A Review on the Antimicrobial Activity of Schiff Bases: Data Collection and Recent Studies

Abstract

Schiff bases (SBs) have extensive applications in different fields such as analytical, inorganic and organic chemistry. They are used as dyes, catalysts, polymer stabilizers, luminescence chemosensors, catalyzers in the fixation of CO2 biolubricant additives and have been suggested for solar energy applications as well. Further, a wide range of pharmacological and biological applications, such as antimalarial, antiproliferative, analgesic, anti-inflammatory, antiviral, antipyretic, antibacterial and antifungal uses, emphasize the need for SB synthesis. Several SBs conjugated with chitosan have been studied in order to enhance the antibacterial activity of chitosan. Moreover, the use of the nanoparticles of SBs may improve their antimicrobial effects. Herein, we provide an analytical overview of the antibacterial and antifungal properties of SBs and chitosan-based SBs as well as SBs-functionalized nanoparticles. The most relevant and recent literature was reviewed for this purpose.

Simultaneous Release of Silver Ions and 10–Undecenoic Acid from Silver Iron–Oxide Nanoparticles Impregnated Membranes

“…At the studied pH values, the release of 10-undecenoic acid follows the shape of the curves for silver ions, but its concentration is lower (Figure 10b). However, the 10-undecenoic concentration slowly exceeds the limit of its solubility in pure water, thus contributing to the fungicidal effect of the studied system [63]. The reason for which the compounds derived from 10-undecenoic acid allow the release of smaller amounts of silver ions (equilibria (7) and ( 8)) can be understood in this way: they have a single center of interaction organic compound-silver ions, compared to 10-undecenoic acid which may have two such centers of interaction (equilibria (3) and ( 4)): The test of the polysulfone-10-undecenoic acid-oxide nanoparticles system containing 1.63% silver for the simultaneous controlled release of silver ions and 10-undecenoic acid shows that at extreme pH values, the concentration of silver ions covering the bactericidal and cytotoxic requirements is obtained quickly, and the concentration level after 7 days of contact is slightly higher than at a pH close to neutral pH (Figures 5 and 10a).…”

“…At the studied pH values, the release of 10-undecenoic acid follows the shape of the curves for silver ions, but its concentration is lower (Figure 10b). However, the 10-undecenoic concentration slowly exceeds the limit of its solubility in pure water, thus contributing to the fungicidal effect of the studied system [63]. The reason for which the compounds derived from 10-undecenoic acid allow the release of smaller amounts of silver ions (equilibria ( 7) and ( 8)) can be understood in this way: they have a single center of interaction organic compound-silver ions, compared to 10-undecenoic acid which may have two such centers of interaction (equilibria (3) and ( 4)):…”

COVID-19 at a Glance: An Up-to-Date Overview on Variants, Drug Design and Therapies

“…CVL218 was able to inhibit SARS-CoV-2 replication without exhibiting any obvious cytopathic effects; moreover, CVL218 can interact with the nucleocapsid protein of SARS-CoV-2 and suppress the LPS-induced production of several inflammatory cytokines that are highly relevant to the prevention of the immunopathology induced by SARS-CoV-2 infection [ 132 ]. Several other compounds, endowed with different biological activities, have been proposed for repositioning [ 133 ], such as ivermectin (IVM), an FDA-approved antiparasitic drug for onchocerciasis and strongyloidiasis [ 134 ], fibrates, diarylureas [ 135 , 136 ], Schiff bases [ 137 , 138 , 139 ] and transition metal complexes [ 140 , 141 ]. Moreover, a recent article indicated the use of repositioning microbial biotechnology for studies against COVID-19, particularly for flavonoids.…”

Triclosan: A Small Molecule with Controversial Roles

“…TCS activity in periodontitis is related to the activation of human periodontal ligament fibroblasts that are induced by lipopolysaccharide from Porphyromonas gingivalis [ 98 ]. Recently, the link between TCS and chitosan, a natural polymer that may act as a drug delivery agent and exerts antibacterial and anti-inflammatory activities [ 99 ], has been investigated in the prevention and/or treatment of inflammation in periodontal diseases. Chitosan-TCS particles were able to modulate the inflammatory response in gingival fibroblasts [ 100 ].…”