Synthesis of Adamantane-Based Trimeric Benzoboroxoles

Mechanochemical synthesis of antifungal bis(benzoxaboroles)

Several piperazine bis(benzoxaboroles) have been obtained both in solution as well as in the solid state. The environmentally friendly mechanochemical approach – hitherto not applied for the preparation of benzoxaboroles – was particularly beneficial in the case of two products afforded in low yields in solution. The in vitro studies showed high potential of the studied bis(fluorobenzoxaboroles) as antifungal agents, highlighting also the influence of the fluorine substituent position on their microbiological activity. The highest activity against A. niger, A. terreus, P. ochrochloron, C. tenuis and C. albicans was displayed by the analogue of the known benzoxaborole antifungal drug Kerydin® (Tavaborole).

Several piperazine bis(benzoxaboroles) have been obtained mechanochemically – two of them have been shown to display high antifungal activity.

Improving cellular uptake of therapeutic entities through interaction with components of cell membrane

Efficient cellular delivery of biologically active molecules is one of the key factors that affect the discovery and development of novel drugs. The plasma membrane is the first barrier that prevents direct translocation of chemic entities, and thus obstructs their efficient intracellular delivery. Generally, hydrophilic small molecule drugs are poor permeability that reduce bioavailability and thus limit the clinic application. The cellular uptake of macromolecules and drug carriers is very inefficient without external assistance. Therefore, it is desirable to develop potent delivery systems for achieving effective intracellular delivery of chemic entities. Apart from of the types of delivery strategies, the composition of the cell membrane is critical for delivery efficiency due to the fact that cellular uptake is affected by the interaction between the chemical entity and the plasma membrane. In this review, we aimed to develop a profound understanding of the interactions between delivery systems and components of the plasma membrane. For the purpose, we attempt to present a broad overview of what delivery systems can be used to enhance the intracellular delivery of poorly permeable chemic entities, and how various delivery strategies are applied according to the components of plasma membrane.

Bis-benzoxaboroles: Design, Synthesis, and Biological Evaluation as Carbonic Anhydrase Inhibitors

The synthesis, characterization, and biological evaluation of a series of compounds incorporating two or three benzoxaborole moieties is reported. Three different synthetic strategies were used to explore within this series as much chemical space as possible, all starting from the 6-aminobenzoxaborole reagent: amide coupling, imine bond formation, and squarate coupling. Eleven new compounds were isolated in pure form, and single crystals were obtained for two of them. These compounds were then evaluated as carbonic anhydrase inhibitors against the cytosolic hCA I and II and the transmembrane hCA IV, IX, and XII isoforms. While the benzoxaborole scaffold has been recently introduced as a new chemotype for carbonic anhydrase inhibition, these new multivalent derivatives exhibited superior inhibitory activity against the tumor-associated isoform hCA IX. In particular, compared to monovalent 6-aminobenzoxaborole (K _I = 813 nM) and 6-carboxybenzoxaborole (K _I = 400 nM), derivative 2h characterized by a glutamic acid structural core and two benzoxaborole moieties was found to be more potent (K _I = 64 nM) and more selective over human hCA II.

Exploring Rigid and Flexible Core Trivalent Sialosides for Influenza Virus Inhibition

Herein, the chemical synthesis and binding analysis of functionalizable rigid and flexible core trivalent sialosides bearing oligoethylene glycol (OEG) spacers interacting with spike proteins of influenza A virus (IAV) X31 is described. Although the flexible Tris-based trivalent sialosides achieved micromolar binding constants, a trivalent binder based on a rigid adamantane core dominated flexible tripodal compounds with micromolar binding and hemagglutination inhibition constants. Simulation studies indicated increased conformational penalties for long OEG spacers. Using a systematic approach with molecular modeling and simulations as well as biophysical analysis, these findings emphasize on the importance of the scaffold rigidity and the challenges associated with the spacer length optimization.

A multinuclear NMR perspective on the complexation between bisboronic acids and bisbenzoxaboroles with cis-diols

A new way of using solution NMR (especially ¹⁹F NMR) to study organoboron molecule/cis-diol equilibria is presented.

Polycationic adamantane-based dendrons form nanorods in complex with plasmid DNA

Different HYDRAmers are synthesized and complexed to a model plasmid DNA. Appropriate chemical modifications can improve efficiently the complexation to get HYDRAplexes, in form of long nanorods, with very good DNA binding and protecting properties.

The unique chemistry of benzoxaboroles: current and emerging applications in biotechnology and therapeutic treatments

Benzoxaboroles have garnered much attention in recent years due to their diverse applications in bio-sensing technology, material science, and therapeutic intervention. Part of the reason arises from the benzoxaboroles' unique chemical properties, especially in comparison to their acyclic boronic acid counterparts. Furthermore, the low bio-toxicity combined with the high target specificity associated with benzoxaboroles make them very attractive as therapeutic agents. Herein, we provide an updated summary on the current knowledge of the fundamental chemical reactivity of benzoxaboroles, followed by highlighting their major applications reported to date.