PhD defense: Jinbiao Jiao

Title:

Photochromic glycomacrocycles: synthesis, characterization and light-controlled stereoselective glycosylation investigation

Abstract:

Recently, photochromic molecules have found increasing applications in chemistry, materials sciences, biology and photopharmacology through spatial and temporal photocontrol of conformation, physicochemical properties, chemical reactivity, biological and pharmacological activities in a reversible way. We are interested in the development of photoswitchable carbohydrates, in particular the synthesis of photoswitchable glycomacrocycles so as to modulate their physicochemical, chemical and biologic properties by light.
In this thesis, we have investigated the influence of light illumination on the stereoselectivity of intramolecular glycosylation by using dihydroxyazobenzene as photochromic template, and prepared two series of photoswitchable glycomacrocycles. The efficiency and the stereoselectivity of glycosylation have been found to be dependent on the nature of the linkers and glycosyl acceptor, as well as the configuration of the azobenzene tether. Excellent 1,2-cis mannosylation can be obtained with glycosyl acceptors bearing a primary hydroxyl group. Photophysical investigations revealed that the synthesized glycomacrocycles show excellent photophromic properties with high fatigue resistance. Chirality transfer from sugar to azobenzene moiety has also been observed. Preliminary results showed light-controlled metal ion complexing properties of glycomacrocycle with chiroptical property switching upon ion-complexation.

 

Composition of the jury:

Dr. Véronique BONNET (Université de Picardie Jules Vernes), Rapportrice
Pr. Nadège LUBIN-GERMAIN (CY Cergy-Paris Université), Rapportrice
Dr. Mickaël MENAND (Sorbonne Université), Examinateur
Dr. Samir MESSAOUDI (Université Paris-Saclay ), Examinateur
Pr. Joanne XIE (ENS Paris-Saclay), Directrice de thèse
Dr. Stéphane MAISONNEUVE (ENS Paris-Saclay), Co-encadrant de thèse