In this contribution, the preparation of hierarchically structured ETS-10-based catalysts exhibiting notably higher activity in the conversion of triolein with methanol compared to microporous titanosilicate is presented. Triolein, together with its unsaturated analog trilinolein, represent the most prevalent triglycerides in oils. The introduction of mesopores by post-synthetic treatment with hydrogen peroxide and a subsequent calcination step results in the generation of an additional active surface with Brønsted basic sites becoming accessible for triolein and enhancing the rate of transesterification. The resulting catalyst exhibits a comparable triolein conversion (≈73%) after 4 h of reaction to CaO (≈76%), which is reportedly known to be highly active in the transesterification of triglycerides. In addition, while CaO showed a maximum conversion of 83% after 24 h, the ETS-10-based catalyst reached 100% after 8 h, revealing its higher stability compared to CaO. The following characteristics of the catalysts were experimentally addressed – crystal structure (X-ray diffraction, transmission electron microscopy), crystal shape and size (scanning electron microscopy, laser diffraction), textural properties (N₂ sorption, Hg porosimetry), presence of hydroxyl groups and active sites (temperature-programmed desorption of NH₃ and CO₂, ²⁹Si magic angle spinning nuclear magnetic resonance (NMR)), mesopore accessibility and diffusion coefficient of adsorbed triolein (pulsed field gradient NMR), pore interconnectivity (variable temperature and exchange spectroscopy experiments using hyperpolarized ¹²⁹Xe NMR) and oxidation state of Ti atoms (electron paramagnetic resonance). The obtained results enabled the detailed understanding of the impact of the post-synthetic treatment applied to the ETS-10 titanosilicate with respect to the catalytic activity in the heterogeneously catalyzed transesterification of triglycerides.

When impregnated with manganiferous precursors, γ-Al₂O₃ may be converted into α-Al₂O₃ under relatively mild and energy-saving conditions. In this work, a manganese assisted conversion to corundum at temperatures as low as 800 °C is investigated. To observe the alumina phase transition, XRD and solid-state ²⁷Al-MAS-NMR are applied. By post-synthetical treatment in concentrated HCl, residual manganese is removed up to 3 wt.-%. Thereby, α-Al₂O₃ with a high specific surface area of 56 m² g⁻¹ is obtained after complete conversion. Just as for transition alumina, thermal stability is an important issue for corundum. Long-term stability tests were performed at 750 °C for 7 days. Although highly porous corundum was synthesized, the porosity decreased with time at common process temperatures.

²⁹Si MAS NMR, Raman spectroscopy and hyperpolarized¹²⁹Xe NMR reveal the post-synthetic modification of porous glass. The grafting, the effect on the pore structure and the identity of the immobilized species are investigated.

Rhodamine 110 (R110) peptide conjugates are widely used fluorogenic substrates in proteolytic assays; however, their inherent symmetry results in two identical hydrolysis sites, complicating their application as well-defined substrates. Here, we report a preparative enzymatic strategy for the desymmetrization of the symmetric derivative (Acetyl-Leu-Pro-Lys)₂-R110 using the bovine trypsin variant D189S. Due to pronounced differences in the rates of the two sequential hydrolysis steps, a mono-substituted intermediate accumulates under controlled reaction conditions. On a preparative scale, Acetyl-Leu-Pro-Lys-R110 was generated by partial hydrolysis and isolated by preparative HPLC in 28.8% yield and 95.8% purity. The structure of the asymmetric product was fully characterized by NMR and high-resolution mass spectrometry. This work demonstrates that selective enzymatic hydrolysis provides a simple and effective preparative route to asymmetric Rhodamine 110 derivatives, offering a practical alternative to conventional multistep synthetic approaches and enabling improved substrate design for kinetic studies.

Sächsische Regentinnen des 12. Jahrhunderts – Kaiserin Richenza und Herzogin Gertrud von Sachsen und Bayern was published in Regentinnen und andere Stellvertreterfiguren on page 53.