI Listing
April 1999

A Novel High-Yield Synthesis of Substituted Isoindolequinones.

J Org Chem 1997 Nov;62(23):8193-8197

Department of Chemistry, The University of Akron, Akron, Ohio 44325-3601.

The high-yield, general, one-pot synthesis of substituted isoindolequinones, a group of important radiosensitizers which sensitize hypoxic cells to the lethal effect of radiation in cancer radiotherapy, is described. Primary amines react with 2,3-bis[2-(trimethylsilyl)ethynyl]-5,6-dimethylhydroquinone (2) in methanol at room temperature under an inert atmosphere to give substituted isoindolequinones 2-alkyl-1,3,5,6-tetramethylisoindole-4,7-quinone (4) in almost quantitative yields. Moderate yields of 4 are also obtained using 2,3-diethynyl-5,6-dimethylhydroquinone (3) and amines as reactant and solvent under the similar conditions. Tris(2-aminoethyl)amine (TREN) reacts with 2 in MeOH/THF on reflux to produce the isoindolequinone derivative of TREN. Water with 2 on reflux in MeOH forms an isobenzofuranquinone. This indicates that the formation of similar heterocycles from small molecules (e.g., Group VA and VIA hydrides) and 2 is likely. Readily synthesizable starting materials, ease of chromatographic isolation of the product, reaction generality, use of no catalyst, and cost-effective environmentally benign solvents such as MeOH/EtOH make this novel reaction simple and convenient.
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http://dx.doi.org/10.1021/jo971671rDOI Listing
November 1997