Dalton Transactions

doi: 10.1039/d3dt90094kpmid: N/A

doi: 10.1039/d3dt90095apmid: N/A

doi: 10.1039/d3dt90096gpmid: N/A

Kumar, Pramod; Tomar, Sunil; Kumar, Krishan; Kumar, Sushil

doi: 10.1039/d3dt00368jpmid: 37128993

Chemical nucleases have found potential applications in the research fields of chemistry, biotechnology and medicine. A variety of metal complexes have been explored as good to outstanding therapeutic agents for DNA cleavage activity most likely via hydrolytic, oxidative or photoinduced cleavage pathways. However, most of these DNA cleaving agents lack their utility in in vivo applications due to their dependence on exogenous oxidants or reductants to achieve successful DNA damage. In view of addressing these issues, the development of metal complexes/organic molecules serving as self-activating chemical nucleases has received growing attention from researchers. In only the last decade, this field has dramatically expanded for the usage of chemical nucleases as therapeutic agents for DNA damage. The present study provides an overview of the opportunities and challenges in the design and development of self-activating chemical nucleases as improved DNA therapeutic candidates in the absence of an external redox agent. The reports on DNA nuclease activity via self-activation, especially with copper, zinc and iron complexes, and their mechanistic investigation have been discussed in this review article.

Kou, Junfeng; Shen, Jinchao; Lin, Mingwei; Xiong, Kai; Wang, Lili; Wei, Fangmian; Zhang, Junfeng

doi: 10.1039/d3dt00537bpmid: 37067849

Four novel PSs (photosensitizers) of nitrogen-heterocyclic ruthenium polypyridyl complexes Ru(dip)2(o-pipppz)(PF6)2 (Ru1) (dip = 4,7-diphenyl-1,10-phenanthroline; o-pipppz = 1-(4-aldehydephenyl)-3-(pyridazyl-2-yl)-1H-pyrazole), Ru(dip)2(o-pipp) (PF6)2 (Ru2) (o-pipp = 1-(4-aldehydephenyl)-3-(pyrid-2-yl)-1H-pyrazole), Ru(dip)2(m-pipp)(PF6)2 (Ru3) (m-pipp = 1-(4-aldehydephenyl)-3-(pyrid-3-yl)-1H-pyrazole) and Ru(dip)2(p-pipp)(PF6)2 (Ru4) (p-pipp = 1-(4-aldehydephenyl)-3-(pyrid-4-yl)-1H-pyrazole) were reported, and the photodynamic activities of these complexes were studied on 2D and 3D HeLa cancer models. The longest visible absorption wavelength of these complexes was approximately 622 nm. The four Ru(ii) complexes show preferable photodynamic activity and low dark toxicity (0.2–0.4 μM) in vitro against 2D HeLa tumor cells. These complexes exhibit very high singlet oxygen quantum yields in methanol (0.70–0.95), TPA cross-sections (7–31 GM), and high penetration depth. Thus, Ru1–Ru4 were utilized as one-photon and two-photon absorbing photosensitizers in both monolayer cells and 3D multicellular spheroids (MCSs). Among them, Ru2 revealed a higher singlet oxygen yield (0.95), a larger TPA cross-section (31 GM), and the strongest phototoxicity (EC50 = 0.20 μM). Moreover, flow cytometry shows that the four Ru(ii) complexes can induced cell death mainly through apoptosis upon singlet oxygen-dependent reaction.

Wang, Haibin; Chen, Lantao; Xu, Feng; Zhang, Yufei; Fan, Haosen

doi: 10.1039/d3dt01100cpmid: 37166174

Hierarchical Co1−xS/MnS/NC nanowires have been successfully prepared by a simple hydrothermal reaction and the subsequent annealing process of its one-dimensional (1D) coordination polymer precursors. The Co1−x/MnS/NC heterostructure nanowires can not only buffer the volume expansion during the discharging and charging process but also conspicuously enhance electronic conductivity, which is favourable for improving the rate performance and cycling stability, which can maintain 612.9 mA h g−1 after 100 cycles at 0.5 A g−1 and 544.6 mA h g−1 after 200 cycles at 1.0 A g−1 for SIBs.

Tito, Gabriella; Troisi, Romualdo; Ferraro, Giarita; Geri, Andrea; Massai, Lara; Messori, Luigi; Sica, Filomena; Merlino, Antonello

doi: 10.1039/d3dt00320epmid: 37199244

The reaction of the cytotoxic compound dirhodium tetraacetate with a B-DNA double helical dodecamer was studied by X-ray crystallography and mass spectrometry. The structure of the dirhodium/DNA adduct reveals a dimetallic center binding to an adenine via axial coordination. Complementary information has been gained through ESI MS measurements. Comparison between the present data and those previously obtained for cisplatin indicates that the two metallodrugs react with this DNA dodecamer in a significantly different fashion.

