Efficient production of γ-aminobutyric acid by glutamate decarboxylase immobilized on an amphiphilic organic-inorganic hybrid porous material.

A novel organic-inorganic hybrid porous material (KCS-2), containing both lipophilic and hydrophilic nanospaces to mimic a lipid bilayer, was utilized as an immobilization support and reaction accelerator for glutamate decarboxylase (GADβ). Upon evaluation of the adsorption of GADβ on KCS-2, the amount of immobilization was found to be approximately four times higher than that on non-porous silica, and a comparable adsorbability to mesoporous silica was observed. Following γ-aminobutyric acid (GABA) production by the decarboxylation of l-glutamic acid using these immobilized enzymes, the enzymatic activity of the GADβ-KCS-2 composite was found to be significantly higher than that of the free enzyme.

Enzyme Immobilization in Mesoporous Silica for Enhancement of Thermostability.

Direct enzyme immobilization by encapsulation in the pores of mesoporous silica particles enhances protein thermal and chemical stability. In this study, we investigated the effect of pore size on the thermostability and catalytic activity of Escherichia coli glutaminase YbaS encapsulated under high temperature conditions in two SBA-type mesoporous silicas: SBA5.4 and SBA10.

Three-Component, Diastereoselective Prins-Ritter Reaction for cis-Fused 4-Amidotetrahydropyrans toward a Precursor for Possible Neuronal Receptor Ligands.

Here, we report an unprecedented, highly diastereoselective Prins-Ritter reaction of aldehydes, homoallylic alcohols, and nitriles in a three-component coupling reaction for the synthesis of tetra-cis-substituted 4-amidotetrahydropyrans. In this study, the reaction was not only applied for carbohydrate-based heterobicycles but also for more complex heterotricycles, showing acceptable levels of conversion yield (42-97% BRSM) and exclusive diastereoselectivity. Furthermore, the latter heterotricycles were converted to nine analogues of our neuronal receptor ligands IKM-159 and MC-27.

Structure-activity relationships of IKM-159: Diverted synthesis and biological evaluation of a series of C5-oxy analogs.

Ligands for neuronal receptors are important for understanding the biological functions as well as for treatment of neuronal diseases associated with. Here, we report diverted synthesis and biological evaluation of four C-ring analogs of IKM-159, a subtype-selective inhibitor for (S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA)-type ionotropic glutamate receptor. Starting from iodinated 7-oxanorbornene 7, those analogs 3-6 were successfully synthesized in 7.