The present invention relates to chiral esters of polysaccharides, preferably of cellulose, amylose, -cyclodextrin or amylopectin, obtained by reacting, in basic medium, polysaccharides (polyhydroxylated compounds) with racemic or enriched acid chlorides bearing a hydrogen and an aromatic group on their a carbon. This acid precursor (I) may be -phenylpropionic acid, ibuprofen, ketoprofen or naproxen and, more generally, any acid derivative which may lead to a reactive form of ketene type. These novel asymmetric esters of polyhydroxylated compounds may be used as means of chiral enrichment, as medicinal systems with sustained and controlled release of enriched chiral active principles, these active principles consisting of the acyl parts of the esters grafted onto the hydroxyls (or even onto the amines) of the polyhydroxylated compounds, or alternatively as chiral stationary phases (CSPs). The invention is also directed toward a process for preparing these esters, to a chiral enrichment process and to the enrichment means, the medicinal systems and the CSPs targeted above.