Grafting Nature‐Inspired and Bio‐Based Phenolic Esters onto Cellulose Nanocrystals Gives Biomaterials with Photostable Anti‐UV Properties

Abstract

Invited for this month's cover is the international collaborative work from the Bioresource Processing Research Institute of Australia (BioPRIA)‐Monash University and URD Agro‐Biotechnologies Industrielles (ABI)‐AgroParisTech. The cover image shows how the grafting of Nature‐inspired and bio‐based phenolic esters on cellulose nanocrystals through click‐chemistry provides materials with highly photostable UV‐blocking properties. Cover art by David Mendoza. The Full Paper itself is available at 10.1002/cssc.202002017.

Immobilization of Adenosine Derivatives onto Cellulose Nanocrystals via Click Chemistry for Biocatalysis Applications

“…The azidation reaction is highly efficient, as the DS and DS surf achieved are 0.15 and 0.5, respectively. These correspond to the maximum theoretical substitution of hydroxyl groups on CNCs. , The grafted CNCs achieved DS and DS surf ranging from 0.09–0.12 and 0.14–0.28, respectively; these DS are similar to those reported for phenolic grafting . These correspond to 28% to 56% conversion of the azide groups by their triazole derivatives and agree with FTIR analysis.…”

“…The reactive hydroxyl groups on the cellulose surface can be easily modified with a wide range of functionalities. Click chemistry applications − have been reported, including a novel synthetic route for decorating cellulose nanocrystals with UV-absorbing phenolic esters, − and a thermoreversible nanofibrillar supramolecular hydrogel for the growth and release of cancer spheroids . Here, the synthesis of grafted alkyne adenosine derivatives on CNC-N 3 nanocellulose using copper-catalyzed cycloaddition click chemistry is investigated. , …”

“…Surface tosylation and azidation reactions of CNCs were performed following the same procedure as presented in a previous study . CNCs (5.0 g, 30.85 mmol anhydroglucose unit (AGU)) were suspended in 100 mL of pyridine and cooled to 10 °C.…”

“…The synthesis and characterization of the grafted adenosine derivatives followed our previous study where we grafted phenolic compounds with an alkyne moiety onto CNC azide (CNC-N 3 ) . The synthesis was performed by activation of the primary hydroxy groups of CNCs by tosylation, followed by nucleophilic substitution of the resulting tosylates with azide groups (Figure a, pathway 1).…”

“…Analysis and instruments (Fourier Transform Infrared (FTIR) spectrometerAgilent Technologies Cary 630 FTIRequipped with a diamond ATR accessory) were the same as those used in a previous study . Freeze-dried samples were analyzed with 32 scans at 4 cm –1 resolution and were recorded in the range of 4000–500 cm –1 .…”