Université de Fribourg

Modified biovectors for the tuneable activation of anti-platelet carbon monoxide release

Prieto, Lucas ; Rossier, Jeremie ; Derszniak, Katarzyna ; Dybas, Jakub ; Oetterli, René M. ; Kottelat, Emmanuel ; Chlopicki, Stefan ; Zelder, Felix ; Zobi, Fabio

In: Chemical Communications, 2017, vol. 53, no. 51, p. 6840–6843

This communication describes the anti-platelet effects of a new class of cis-rhenium(II)- dicarbonyl-vitamin B12 complexes (B12-ReCORMs) with tuneable CO releasing properties.

Université de Fribourg

Correlation of surface pressure and hue of planarizable push-pull chromophores at the air/water interface

Neuhaus, Frederik ; Zobi, Fabio ; Brezesinski, Gerald ; Molin, Marta Dal ; Matile, Stefan ; Zumbuehl, Andreas

In: Beilstein Journal of Organic Chemistry, 2017, vol. 13, no. 1, p. 1099–1105

It is currently not possible to directly measure the lateral pressure of a biomembrane. Mechanoresponsive fluorescent probes are an elegant solution to this problem but it requires first the establishment of a direct correlation between the membrane surface pressure and the induced color change of the probe. Here, we analyze planarizable dithienothiophene push–pull probes in a monolayer at...

Université de Fribourg

Heptacoordinate Coii complex: a new architecture for photochemical hydrogen production

Lucarini, Fiorella ; Pastore, Mariachiara ; Vasylevskyi, Serhii ; Varisco, Massimo ; Solari, Euro ; Crochet, Aurelien ; Fromm, Katharina M. ; Zobi, Fabio ; Ruggi, Albert

In: Chemistry - A European Journal, 2017, p. -

The first heptacoordinate cobalt catalyst for light-driven hydrogen production in water has been synthesized and characterized. Photochemical experiments using [Ru(bpy)₃]²⁺ as photosensitizer gave a turnover number (TON) of 16300 mol H₂ (mol cat.)⁻¹ achieved in 2 hours of irradiation with visible (475 nm) light. This promising result provides a path forward in the...

Université de Fribourg

Organometallic cobalamin anticancer derivatives for targeted prodrug delivery via transcobalamin-mediated uptake

Rossier, Jeremie ; Hauser, Daniel ; Kottelat, Emmanuel ; Rothen-Rutishauser, Barbara ; Zobi, Fabio

In: Dalton Transactions, 2017, vol. 46, no. 7, p. 2159–2164

Herein we report the synthesis of new water-soluble vitamin B12 prodrugs bearing metal complexes at the β-upper side of the cobalt center. A total of three derivatives with the general design {Co–C[triple bond, length as m-dash]C-bpy–M}, where M represents a cytotoxic metal complex, were prepared and tested for their cytotoxicity against MCF-7 breast cancer cells. The choice of the metal...

Université de Fribourg

Red-light activated photoCORMs of Mn(I) species bearing electron deficient 2,2′-azopyridines

Kottelat, Emmanuel ; Ruggi, Albert ; Zobi, Fabio

In: Dalton Transactions, 2016, vol. 45, no. 16, p. 6920–6927

The realization of CO releasing molecules triggered by light (photoCORMs) within the phototherapeutic window (λ > 600 nm) constitutes an important goal for potential therapeutic applications of the molecules. The activation of photoCORMs with red/NIR light would enable exploiting the higher depth of penetration of this radiation with respect to higher energy photons. In this article we...

Université de Fribourg

Heme oxygenase-1/carbon monoxide system and embryonic stem cell differentiation and maturation into cardiomyocytes

Suliman, Hagir B. ; Zobi, Fabio ; Piantadosi, Claude A.

In: Antioxidants & Redox Signaling, 2016, vol. 24, no. 7, p. 345–360

The differentiation of embryonic stem (ES) cells into energetically efficient cardiomyocytes contributes to functional cardiac repair and is envisioned to ameliorate progressive degenerative cardiac diseases. Advanced cell maturation strategies are therefore needed to create abundant mature cardiomyocytes. In this study, we tested whether the redox-sensitive heme oxygenase-1/carbon monoxide...

Université de Fribourg

N-Nitrosamine-{cis--Re[CO]₂}²⁺ cobalamin conjugates as mixed CO/NO-releasing molecules

Santoro, Giuseppe ; Beltrami, Ruben ; Kottela, Emmanuel ; Blacque, Olivier ; Bogdanova, Anna Yu. ; Zobi, Fabio

In: Dalton Transactions, 2016, vol. 45, no. 4, p. 1504–1513

Mixed CO/NO-releasing molecules were prepared by conjugation of the 17-electron rhenium dicarbonyl cis-[Re(CO)₂Br₄]²⁻ complex to N-nitrosamine modified cyanocobalamin (B12) bio-vectors. The species were fully characterized by standard analytical techniques, including X-ray crystallography for cyanocobalamin-5′-O-pyrazine and (1) and its...

Université de Fribourg

Towards cardiolite-inspired carbon monoxide releasing molecules – Reactivity of d4, d5 rhenium and d6 manganese carb­onyl complexes with isocyanide ligands

Kottelat, Emmanuel ; Chabert, Valentin ; Crochet, Aurélien ; Fromm, Katharina M. ; Zobi, Fabio

In: European Journal of Inorganic Chemistry, 2015, vol. 2015, no. 34, p. 5628–5638

Carbon monoxide releasing molecules (CORMs) are investigated widely in synthetic and medicinal chemistry owing to the potential therapeutic applications of the CO gas. Organometallic carbonyl complexes are best suited to play the role of CO carriers as they allow the exogenous release of CO under controlled conditions, and the toxicity of the gas can be overcome. With the long-term goal of...

Université de Fribourg

Quantum-CORMs: quantum dot sensitized CO releasing molecules

Ruggi, Albert ; Zobi, Fabio

In: Dalton Transactions, 2015, vol. 44, no. 24, p. 10928–10931

The synthesis and photodecomposition behaviour of a family of CO releasing molecules (CORMs) based on [Mn(CO)₃bpy] derivatives connected to a semiconductor Quantum Dot (QD) sensitizer is described here. Compared to the non-sensitized complexes, such systems show a 2 to 6-fold increase of the photodecomposition rate upon irradiation with visible light.

Université de Fribourg

Synthesis, characterization and cellular location of cytotoxic constitutional organometallic isomers of rhenium delivered on a cyanocobalmin scaffold

Santoro, Giuseppe ; Zlateva, Theodora ; Ruggi, Albert ; Quaroni, Luca ; Zobi, Fabio

In: Dalton Transactions, 2015, vol. 44, no. 15, p. 6999–7008

Constitutional isomers of cyanocobalamin adducts based on a fluorescent rhenium tris-carbonyl diimine complex were prepared, characterized and tested against PC-3 cancer cells. The adducts differ only in the relative binding position of the organometallic species which is either bound at the cyano or the 5′-hydroxo group of vitamin B₁₂. When tested for their cytotoxic potency, the species...