Preparation of a chiral hyperbranched polymer based on cinchona alkaloids and investigation of its catalytic activity in asymmetric reactions.

Cinchona alkaloid-derived sulfonamides and ester dimers containing chiral hyperbranched polymers have been successfully synthesized and applied as catalysts in asymmetric reactions. Several hyperbranched polymers derived from cinchona alkaloids, incorporating sulfonamides and esters, were synthesized through Mizoroki-Heck coupling polymerization. These polymers were subsequently applied in enantioselective Michael addition reactions.

Synthesis of cinchona urea polymers using Yamamoto coupling and their application to asymmetric reaction.

Cinchona urea compounds having 3,5-diiodophenyl moieties were subjected to Yamamoto coupling polymerization to afford the chiral urea polymers. These polymers showed high activities as heterogeneous catalysts in asymmetric Michael reactions comparable with those of the corresponding monomeric catalyst in solution systems. Furthermore, the polymeric catalysts are easily recovered from their reaction mixtures due to their insolubility and can be reused several times without loss of catalytic activity.

Simple production of resilin-like protein hydrogels using the Brevibacillus secretory expression system and column-free purification.

Resilin, an insect structural protein, has excellent flexibility, photocrosslinking properties, and temperature responsiveness. Recombinant resilin-like proteins (RLPs) can be fabricated into three-dimensional (3D) structures for use as cell culture substrates and highly elastic materials. A simplified, high-yielding production process for RLPs is required for their widespread application.

Autonomous Sequences in Myoglobin Emerging from X-ray Structure of Holomyoglobin.

The proposed continuous folding structure units are fundamental to analyze protein structure. Here, we could elucidate for the first time two types of hydrophobic core networks in apomyoglobin using continuous folding structure units. In myoglobin, two autonomous sequences emerged clearly.

Study on the performance of methyl methacrylate polymerization: Comparison of partially oxidized tri-n-butylborane and benzoyl peroxide with aromatic tertiary amines.

In this study, we examined the polymerization performance of methyl methacrylate (MMA) initiated with partially oxidized tri-nbutylborane (TBBO) compared to that initiated with benzoyl peroxide and aromatic tertiary amine (BPO/amine) system. In the bulk polymerization of MMA at 37°C, conversion initiated with TBBO after 3 h was nearly quantitative, whereas the conversion with the BPO/amine system was low (~20%). The number-averaged and weight-averaged molecular weight of the TBBO-initiated polymer was more than twice as high as that of the BPO/amine-initiated polymer.