Platinum complexes containing adenine-based ligands: An overview of selected structural features

Tunable multi-enzyme activities of platinum nanoclusters for enhanced specificity and sensitivity in biosensing

Nanozymes have gained prominence for their utility in biosensing and disease diagnostics. However, challenges arise from complex sample matrices and nonspecific enzyme activities that contribute to false signals. This study introduces multifunctional platinum nanoclusters (Pt NCs) exhibiting peroxidase-like (POD-like), oxidase-like (OXD-like), and laccase-like activities tailored for enhanced biosensing capabilities. By adjusting pH, we optimized the conditions to achieve distinct POD-like and OXD-like responses, thereby reducing background signals and improving detection accuracy. The addition of ATP further amplified the POD-like activity while minimizing interference from OXD-like activity. This combined strategy substantially enhanced biomarker detection selectivity, demonstrated through glucose detection in human serum samples. Moreover, thiol inhibition of laccase-like activity in Pt NCs was leveraged for thiol-based antioxidant assessment, revealing their application in quantifying total antioxidant capacity (TAC) in human liver cancer cells, accounting for 44 % of TAC. The Pt NCs demonstrated robust sensitivity and reusability, offering a novel multi-enzyme nanomaterial with potential for precise and interference-free biosensing applications. These findings contribute to the development of advanced nanozyme-based biosensors, addressing specificity regulation challenges and expanding their practical application in biosensing and disease diagnostics.

Platinum-Nucleos(t)ide Compounds as Possible Antimetabolites for Antitumor/Antiviral Therapy: Properties and Perspectives

Nucleoside analogues (NAs) are a family of compounds which include a variety of purine and pyrimidine derivatives, widely used as anticancer and antiviral agents. For their ability to compete with physiological nucleosides, NAs act as antimetabolites exerting their activity by interfering with the synthesis of nucleic acids. Much progress in the comprehension of their molecular mechanisms has been made, including providing new strategies for potentiating anticancer/antiviral activity. Among these strategies, new platinum-NAs showing a good potential to improve the therapeutic indices of NAs have been synthesized and studied. This short review aims to describe the properties and future perspectives of platinum-NAs, proposing these complexes as a new class of antimetabolites.

State of art in the chemistry of nucleoside-based Pt(II) complexes

After the fortuitous discovery of the anticancer properties of cisplatin, many Pt(II) complexes have been synthesized, to obtain less toxic leads which could overcome the resistance phenomena. Given the importance of nucleosides and nucleotides as antimetabolites, studying their coordinating properties towards Pt(II) ions is challenging for bioorganic and medicinal chemistry. This review aims to describe the results achieved so far in the aforementioned field, paying particular attention to the synthetic aspects, the chemical-physical characterization, and the biological activities of the nucleoside-based Pt(II) complexes.

Undervalued N3 Coordination Revealed in the Cisplatin Complex with 2'-Deoxyadenosine-5'-monophosphate by a Combined IRMPD and Theoretical Study

The complex obtained by the reaction of cisplatin and 2'-deoxyadenosine-5'-monophosphate (5'-dAMP) in water has been isolated and detected by electrospray ionization mass spectrometry. The so-formed cis-[PtCl(NH₃)₂(5'-dAMP)]⁺ complex has been studied in detail by infrared multiple photon dissociation (IRMPD) spectroscopy in two spectral ranges, namely, 700-1900 and 2800-3800 cm^-1, backed by quantum-chemical calculations at the B3LYP/LACV3P/6-311G** level of theory. In agreement with the computational results, the vibrational spectroscopic characterization of cis-[PtCl(NH₃)₂(5'-dAMP)]⁺ shows that the sampled ionic population comprises two major isomers, differentiated in the X-H stretching region by their distinct fragmentation patterns. One of these species presents coordination of the platinum moiety at the N3 position of adenine, whereas in the second one, platinum is bound at the N1 position of adenine. IRMPD kinetics have allowed an estimation of their relative proportions. Surprisingly, the most abundant component of cis-[PtCl(NH₃)₂(5'-dAMP)]⁺ is the N3 isomer, although it is slightly less stable than the other potential isomers in the gas phase. In contrast, the lowest-energy species, namely, the one showing cisplatin binding to the N7 position of adenine, seems to be the one less represented in the sampled ionic population. These findings suggest that the reaction of cisplatin with 5'-dAMP is governed by the kinetics of the process occurring in solution rather than by the thermodynamic factors.

Directed adenine functionalization for creating complex architectures for material and biological applications

In this feature article, targeted design strategies are outlined for modified adenine nucleobase derivatives in order to construct metal-mediated discrete complexes, ring-expanded purine skeletons, linear and catenated coordination polymers, shape-selective MOFs, and purine-capped nanoparticles, with a wide range of applications from gas and solvent adsorption to bioimaging agents and anticancer metallodrugs. The success of such design strategies could be ascribed to the rich chemistry of purine and pyrimidine derivatives, versatile coordination behavior, ability to bind a host of metal ions, which could be further tuned by the introduction of additional functionalities, and their inherent propensity to hydrogen bond and exhibit π-π interactions. These noncovalent interactions produce stable frameworks and network solids that are useful as advanced materials, and the biocompatibility of these ligand complexes provides an impetus for assessing novel biological applications.

The first X-ray structure of a silver–nucleotide complex: interaction of ion Ag(i) with cytidine-5′-monophosphate

The synthesis and X-ray characterization of an unprecedented complex of Ag(i) with cytidine-5′-monophosphate (HCMP) is reported. The coordination of Ag(i) to HCMP is via both the N3 and O2 atoms of two cytosine moieties and the phosphate group, generating a MOF.

Anionic cyclometallated Pt(ii) square-planar complexes: new sets of highly luminescent compounds

Novel anionic Pt(ii) complexes were synthesized, displaying an outstanding enhancement of the emission efficiency in the solid state.