Preparation of Metal-Immobilized Methacrylate-Based Monolithic Columns for Flow-Through Cross-Coupling Reactions

Abstract

With the aim of developing efficient flow-through microreactors for high-throughput organic synthesis, in this work, microreactors were fabricated by chemically immobilizing palladium-, nickel-, iron-, and copper-based catalysts onto ligand-modified poly(glycidyl methacrylate-co-ethylene dimethacrylate) [poly(GMA-co-EDMA)] monoliths, which were prepared inside a silicosteel tubing (10 cm long with an inner diameter of 1.0 mm) and modified with several ligands including 5-amino-1,10-phenanthroline (APHEN), iminodiacetic acid (IDA), and iminodimethyl phosphonic acid (IDP). The performance of the resulting microreactors in Suzuki−Miyaura cross-coupling reactions was evaluated, finding that the poly(GMA-co-EDMA) monolith chemically modified with 5-amino-1,10-phenanthroline as a binding site for the palladium catalyst provided an excellent flow-through performance, enabling highly efficient and rapid reactions with high product yields. Moreover, this monolithic microreactor maintained its good activity and efficiency during prolonged use.

Identification of post-translational modifications of milk and whey proteins with different structures

“…Higher sequence coverage results were obtained for the smaller of the studied proteins (18 307.55 Da) βLG (oxidation and phosphorylation, respectively -49% and 0% (classical digestion in solution), 60% and 79% (classical digestion in solution and ZipTip pipette tips), 65% and 0% (µ-IMER), 80% and 89% (µ-IMER and ZipTip pipette tips). However, taking into account the results of βLG phosphorylation, which itself is not a phosphorylated protein and phosphorylation products should not occur (a commercial protein was used), the use of ZipTip was successful for the bigger protein (23,885.90 Da) βCN (oxidation and phosphorylation, respectively -20% and 0% (classical digestion in solution), 26% and 27% (classical digestion in solution and ZipTip pipette tips), 33% and 30% (µ-IMER), 41% and 33% (µ-IMER and ZipTip pipette tips). As the post-translational modi cations affect the structure and biological functions of proteins and peptides by modifying the side chains of amino acids after their biosynthesis the knowledge on their presence might be of particular importance in preparation of functional food preparations or diet additives like protein hydrolysates.…”

“…To the best of our knowledge, there are many studies in which monolith-based enzyme microreactors are obtained to exploit both monolithic bed advantages or digestion performance to detect and identi y digestion products by mass spectrometry [22], [23]. Villegas et al used the IMER-CE-MS method for enzymatic digestion, separation, and on-line characterization of proteins [24].…”

“…The more commonly used bottom-up strategy involves the classical tryptic in-gel digestion or enzymatic digestion of proteins into peptides, which are then identi ed on the mass spectrometer. While numerous studies have focused on monolith-based enzyme microreactors for the detection and identi cation of digestion products using mass spectrometry, to our knowledge, no literature has reported a comparison between the classical in-solution digestion method and μ-IMER, in conjunction with the use of ZipTips pipette tips for peptide enrichment [12], [13].…”

Immobilized enzyme microreactors for analysis of tryptic peptides in β-casein and β-lactoglobulin

“…Subsequent MS and MS/MS analysis of peptides will increase sensitivity and specificity, reveal the identity of proteins, and allow specific assignment of modifications sites 15 . While numerous studies have focused on monolith-based enzyme microreactors for the detection and identification of digestion products using mass spectrometry, to our knowledge, no literature has reported a comparison between the classical in-gel digestion method and μ-IMER, in conjunction with the use of ZipTips for peptide enrichment 16 , 17 .…”

Removal of Toxic Metal Ions Using Poly(BuMA–co–EDMA) Modified with C-Tetra(nonyl)calix[4]resorcinarene

“…Taking the above into account, the modification of polymeric materials by means of organic ligands is efficient if there is a large surface area for the chemical or physical modification process. Polymeric materials with these characteristics are known as monoliths [ 7 , 8 , 9 ], which are polymers or copolymers obtained through a polymerization processes in the presence of a porogenic agent [ 10 , 11 ]; in this way, a highly porous material can be obtained that confers a large surface area to the polymer, which is convenient for the modification processes and also for the adsorption processes of heavy metal cations or other types of substances.…”