New O-Aryl-Carbamoyl-Oxymino-Fluorene Derivatives with MI-Crobicidal and Antibiofilm Activity Enhanced by Combination with Iron Oxide Nanoparticles

Abstract

Antimicrobial resistance is one of the major public health threats at the global level, urging the search for new antimicrobial molecules. The fluorene nucleus is a component of different bioactive compounds, exhibiting diverse pharmacological actions. The present work describes the synthesis, chemical structure elucidation, and bioactivity of new O-aryl-carbamoyl-oxymino-fluorene derivatives and the contribution of iron oxide nanoparticles to enhance the desired biological activity. The antimicrobial activity assessed against three bacterial and fungal strains, in suspension and biofilm growth state, using a quantitative assay, revealed that the nature of substituents on the aryl moiety are determinant for both the spectrum and intensity of the inhibitory effect. The electron-withdrawing inductive effect of chlorine atoms enhanced the activity against planktonic and adhered Staphylococcus aureus, while the +I effect of the methyl group enhanced the anti-fungal activity against Candida albicans strain. The magnetite nanoparticles have substantially improved the antimicrobial activity of the new compounds against planktonic microorganisms. The obtained compounds, as well as the magnetic core@shell nanostructures loaded with these compounds have a promising potential for the development of novel antimicrobial strategies.

Insights into the Microbicidal, Antibiofilm, Antioxidant and Toxicity Profile of New O-Aryl-Carbamoyl-Oxymino-Fluorene Derivatives

“…Thus, there is an acute need to find antibiotics with original structures, having new microbial targets. Taking into account that fluorine is found in diverse pharmacologically active compounds with antimalarial (lumefantrine), antiarrhythmic (indecainide), muscle relaxant (hexafluronium bromide or antiviral (tilorone) activity as well as the pharmacological activities of carbamoyl and oximinic pharmacophore groups, we have combined these biologically active fragments into a single original molecule, to obtain new compounds of the class O-aryl-carbamoyl-oxymino-fluorene, previously characterized [ 17 ] ( Figure 4 ) and to evaluate their potential bactericidal, fungicidal and antibiofilm effects.…”

“…We have previously synthesized and characterized four new O-aryl-carbamoyl-oxymino-fluorene derivatives ( 1a – d ) ( Figure 1 ) [ 17 ].…”

“…In this context, the aim of this paper was to evaluate the antimicrobial features of new O-aryl-carbamoyl-oxymino-fluorene derivatives, previously reported for their inhibitory activity against Gram-positive (e.g., Bacillus anthracis , S. aureus , including methicillin resistant strains) and Gram-negative ( Escherichia coli , Proteus mirabilis , K. pneumoniae , P. aeruginosa , Burkholderiathailandensis and Francisella tularensis ) bacterial strains, mycobacteria, yeasts and molds [ 14 , 15 , 16 , 17 ]. The antioxidant activity of these compounds has been also evaluated, as it could represent an advantage for novel antimicrobial leads by decreasing the intensity and duration of the inflammatory response often accompanying the infectious process, thus avoiding their deleterious effects on the host tissues [ 18 ].…”

Continuous glucose monitoring devices: A brief presentation (Review)

“…The materials from which the coatings are made can be classified as follows: i) Natural such as alginate, chitin and chitosan; and ii) semisynthetic or synthetic derivatives; such as biodegradable polymers [poly(lactic-co-glycolic acid), polyethylene glycol, poly(2-hydroxyethyl methacrylate)] and polyvinyl alcohol ( 19 , 32 , 33 ). Novel nanostructures with antimicrobial activity and good potential for increasing biocompatibility are currently being investigated ( 34 ).…”

Visible Light‐Induced Synthesis of Fluorenes from α‐Biaryldiazoacetates

“…Employment of visible light to promote carbene transfer reactions of diazo compounds has gradually emerged due to its mildness, high efficiency, and environmentally benign characters. [11][12][13][14][15][16][17][18] On the other hand, fluorene is a high-value structural motif in both pharmaceuticals [19,20] and material science. [21,22] It appears in a wide range of therapeutic drugs, [19] as exemplified by 2,7-dichloro-7H-fluorene serving as the backbone of lumefantrine, an antimalarial medicine (Figure 1).…”