0000000000462331
AUTHOR
Luca Salassa
Landomycins as glutathione-depleting agents and natural fluorescent probes for cellular Michael adduct-dependent quinone metabolism
Landomycins are angucyclines with promising antineoplastic activity produced by Streptomyces bacteria. The aglycone landomycinone is the distinctive core, while the oligosaccharide chain differs within derivatives. Herein, we report that landomycins spontaneously form Michael adducts with biothiols, including reduced cysteine and glutathione, both cell-free or intracellularly involving the benz[a]anthraquinone moiety of landomycinone. While landomycins generally do not display emissive properties, the respective Michael adducts exerted intense blue fluorescence in a glycosidic chain-dependent manner. This allowed label-free tracking of the short-lived nature of the mono-SH-adduct followed b…
Biological activity of PtIV prodrugs triggered by riboflavin-mediated bioorthogonal photocatalysis
AbstractWe have recently demonstrated that riboflavin (Rf) functions as unconventional bioorthogonal photocatalyst for the activation of PtIV prodrugs. In this study, we show how the combination of light and Rf with two PtIV prodrugs is a feasible strategy for light-mediated pancreatic cancer cell death induction. In Capan-1 cells, which have high tolerance against photodynamic therapy, Rf-mediated activation of the cisplatin and carboplatin prodrugs cis,cis,trans-[Pt(NH3)2(Cl)2(O2CCH2CH2CO2H)2] (1) and cis,cis,trans-[Pt(NH3)2(CBDCA)(O2CCH2CH2CO2H)2] (2, where CBDCA = cyclobutane dicarboxylate) resulted in pronounced reduction of the cell viability, including under hypoxia conditions. Such …
Ruthenium-arene complexes bearing naphthyl-substituted 1,3-dioxoindan-2-carboxamides ligands for G-quadruplex DNA recognition.
Quadruplex nucleic acids – DNA/RNA secondary structures formed in guanine rich sequences – proved to have key roles in the biology of cancers and, as such, in recent years they emerged as promising targets for small molecules. Many reports demonstrated that metal complexes can effectively stabilize quadruplex structures, promoting telomerase inhibition, downregulation of the expression of cancer-related genes and ultimately cancer cell death. Although extensively explored as anticancer agents, studies on the ability of ruthenium arene complexes to interact with quadruplex nucleic acids are surprisingly almost unknown. Herein, we report on the synthesis and characterization of four novel Ru(…
Anticancer platinum agents and light
Abstract Since the discovery of cisplatin, light activation has been employed as a strategy to switch and improve the anticancer effects of platinum compounds. This contribution highlights some of the most representative discoveries obtained in the field of platinum-based photochemotherapy over the years.
Near-infrared photochemistry assisted by upconverting nanoparticles
Abstract Upconverting nanoparticles (UCNPs) combine unique optical and imaging properties with high chemical and biological stability. The capability of UCNPs to emit visible light upon near-infrared light excitation, in an anti-Stokes fashion, is extremely attractive for the design of light-responsive nanomaterials whose action can be controlled spatially and temporally. In this chapter, we analyze the most promising approaches developed so far to functionalize the surface of UCNPs with photoactivatable organic and inorganic molecular systems. In particular, we emphasize the key advances in the design of upconverting nanosystems that exploit bioactive transition metal complexes.
Teaching Inorganic Photophysics and Photochemistry with Three Ruthenium(II) Polypyridyl Complexes: A Computer-Based Exercise
Among computational methods, DFT (density functional theory) and TD-DFT (time-dependent DFT) are widely used in research to describe, inter alia, the optical properties of transition metal complexes. Inorganic/physical chemistry courses for undergraduate students treat such methods, but quite often only from the theoretical point of view. In the calculation exercise herein described, students are guided step by step through the computational study of the photophysics and photochemistry of polypyridyl Ru(II) d6-metal complexes. In particular, by means of DFT and TD-DFT calculations, they are asked to examine and interpret a set of experimental data describing the absorption, emission, and ph…
124I Radiolabeling of a AuIII‐NHC Complex for In Vivo Biodistribution Studies†
Abstract AuIII complexes with N‐heterocyclic carbene (NHC) ligands have shown remarkable potential as anticancer agents, yet their fate in vivo has not been thoroughly examined and understood. Reported herein is the synthesis of new AuIII‐NHC complexes by direct oxidation with radioactive [124I]I2 as a valuable strategy to monitor the in vivo biodistribution of this class of compounds using positron emission tomography (PET). While in vitro analyses provide direct evidence for the importance of AuIII‐to‐AuI reduction to achieve full anticancer activity, in vivo studies reveal that a fraction of the AuIII‐NHC prodrug is not immediately reduced after administration but able to reach the major…
Catalysis Concepts in Medicinal Inorganic Chemistry
Catalysis has strongly emerged in the field of medicinal inorganic chemistry as a suitable tool to deliver new drug candidates and to overcome drawbacks associated to metallodrugs. In this Concept article, we discuss representative examples of how catalysis has been applied in combination with metal complexes to deliver new therapy approaches. In particular, we explain key achievements in the design of catalytic metallodrugs that damage biomolecular targets and in the development of metal catalysis schemes for the activation of exogenous organic prodrugs. Moreover, we discuss our recent discoveries on the flavin-mediated bioorthogonal catalytic activation of metal-based prodrugs; a new cata…
CCDC 1989307: Experimental Crystal Structure Determination
Related Article: Federica Guarra, Alessio Terenzi, Christine Pirker, Rossana Passannante, Dina Baier, Ennio Zangrando, Vanessa G��mez���Vallejo, Tarita Biver, Chiara Gabbiani, Walter Berger, Jordi Llop, Luca Salassa|2020|Angew.Chem.,Int.Ed.|59|17130|doi:10.1002/anie.202008046
CCDC 1870492: Experimental Crystal Structure Determination
Related Article: Laura A. Hager, Stephan Mokesch, Claudia Kieler, Silvia Alonso-de Castro, Dina Baier, Alexander Roller, Wolfgang Kandioller, Bernhard K. Keppler, Walter Berger, Luca Salassa, Alessio Terenzi|2019|Dalton Trans.|48|12040|doi:10.1039/C9DT02078K
CCDC 1989306: Experimental Crystal Structure Determination
Related Article: Federica Guarra, Alessio Terenzi, Christine Pirker, Rossana Passannante, Dina Baier, Ennio Zangrando, Vanessa G��mez���Vallejo, Tarita Biver, Chiara Gabbiani, Walter Berger, Jordi Llop, Luca Salassa|2020|Angew.Chem.,Int.Ed.|59|17130|doi:10.1002/anie.202008046
CCDC 1870494: Experimental Crystal Structure Determination
Related Article: Laura A. Hager, Stephan Mokesch, Claudia Kieler, Silvia Alonso-de Castro, Dina Baier, Alexander Roller, Wolfgang Kandioller, Bernhard K. Keppler, Walter Berger, Luca Salassa, Alessio Terenzi|2019|Dalton Trans.|48|12040|doi:10.1039/C9DT02078K
CCDC 1870493: Experimental Crystal Structure Determination
Related Article: Laura A. Hager, Stephan Mokesch, Claudia Kieler, Silvia Alonso-de Castro, Dina Baier, Alexander Roller, Wolfgang Kandioller, Bernhard K. Keppler, Walter Berger, Luca Salassa, Alessio Terenzi|2019|Dalton Trans.|48|12040|doi:10.1039/C9DT02078K