Chemoselective synthesis of aryl carboxamido sulfonic acid derivatives

Chemoselective Reactions of Functionalized Sulfonyl Halides

Chemoselective transformations of functionalized sulfonyl fluorides and chlorides are surveyed comprehensively. It is shown that sulfonyl fluorides provide an excellent selectivity control in their reactions. Thus, numerous conditions are tolerated by the SO2 F group - from amide and ester formation to directed ortho-lithiation and transition-metal-catalyzed cross-couplings. Meanwhile, sulfur (VI) fluoride exchange (SuFEx) is also compatible with numerous functional groups, thus confirming its title of "another click reaction". On the contrary, with a few exceptions, most transformations of functionalized sulfonyl chlorides typically occur at the SO2 Cl moiety.

Design, Synthesis, and Biological Evaluation of Novel Thioureidobenzamide (TBA) Derivatives as HBV Capsid Assembly Modulators

Hepatitis B virus (HBV) capsid assembly modulators (CAMs) represent a promising therapeutic approach for the treatment of HBV infection. In this study, we designed and synthesized five series of benzamide derivatives based on a multisite-binding strategy at the tolerant region and diversity modification in the solvent-exposed region. Among them, thioureidobenzamide compound 17i exhibited significantly increased anti-HBV activity in HepAD38 (EC50 = 0.012 μM) and HBV-infected HLCZ01 cells (EC50 = 0.033 μM). Moreover, 17i displayed a better inhibitory effect on the assembly of HBV capsid protein compared with NVR 3-778 and a inhibitory effect similar to the clinical drug GLS4. In addition, 17i showed moderate metabolic stability in human microsomes, had excellent oral bioavailability in Sprague-Dawley (SD) rats, and inhibited HBV replication in the HBV carrier mice model, which could be considered as a promising candidate drug for further development.

One-pot synthesis of glycosyl phenylthiosulfonates from sulfinate, S and glycosyl bromides

Glycosyl phenylthiosulfonates are reagents which are valuable for the S-glycosylation decoration of organic compounds and proteins. Here, one-pot multiple-component synthesis of glycosyl phenylthiosulfonates from sulfinate, sulfur powder and glycosyl bromides is reported. The reactions afford glycosyl phenylthiosulfonates in good yields under mild conditions. Further application and exploration of glycosyl phenylthiosulfonates are still on underway in our group.

Glycan-Directed Grafting-from Polymerization of Immunoglobulin G: Site-Selectively Modified IgG-Polymer Conjugates with Preserved Biological Activity

Antibody and related antibody drugs for the treatment of malignancies have led to progress in targeted cancer therapy. Preparation of diverse antibody conjugates is critical for preclinical and clinical applications. However, precise control in tagging molecules at specific locations on antibodies is essential to preserve their native function. In this study, a synthetic boronic acid (BA)-tosyl initiator was used to trigger a glycan-directed modification of IgGs, and the obtained IgG macroinitiators allowed a growth of the poly N-isopropylacrylamide (PNIPAAm) chains specifically at Fc-domains. Therefore, the PNIPAAm chains are located away from the critical antigen-binding domains (Fab), which could reasonably prevent the loss of biological activity after the attachment of polymer chains. According to the proposed strategy, a site-selectively modified anticoncanavalin A (Con A) antibody-PNIPAAm conjugate showed 6-times higher efficiency in the binding of targeted Con A antigen to a randomly conjugated anti-Con A antibody-PNIPAAm conjugate. In this study, we developed the first chemical strategy for the site-specific preparation of IgG-polymer conjugates with conserved biological activity as well as intact glycan structures.

Synthesis and Evaluation of N-Phenyl-3-sulfamoyl-benzamide Derivatives as Capsid Assembly Modulators Inhibiting Hepatitis B Virus (HBV)

Small molecule induced hepatitis B virus (HBV) capsid assembly modulation is considered an attractive approach for new antiviral therapies against HBV. Here we describe efforts toward the discovery of a HBV capsid assembly modulator in a hit-to-lead optimization, resulting in JNJ-632, a tool compound used to further profile the mode of action. Administration of JNJ-632 (54) in HBV genotype D infected chimeric mice resulted in a 2.77 log reduction of the HBV DNA viral load.

A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

For the synthesis of m-sulfamoylbenzamide analogues, small molecules which are known for their bioactivity, a chemoselective procedure has been developed starting from m-(chlorosulfonyl)benzoyl chloride. Although a chemoselective process in batch was already reported, a continuous-flow process reveals an increased selectivity at higher temperatures and without catalysts. In total, 15 analogues were synthesized, using similar conditions, with yields ranging between 65 and 99%. This is the first automated and chemoselective synthesis of m-sulfamoylbenzamide analogues.

Traceless labeling of glycoproteins and its application to the study of glycoprotein-protein interactions

A new chemical method for the traceless labeling of glycoproteins with synthetic boronic acid (BA)-tosyl probes was successfully developed. The BA moiety acts as an affinity head to direct the formation of a cyclic boronate diester with the diol groups of glycans. Following this step, the electrophilic tosyl group is displaced by an SN2 reaction with a nucleophilic residue of the boronated glycoprotein, and finally, a reporter group is tagged onto the glycoprotein via an ether linkage. In the presence of polyols, a competition reaction recovers the native glycan of the tagged glycoprotein, conserving its biological significance. The BA-tosyl probes were used successfully for the specific labeling of glycosylated fetuins in a mixed protein pool and from crude Escherichia coli (E. coli) lysate. Further, a BA-tosyl-functionalized glass slide was used to fabricate glycoprotein microarrays with highly conserved glycans. By interacting with various lectins (carbohydrate-binding proteins), such as Concanavalin A (Con A) and wheat germ agglutinin (WGA), the types of carbohydrates and specific linkages of glycoproteins (α or β) could be systematically monitored. It is believed that the newly developed method will greatly accelerate the understanding of glycoproteins.