Azo-Dyes-Grafted Oligosaccharides—From Synthesis to Applications

Abstract

Azobenzenes are photochromic molecules that possess a large range of applications. Their syntheses are usually simple and fast, and their purifications can be easy to perform. Oligosaccharide is also a wide family of biopolymer constituted of linear chain of saccharides. It can be extracted from biomass, as for cellulose, being the principal constituent of plant cell wall, or it can be enzymatically produced as for cyclodextrins, having properties not far from cellulose. Combining these two materials families can afford interesting applications such as controlled drug-release systems, photochromic liquid crystals, photoresponsive films or even fluorescent indicators. This review will compile the different syntheses of azo-dyes-grafted oligosaccharides, and will show their various applications.

Modifying electron injection kinetics for selective photoreduction of nitroarenes into cyclic and asymmetric azo compounds

“…We envisioned that fine tuning the entry behavior of electron donors into the hosts would balance the kinetics between electron injection and substrate reduction, generating unique selectivity different from the reported abiotic manifolds 16 , One of the important catalytically relevant but still sluggish conversions is selective reduction of nitroarenes into azo products 17 – 20 , due to the inherent complexity of the nitro reduction processes 21 – 24 and the distinctive application of azo compounds in the areas of liquid crystals, photochemical switches and sensitive shuttles (Fig. 1a ) 25 – 28 , We proposed that with the capsule was large enough to encapsulate more than one substrate molecules, the slower electron injection kinetics from the electron donors to the dye-loaded capsule would retard the electron transfer to recover the photosensitizer, dominating a stepwise reduction of nitroarenes. Such that in situ formed azanol and nitroso intermediates possibly condensed together to form the corresponding azo products within the capsule before they were further reduced or squeezed out of the capsule 29 – 31 .…”

Synthesis and Characterization of a Novel Dapsone-Derived Bisazo Ligand and Its Gold(III) Complex, with Evaluation of Its Antioxidant and Anticancer Activities

“…Bisazo compounds, distinguished by the presence of two azo groups in their structure, have demonstrated a wide range of applications in the pharmaceutical and medical sectors [7]. These applications encompass, but are not limited to, their utilization as drug candidates, biologically active molecules, and cellular staining agents, facilitating the visualization of cellular components and metabolic processes [8][9][10][11]. Comprehending the synthesis and coordination chemistry of bisazo ligands, such as the one derived from dapsone, can open new avenues for the development of biologically active compounds and therapeutic agents.…”

Intramolecular crankshaft-type rearrangement in a photoisomerised glycoconjugate

“…Conjugated compounds with various bulky substituents, showing the photochemical activity, have been recently investigated. [9][10][11] Incorporation of glycoconjugate moiety into photoactive structures result in the synthesis of a new class of photoactive glycoconjugates that can exhibit such interesting properties as controlled and reversible conformational switching. Glycoconjugates are important not only from the biophysical point of view 12 (for e.g.…”