Reactivity of quinones towards chitosans

Current literature indicates that the reactivity of quinones towards chitosans is a topic of expanding interest, notwithstanding the analytical difficulties involved in the study of this class of reactions. The natural systems based on the tyrosinase-catalysed generation of quinones and their reactivity towards amines are taken as models in order to capture phenols, in food technology, to prepare biomaterials and to immobilise enzymes. Data obtained via combinatorial screening by coupling confirm that the selection of suitable compounds for reaction with chitosans can be made on the basis of the experimental evidence only, and no a priori theoretical consideration would be of help in predicting the behaviour of quinones towards chitosans: as an example, data concerning the efficient coupling of menadione and the scarce coupling of plumbagin are briefly presented.