Savva, Maria; Alexandropoulos, Dimitris I.; Pissas, Michael; Perlepes, Spyros P.; Papatriantafyllopoulou, Constantina; Sanakis, Yiannis; Tasiopoulos, Anastasios J.

doi: 10.1039/d2dt03938apmid: 36789752

The synthesis, crystal structures, Mössbauer spectra and variable temperature dc and ac magnetic susceptibility studies of a new family of trinuclear heterometallic Fe3+/Ln3+ complexes, [Fe2Ln(PhCO2)3((py)2CO2)((py)2C(OMe)O)2(NO3)Cl] (Ln = Gd (1/Gd), Tb (1/Tb), Dy (1/Dy), and Ho (1/Ho)), where (py)2CO22− and (py)2C(OMe)O− are the anions of the gem-diol and hemiketal derivatives of di-2-pyridyl ketone, are reported. Compounds 1/Ln are based on an asymmetric “V-shaped” [Fe3+(μ-OR)Ln(μ-OR)2Fe3+]6+ structural core formed from the connection of the two terminal Fe3+ centers to the central Ln3+ ion either through one or two alkoxide groups originating from the alkoxide-type bridging ligands. Direct current magnetic susceptibility studies reveal the presence of weak antiferromagnetic interactions between the Fe3+ ions. Alternating current magnetic studies indicate the presence of a slow-magnetic relaxation process in 1/Dy with an energy barrier Ueff = 6.7 (±0.3) K and a pre-exponential factor, τ0 = 2.2 (±0.4) × 10−7 s. The electronic, magnetic and relaxation properties of the complexes were further monitored by variable temperature 57Fe Mössbauer spectroscopy. At T > 80 K the spectra from the complexes comprise two quadrupole doublets the hyperfine parameters of which reflect the distinct coordination environment of the two Fe3+ terminal sites. At T < 20 K, the Mössbauer spectra for 1/Dy are affected by magnetic relaxation effects. At 1.5 K, the spectrum of 1/Dy comprises well defined magnetic sextets indicating relaxation times slower than the characteristic time of the Mössbauer technique (10−7 s) in agreement with the dynamic magnetic measurements. 1/Gd exhibits broad unresolved magnetic sextets at 1.5 K indicating that the spin relaxation time is of the order of the Mössbauer characteristic time at this temperature. For 1/Tb, 1/Ho the Mössbauer spectra exhibit slight broadening even at the lowest available temperature consistent with magnetic relaxation times less than 10−7 s.

Farajzadeh, Nazli; Yasemin Yenilmez, H.; Bahar, Dilek; Kuşçulu, Nilgün Güler; Selvi, Emine Kılıçkaya; Bayır, Zehra Altuntaş

doi: 10.1039/d3dt00615hpmid: 37092282

This study reports the synthesis and characterization of two new mono- and di-substituted phthalonitriles namely 4-((9H-carbazol-3-yl)oxy)-5-chlorophthalonitrile and 4,5-bis((9H-carbazol-3-yl)oxy)phthalonitrile, respectively. Cyclotetramerization of the new phthalonitriles in the presence of zinc(ii) acetate resulted in related zinc(ii) phthalocyanines. To study the effect of the position and number of substituents on the biological properties of the phthalocyanines, peripherally or non-peripherally tetra-substituted zinc(ii) phthalocyanines bearing (9H-carbazol-3-yl)oxy groups, as well as axially di-substituted silicon phthalocyanines containing the same groups, were prepared. Since gold nanoparticles are well-known as efficient drug delivery agents, the surface of these metal nanoparticles was functionalized with all the compounds. This modification also improved the solubility of the phthalocyanines in aqueous media. In this study, the antioxidant, DNA cleavage, and toxic/phototoxic activities of the resultant nanoconjugates were examined. With a combination of metal ion and substituent (nature, number, and position) effects, the silicon(iv) phthalocyanine exhibited the highest biological properties.

Hou, Yameng; Mu, Lei; Zhou, Sijin; Xu, Yicheng; Kong, Xianglei

doi: 10.1039/d3dt00681fpmid: 37195033

Nowadays, focus is on encapsulating a greater variety and amount of metal species into fullerene cages due to their diverse structures and fascinating properties. Nevertheless, the encapsulation of more positively charged metal atoms inside one cage means more Coulomb repulsion, which makes the formation of such endohedral metallofullerenes (EMFs) difficult. In general, non-metallic atoms such as N and O should be introduced as mediators for the formation of trimetallic or tetrametallic endohedral fullerenes. However, it is still unknown whether metal atoms can serve as mediators themselves to form such EMFs. In this paper, the endohedral tetrametallic fullerene La3Pt@C98 with the platinum atom as a metallic mediator is reported. The EMFs of La3Pt@C2n (2n = 98–300) were generated by the method of laser ablation in the gas phase and verified by mass spectrometry. Among them, the EMF of La3Pt@C98 was selected and studied by theoretical calculations. Results show that the two most stable isomers are La3Pt@C2(231010)-C98 and La3Pt@C1(231005)-C98. For both of them, the inner La3Pt metallic cluster appears in a pyramidal shape, different from the planar triangular pattern of La3N clusters previously reported. Further calculations prove the existence of encaged La–Pt bonds in the La3Pt cluster. It was also revealed that the negatively charged Pt atom is situated near the center of the four-center two-electron (4c–2e) metal bond with the highest occupancy number. The platinum-mediated cluster stabilizes the EMFs greatly, promising the possibility of synthesizing new species of Pt-containing EMFs.