Multimetallic Alkenyl Complexes Bearing Macrocyclic Dithiocarbamate Ligands

Toscani, Anita; Heliövaara, Eeva; Hena, Jubeda B.; White, Andrew J. P.; Wilton‐Ely, James D. E. T.

doi:10.1021/om5011269

Cited by 17 publications

(5 citation statements)

References 139 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is known that generation of the dithiocarbamate from the amine greatly increases its reactivity so precursor 8 was used for storage of the surface unit. When desired, the addition of K 2 CO 3 followed by carbon disulfide, leads to the in situ formation of the expected dithiocarbamate moiety ( 9 ), in line with our previous studies on piperazine‐based dithiocarbamate complexes . High‐resolution mass spectrometry confirmed the generation of 9 ( m / z 812.1283 for [ M +K] + ), while solid state infrared absorptions measured for 9 attributed to ν(CN) and ν(CS) at 1427 and 1002 cm −1 , respectively, provided evidence for the formation of the dithiocarbamate.…”

Section: Resultsmentioning

confidence: 99%

“…When desired, the addition of K 2 CO 3 followed by carbon disulfide, leads to the in situ formation of the expected dithiocarbamate moiety (9), in line with our previous studies on piperazine-based dithiocarbamate complexes. [35,36,38,44,[49][50][51][52][53][54][55] High-resolution mass spectrometry confirmed the generation of 9 (m/z 812.1283f or [M+ +K] + ), while solid state infrared absorptions measured for 9 attributed to n(CN) and n(CS) at 1427 and 1002 cm À1 ,r espectively,p rovided evidencefor the formationofthe dithiocarbamate. This was reinforcedb yaresonance at 209.5 ppm in the 13 C{ 1 H} NMR spectrum obtained for the diamagneticl anthanum (La 3 + ,f 0 )a nalogue of 9,formed in an identical fashion.…”

Section: Synthesis Of Anovel Gadolinium Surface Unitmentioning

confidence: 90%

See 1 more Smart Citation

Combined Magnetic Resonance Imaging and Photodynamic Therapy Using Polyfunctionalised Nanoparticles Bearing Robust Gadolinium Surface Units

Chabloz

Perry

Yoon

et al. 2020

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

A robust dithiocarbamate tether allows novel gadolinium units based on DOTAGA (q=1) to be attached to the surface of gold nanoparticles (2.6–4.1 nm diameter) along with functional units offering biocompatibility, targeting and photodynamic therapy. A dramatic increase in relaxivity (r1) per Gd unit from 5.01 mm−1 s−1 in unbound form to 31.68 mm−1 s−1 (10 MHz, 37 °C) is observed when immobilised on the surface due to restricted rotation and enhanced rigidity of the Gd complex on the nanoparticle surface. The single‐step synthetic route provides a straightforward and versatile way of preparing multifunctional gold nanoparticles, including examples with conjugated zinc–tetraphenylporphyrin photosensitizers. The lack of toxicity of these materials (MTT assays) is transformed on irradiation of HeLa cells for 30 minutes (PDT), leading to 75 % cell death. In addition to passive targeting, the inclusion of units capable of actively targeting overexpressed folate receptors illustrates the potential of these assemblies as targeted theranostic agents.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Synthesis Of Anovel Gadolinium Surface Unitmentioning

confidence: 90%

Combined Magnetic Resonance Imaging and Photodynamic Therapy Using Polyfunctionalised Nanoparticles Bearing Robust Gadolinium Surface Units

Chabloz

Perry

Yoon

et al. 2020

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…The benefit of using reliable linkers, such as pyridyl donors, to form multimetallic d–f hybrids for use in imaging applications has been demonstrated by Faulkner and co-workers . While less frequently employed than nitrogen-based donors, the dependable reactivity and versatility of dithiocarbamate ligands make them ideally suited to the construction of multimetallic assemblies . Accordingly, the dithiocarbamate Gd-DO3A-DTC was used to prepare a series of multimeric molecular gadolinium compounds through the addition of suitable transition-metal precursors (Scheme ).…”

Section: Resultsmentioning

confidence: 99%

“…For over a decade, we have focused on the development of a wide range of routes to multimetallic compounds, with the use of dithiocarbamates (R 2 NCS 2 – ) being a recurring feature . This has been driven partly by the ease of formation of dithiocarbamates from (usually secondary) amines in the presence of base and carbon disulfide .…”

