Wound healing and antimicrobial effect of active secondary metabolites in chitosan-based wound dressings: A review

Novel and Efficient Synthesis of Iminocoumarins via Copper-Catalyzed Multicomponent Reaction

Chitosan is obtained from alkaline deacetylation of chitin, and acetamide groups are transformed into primary amino groups during the deacetylation. The diverse biological activities of chitosan and its derivatives are extensively studied that allows to widening the application fields in various sectors especially in biomedical science. The biological properties of chitosan are strongly depending on the solubility in water and other solvents. Deacetylation degree (DDA) and molecular weight (MW) are the most decisive parameters on the bioactivities since the primary amino groups are the key functional groups of chitosan where permits to interact with other molecules. Higher DDA and lower MW of chitosan and chitosan derivatives demonstrated higher antimicrobial, antioxidant, and anticancer capacities. Therefore, the chitosan oligosaccharides (COS) with a low polymerization degree are receiving a great attention in medical and pharmaceutical applications as they have higher water solubility and lower viscosity than chitosan. In this review articles, the antimicrobial, antioxidant, anticancer, anti-inflammatory activities of chitosan and its derivatives are highlighted. The influences of physicochemical parameters of chitosan like DDA and MW on bioactivities are also described.

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Competitive Biological Activities of Chitosan and Its Derivatives: Antimicrobial, Antioxidant, Anticancer, and Anti-Inflammatory Activities

A real-time colorimetric and ratiometric fluorescent probe based on modulating the intramolecular charge transfer (ICT) of the coumarin platform for selective detection of sulfite is presented. This reaction based probe utilized the Michael addition to the dicyano-vinyl group with the detection limit of 5.8 × 10−5 M. The probe displayed a high selectivity for sulfite over other anions and reactive sulfur especially for biothiols including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), with about 100 nm blue shift and more than 230 times intensity ratios change of the emission spectrum. Meanwhile, it could be easily observed that the probe for sulfite changes from red to pale yellow by the naked eye, and from red to blue under UV lamp immediately after the sulfite is added. To the best of our knowledge, it is the fastest response probe for sulfite ever reported, which could give a colorimetric and ratiometric fluorescent response instantly.

A real-time colorimetric and ratiometric fluorescent probe for sulfite.

Synthesis, antimicrobial, antioxidant, anti-hemolytic and cytotoxic evaluation of new imidazole-based heterocycles.

Synthesis of new iminocoumarins and their transformations into N-chloro and hydrazono compounds

The purpose of this work was to develop new additive combinations between chitosan and curcumin in solutions as a fiber-coating. Diverse additive combinations between chitosan and curcumin in solutions were adsorbed onto viscose fabrics in order to reach the essential antimicrobial and antioxidant functionalization for medical textiles. The goal of this paper was to examine the adsorption of these two compounds as an additive formulation on viscose textile material as well as to analyze the desorptions of both substances from the fabric surface. Finally, the antimicrobial and antioxidant properties of viscose fabrics functionalized by chitosan–curcumin formulations were respectively examined. Curcumin as an adsorbate for textiles in combination with chitosan represents an added-value because of its anti-oxidative properties, and showing the potential to enhance existing antimicrobial performance of chitosan when applied using the preferred procedure.

Antimicrobial and antioxidant functionalization of viscose fabric using chitosan–curcumin formulations

Novel N-chlorinated derivatives of 2H-1-benzopyran-2-imines

Alkyl protected equivalents of hydroquinono-2-oxiranecarbonitriles 3 were prepared and applied in the synthesis of thiazolinone 5 and 7, thiazole 8 and oxathiole 9 derivatives directly linked to the precursor of the quinonic part of the molecule. The synthesis of 2-[(1,4naphthoquinolyl)amino]thiazole derivatives 11 is also reported.

2-Oxiranecarbonitriles in the synthesis of linked quinono heterocyclic derivatives

The Knoevenagel reaction between 2-hydroxybenzaldehydes and active methylene compounds (malononitrile and ethyl cyanoacetate) produces iminocoumarins and/or coumarins. In order to study the reactivity of the prepared iminocoumarins, chlorination and reaction with N-nucleophiles were studied.

Julija Volmajer

Papers

Synthesis of new iminocoumarins and their transformations into N-chloro and hydrazono compounds

Antimicrobial and antioxidant functionalization of viscose fabric using chitosan–curcumin formulations

Novel N-chlorinated derivatives of 2H-1-benzopyran-2-imines

2-Oxiranecarbonitriles in the synthesis of linked quinono heterocyclic derivatives

Synthesis of New Iminocoumarins and Their Transformations into N-Chloro and Hydrazono Compounds.