pH-Degradable Polymers as Impermanent Antimicrobial Agents for Environmental Sustainability.

Globally, over 100,000 tons of antibiotics are consumed each year with a significant proportion discharged into the environment. As antibiotic usage continues to rise, there is a pressing need to reduce antibiotic pollution by developing antimicrobials whose activity can be switched off after the material has served its intended purpose. We have reported a series of imidazolium polymers incorporating pH-degradable linkers.

Soft Surface Nanostructure with Semi-Free Polyionic Components for Sustainable Antimicrobial Plastic.

Surface antimicrobial materials are of interest as they can combat the critical threat of microbial contamination without contributing to issues of environmental contamination and the development drug resistance. Most nanostructured surfaces are prepared by post fabrication modifications and actively release antimicrobial agents. These properties limit the potential applications of nanostructured materials on flexible surfaces.

Broad spectrum antimicrobial PDMS-based biomaterial for catheter fabrication.

Background: In addition to the widespread use of antibiotics in healthcare settings, the current COVID-19 pandemic has escalated the emergence of antibiotic resistance. Nosocomial infections among hospitalized patients is a leading site for such resistant microbial colonization due to prolonged use of invasive devices and antibiotics in therapies. Invasive medical devices, especially catheters, are prone to infections that could accelerate the development of resistant microbes.

Rational Design of Gram-Specific Antimicrobial Imidazolium Tetramers To Combat MRSA.

Antimicrobial resistance poses an increasingly serious global health threat. Hence, new antimicrobials with low propensity toward inducing resistance in bacteria are being developed to combat this threat. In this work, a series of imidazolium tetramers have been synthesized by modulating the linkers between imidazoliums or the length of the end groups within the structures of oligomers in order to optimize the activity, selectivity, and biocompatibility of the compounds.

pH-Degradable imidazolium oligomers as antimicrobial materials with tuneable loss of activity.

Antimicrobial resistance (AMR) has become a global public health threat. One of the major causes of AMR development is the accumulation of low levels of antimicrobials in the environment. To tackle this problem, novel antimicrobial agents that do not leave active residues after treatment are needed.

NHC-Ag/Pd-Catalyzed Reductive Carboxylation of Terminal Alkynes with CO and H : A Combined Experimental and Computational Study for Fine-Tuned Selectivity.

Reductive carboxylation of terminal alkynes utilizing CO and H as reactants is an interesting and challenging transformation. Theoretical calculations indicated it would be kinetically possible to obtain cinnamic acid, the reductive carboxylation product, from phenylacetylene in a CO /H system with an N-heterocyclic carbene (NHC)-supported Ag/Pd bimetallic catalysts through competitive carboxylation/hydrogenation cascade reactions in one step. These calculations were verified experimentally with a poly-NHC-supported Ag/Pd catalyst.

Direct Amidation of N-Boc- and N-Cbz-Protected Amines via Rhodium-Catalyzed Coupling of Arylboroxines and Carbamates.

N-Boc- and N-Cbz-protected amines are directly converted into amides by a novel rhodium-catalyzed coupling of arylboroxines and carbamates, replacing the traditional two-step deprotection-condensation sequence. Both protected anilines and aliphatic amines are efficiently transformed into a wide variety of secondary benzamides, including sterically hindered and electron-deficient amides, as well as in the presence of acid-labile and reducible functional groups.

Synergistic Carbon Dioxide Capture and Conversion in Porous Materials.

Global climate change and excessive CO2 emissions have caused widespread public concern in recent years. Tremendous efforts have been made towards CO2 capture and conversion. This has led to the development of numerous porous materials as CO2 capture sorbents.

Synthesis of cyclic alkenylsiloxanes by semihydrogenation: a stereospecific route to (Z)-alkenyl polyenes.

Cyclic alkenylsiloxanes were synthesized by semihydrogenation of alkynylsilanes-a reaction previously plagued by poor stereoselectivity. The silanes, which can be synthesized on multigram scale, undergo Hiyama-Denmark coupling to give (Z)-alkenyl polyene motifs found in bioactive natural products. The ring size of the silane is crucial: five-membered cyclic siloxanes also couple under fluoride-free conditions, whilst their six-membered homologues do not, enabling orthogonality within this structural motif.

One-step preparation of functionalized (E)-vinylsilanes from aldehydes.

Functionalized (E)-vinylsilanes have been prepared in one step from a wide range of aldehydes, via a chromium(II)-mediated olefination with novel dihalomethylsilane reagents, in moderate to excellent yields and with excellent stereoselectivity.

Structural insights into the design of small molecule inhibitors that selectively antagonize Mcl-1.

The screening of a small focused library of rhodanine derivatives as inhibitors of Bcl-2 proteins led to the discovery of two structurally related compounds with different binding profiles against the Bcl-XL and the Mcl-1 proteins. Subsequent NMR studies with mutant proteins and in silico docking studies provide a possible rationale for the observed specificity.