Section: Introductionmentioning

confidence: 99%

Metallostar Assemblies Based on Dithiocarbamates for Use as MRI Contrast Agents

et al. 2020

Self Cite

View full text Add to dashboard Cite

Two different octadentate gadolinium chelates based on DO3A and DOTAGA chelates (hydration number q = 1) have been used to prepare a series of bi-, tri-and tetrametallic d-f mixed-metal complexes. The piperazine-based dithiocarbamate linker ensures that rotation of the gadolinium chelates is restricted, leading to enhanced relaxivity (r1) values, which increase with overall mass and the number of gadolinium units. The r1 value (at 10 MHz, 25 °C) per Gd unit rises from 5.0 mM −1 s −1 for the Gd-DO3A-NH2 monogadolinium chelate to 9.2 mM −1 s −1 in a trigadolinium complex with a ruthenium(III) core. Using a 1.5 T clinical scanner operating at 63.87 MHz (25 °C), an 86% increase in relaxivity per gadolinium unit is observed for this multimetallic compound compared to clinically-approved Dotarem. The gadolinium complexes based on the DOTAGA chelate also performed well at 63.87 MHz, with a relaxivity value of 9.5 mM −1 s −1 per gadolinium unit being observed for the trigadolinium d-f mixed-metal complex with a ruthenium(III) core. The versatility of dithiocarbamate coordination chemistry thus provides access to a wide range of d-f hybrids with potential for use as high-performance MRI contrast agents.

show abstract

“…Considering these precedents, we feel that crown ether-based dithiocarbamate metal complexes might be a reasonable starting point for designing new antineoplastic platinum drugs. Although a relatively large variety of metal complexes with aza crown ether-dtc ligands have been reported with different purposes, − it is surprising that, to date, no platinum or palladium derivative has been described. Herein we present the first examples of aza crown ether-dtc complexes with these metal ions and an evaluation of cytotoxic activity against some human tumor cells, namely Hela-229 cervix and A2780 ovarian carcinoma cells, as well as against the cisplatin-resistant mutant A2780 cis .…”

Section: Introductionmentioning

confidence: 99%

Further Approaches in the Design of Antitumor Agents with Response to Cell Resistance: Looking toward Aza Crown Ether-dtc Complexes

et al. 2020

View full text Add to dashboard Cite

The dianionic aza crown ether-dtc N,N′-bis-(dithiocarbamate)-1,10-diaza-18-crown-6 (L 2− ) is a versatile ligand capable of yielding binuclear complexes with group 10 elements, also known as Ni-triade, [μ-(κ 2 -S,-S′-L)M 2 (PPh 3 ) 4 ]Cl 2 (M = Pd (1), Pt (2)), [μ-(κ 2 -S,-S′-L)M 2 (PPh 3 ) 4 ](BPh 4 ) 2 (M = Pd (3), Pt (4)), and μ-(κ-S,-S′-L)Ni 2 (PPh 3 ) 2 Cl 2 ( 5), and has proven to be an excellent option to the design of metal-based drugs able to provide multiple response to cell resistance. Palladium and platinum complexes, 1 and 2, were tested for cytotoxicity in the human cervix carcinoma cell line HeLa-229, the human ovarian carcinoma cell line A2780, and the cisplatin-resistant mutant A2780cis, finding significant activity toward all three cancer cell lines, with low micromolar IC 50 values, comparable to cisplatin. Markedly, against the cisplatin resistant cell line A2780cis, compound 2 exhibits better cytotoxic activity than the clinical drug (IC 50 = 2.3 ± 0.2 μM for 2 versus 3.6 ± 0.5 μM for cisplatin). Moreover, an enhancement of the antitumor response is achieved when adding an equimolar amount of alkali metal chloride (NaCl or KCl) to the medium, for instance, testing compound 1 against the cisplatin-resistant A2780cis cells, the IC 50 decreases from 9.3 ± 0.4 to 7.4 ± 0.3 and 5.4 ± 0.1 μM, respectively, after addition of the salt solution. For the platinum derivative 2, the IC 50 improves by ca. 40% reaching 1.3 ± 0.1 μM when potassium chloride is added. Likewise, the resistant factor found for 2 (RF = 1) confirms that this complex circumvents cisplatin-resistance in A2780cis and is improved with the addition of potassium chloride (RF = 0.65). The presence of the aza crown ether moiety as linker in the systems studied herein is a key point since, in addition to allowing and facilitating interaction with alkali metal ions, this unit is flexible enough to adapt to a variety of environments, as confirmed by the Xray crystal structures described, where different conformations and ways to fold in are found. In order to gain insight into the electronic and structural facts involved in the interaction of complex 2 with the alkali metal ions, a DFT study was performed, and the description of the molecular electrostatic potentials (MEPs) is also presented.

show abstract

Multimetallic Alkenyl Complexes Bearing Macrocyclic Dithiocarbamate Ligands

Abstract: The aza-crown ether compounds, 1-aza-15-crown-5 and 1,10-diaza-18-crown-6 react with sodium hydroxide and carbon disulfide to provide the dithiocarbamates, [15]

Cited by 17 publications

References 139 publications

Combined Magnetic Resonance Imaging and Photodynamic Therapy Using Polyfunctionalised Nanoparticles Bearing Robust Gadolinium Surface Units

Combined Magnetic Resonance Imaging and Photodynamic Therapy Using Polyfunctionalised Nanoparticles Bearing Robust Gadolinium Surface Units

Metallostar Assemblies Based on Dithiocarbamates for Use as MRI Contrast Agents

Further Approaches in the Design of Antitumor Agents with Response to Cell Resistance: Looking toward Aza Crown Ether-dtc Complexes

Contact Info

Product

Resources

About