Biotin-PEG4-NHS ester

Monoclonal antibodies elicited to haptens that are analogs of the transition state for hydrolysis of carboxylic esters behaved as enzymic catalysts with the appropriate substrates. These substrates are distinguished by the structural congruence of both hydrolysis products with haptenic fragments. The haptens were potent inhibitors of this esterolytic activity, in agreement with their classification as transition state analogs. Mechanisms are proposed to account for the different chemical behavior of these antibodies with two types of ester substrates. The generation of an artificial enzyme through transition state stabilization by antibodies was thus demonstrated. These studies indicate a potentially general approach to catalyst design.

Biodegradable nonionic sugar esters-based surfactants have been gaining more and more attention in recent years due to their chemical plasticity that enables the various applications of these molecules. In this review, various synthesis methods and biotechnological implications of lactose esters (LEs) uses are considered. Several chemical and enzymatic approaches are described for the synthesis of LEs, together with their applications, i.e. function in detergents formulation and as additives that not only stabilize food products but also protect food from undesired microbial contamination. Further, this article discusses medical applications of LEs in cancer treatment, especially their uses as biosensors, halogenated anticancer drugs, and photosensitizing agents for photodynamic therapy of cancer and photodynamic inactivation of microorganisms.

"Dance reaction" on the aromatic ring is a powerful method in organic chemistry to translocate functional groups on arene scaffolds. Notably, dance reactions of halides and pseudohalides offer a unique platform for the divergent synthesis of substituted (hetero)aromatic compounds when combined with transition-metal-catalyzed coupling reactions. Herein, we report a tandem reaction of ester dance and decarbonylative coupling enabled by palladium catalysis. In this reaction, 1,2-translocation of the ester moiety on the aromatic ring is followed by decarbonylative coupling with nucleophiles to enable the installation of a variety of nucleophiles at the position adjacent to the ester in the starting material.