Engineered mycosporine-based glucoconjugates by enzymatic cascade: Towards innovative ultraviolet filters and...

Mycosporine-serinol (MSer(OH)) is a small natural molecule with unique ultraviolet (UV) absorbing and antioxidant properties, but its hydrophilic and instable structure hampers its formulation for applications. Inspired by the fact that certain mycosporines are naturally glycosylated, this work assessed the development of an enzymatic route for the glucosylation of MSer(OH) using sucrose, a cheap and abundant resource. The newly characterized α-transglucosylase GS-D Δ1, from Ligilactobacillus animalis DSM 20602, stood out for its ability to glucosylate 96 % of MSer(OH) by grafting 1 to 3 glucosyl units. Then, an enzymatic cascade was established to produce various glucosylated-MSer(OH) differing in terms of linkage specificity and chain length. Their photostability and antioxidant capacities match those of free MSer(OH) or well-known antioxidants, making them potential competitors to commercial sunscreens. Notably, a MSer(OH)-based dextran chain over 10⁸ g.mol^-1 exhibited promising properties for cosmetic or medical formulations, as well as anti-UV bio-based materials.