10.1021/ja00365a087
The research includes three distinct studies. The first study investigates the biosynthetic pathway of streptonigrin, utilizing [U - L3C6] glucose to elucidate the complex process, with erythrose-4-phosphate and 4-aminoanthranilic acid being key intermediates. The second study details the synthesis of a helical ferrocene. It involves creating a helical structure with cyclopentadienyl rings, using 2,7-dihydroxynaphthalene, vinyl ketone cyclization, and photocyclization. The final product is obtained by reacting the lithium salt of the helical structure with FeCl?. The third study examines the catalytic hydrolysis of esters of p-nitrophenol bound by amylose in a Me?SO-H?O mixed-solvent system, focusing on the conformational changes and rate accelerations in this unique environment.
10.1002/chem.200390110
The study focuses on the development and application of fluorogenic stereochemical probes for transaldolases, enzymes that catalyze the transfer of dihydroxyacetone between sugar phosphates. The researchers synthesized two probes, 6-O-coumarinyl-fructose (1) and its 5-deoxy derivative (2), which are designed to measure the stereoselectivity of transaldolases. These probes work by undergoing a retro-aldolization reaction catalyzed by transaldolases, producing a primary product that further reacts to release a strongly fluorescent product, umbelliferone, upon elimination in the presence of bovine serum albumin (BSA). The study also involved the synthesis of a stereoisomer related to tagatose (3), which serves as a control to assess the stereoselectivity of the enzymes. The purpose of these chemicals is to provide a fluorogenic assay system for transaldolases, suitable for high-throughput screening of enzyme libraries, particularly for directed evolution experiments aiming to alter enzyme stereoselectivity. The study includes the use of various other chemicals, such as erythrose 4-phosphate as a natural acceptor to shift the reaction equilibrium, and a range of solvents and reagents in the synthesis and purification processes.