Gutenberg Open Science

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Recent Submissions

  • Item type: Item , ZeitschriftenaufsatzAccess status: Open Access ,
    1,4-Oxazepan-7-one trifluoroacetate: a modular monomer precursor for the synthesis of functional and biodegradable poly(amino esters)
    (2025) Mackiol, Tino; Pascouau, Chloé; Nagel, Manuel; Bizmark, Tamara M.; Montesel, Luca; Fischer-Schuch, Jochen; Besenius, Pol
    N-Acylated poly(amino esters) (PAEs) synthesized via organocatalytic ring-opening polymerization (ROP) offer potential for tailored, functional and degradable polymers. In this study, a universal monomer precursor toward N-acylated-1,4-oxazepan-7-ones (OxP)s was synthesized using a three-step approach, allowing for the introduction of various functional groups. Two novel oxidation sensitive OxP monomers bearing a double bond and a sulfide group were designed, as well as two monomers with alkyl moieties. The organocatalytic ROP of the OxP monomers using 1,8-diazabicyclo[5.4.0]undec-7-en (DBU) and 1-(3,5-bis(trifluoromethyl)phenyl)-3-cyclohexyl thiourea (TU) as catalysts was investigated. Polymerizations were performed under ambient temperature, affording homopolymers with narrow dispersities (Ð = 1.09–1.13). As a proof of concept, a post-polymerization thiol–ene functionalization of the allyl functional PAE was performed via photo-rheology experiments. Finally, the (bio)degradability of the N-acylated poly(amino esters) was evaluated through a series of degradation studies under mild enzymatic catalysis, in neutral phosphate-buffered saline solution and under accelerated conditions.
  • Item type: Item , ZeitschriftenaufsatzAccess status: Open Access ,
    Structure-guided design of a methyltransferase-like 3 (METTL3) proteolysis targeting chimera (PROTAC) incorporating an indole–nicotinamide chemotype
    (2025) Weldert, Annabelle C.; Frey, Ariane F.; Krone, Mackenzie W.; Krähe, Franziska; Kuhn, Hannah; Kersten, Christian; Barthels, Fabian
    Methyltransferase-like 3 (METTL3) is the main catalytic subunit of the m6A methyltransferase complex (MTC) and plays an essential role in various disease indications, including acute myeloid leukemia (AML). Here, we describe the structure-guided design and evaluation of METTL3 proteolysis-targeting chimeras (PROTACs), starting from the potent small-molecule inhibitor STM2457. Across four design generations, we highlight key considerations, particularly regarding the exit vector, linker mechanics, and METTL3-binding chemotype composition. Our most effective PROTAC, AF151, forms a stable complex between the E3 ligase von Hippel–Lindau (VHL) and the target-of-interest METTL3, demonstrating efficient METTL3 degradation (DC50 = 430 nM) in the AML cell line MOLM-13. This molecule candidate exhibits more pronounced effects on viability inhibition (IC50 = 0.45 μM) and more significant m6A level reduction in cancer cells than its non-PRTOAC parent compounds. By incorporating the indole-nicotinamide chemotype as the METTL3-binding recruiter, this PROTAC is structurally distinct from recently published METTL3 PROTACs, expanding the design options for future METTL3 degrader development.
  • Item type: Item , ZeitschriftenaufsatzAccess status: Open Access ,
    Elucidating substituent effects in magnetic properties of redox active cobalt complexes and testing them as potential catalysts for HER
    (2025) Sundaresan, Sriram; Müller, Julia; Carrella, Luca M.; Rentschler, Eva
    We describe the synthesis of three cobalt complexes, C1–C3, featuring redox-active catechol ligands and a tetradentate salen ligand (Lsal). Structural characterization using single-crystal X-ray diffraction at 120 K, along with UV-vis, infrared spectroscopy, and SQUID magnetometry, provided detailed insights into their electronic and geometric properties. Magnetic measurements revealed that the two tetrahalogenated catechol complexes (C1 and C2) remain diamagnetic up to 400 K, whereas the complex with 3,5-ditert butyl catechol (C3) shows radical characteristics and stays in semiquinone form strongly coupled with a Co(III) centre. This radical behaviour was further confirmed by EPR spectroscopy in MeCN solution at room temperature. Cyclic voltammetry studies demonstrated the influence of catechol substituents on the electronic properties of these complexes, as reflected in shifts in oxidation potential. Preliminary investigations into their electrocatalytic activity for hydrogen production indicate that none of the complexes function effectively as catalysts under the tested conditions.