Sweet switches: azobenzene glycoconjugates synthesized by click chemistry

Abstract

Azobenzene glycoconjugates can be switched between two isomeric states, E and Z, to change the spatial orientation of the conjugated carbohydrate ligands. Mono-, di- and trivalent azobenzene glycoconjugates were synthesized using click chemistry and their photochromic properties determined. Multivalency effects were observed in photoisomerisation.

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

“…Thus, our novel “sweet switches” [15] appear to be highly promising FimH ligands, with the additional feature of a photoswitchable moiety. The biomedicinal potential of azobenzene glycosides seems even higher when their favourable physiological properties are considered, such as low toxicity [36] and receptor specificity of the azobenzene aglycon [37].…”

“…In the case that the E → Z isomerisation process is high-yielding and the lifetime of the ( Z )-form of the azobenzene glycoside is long enough, it can be employed in bacterial adhesion assays independently from the more stable ( E )-isomer. Eventually, this type of azobenzene mannobioside can be further functionalised to be attached to various supports such as oligofunctional core molecules [15] or surfaces, to achieve switchable adhesive surfaces in continuation of our work on glycoarrays [16–18] (Fig. 1).…”

Light‐Triggered Azobenzenes: From Molecular Architecture to Functional Materials

“…Azobenzene is doubtless the most widely used organic chromophore for photoswitching purposes in biological systems, since it can be successfully incorporated into all types of biopolymers (including peptides, proteins, sugars, and DNA) [50][51][52][53][54]. Indeed, a wide variety of azoderivatives have been used in diverse biological and medical applications, for example, as photoswitchable ion channel blockers, to photocontrol of not only the activity of enzymes but also the concentration of neurotransmitters in the central nervous system, and optogenetics.…”

Synthesis of Hetero‐bifunctional Azobenzene Glycoconjugates for Bioorthogonal Cross‐Linking of Proteins

“…[9,10] For example, p,p′-dihydroxyazobenzene has been used for the synthesis of symmetrical azobenzene glycosides; [3,10,11] however, it does not offer entry into hetero-bifunctional azobenzene derivatives. [9,10] For example, p,p′-dihydroxyazobenzene has been used for the synthesis of symmetrical azobenzene glycosides; [3,10,11] however, it does not offer entry into hetero-bifunctional azobenzene derivatives.…”