<p>Сhitosan derivatives, in particular, ascorbate chitosan and nanoascorbate chitosan, which are not toxic to the environment and have bactericidal, growth-promoting and antifungal properties, is the subject of great interest in the world. Modern scientific literature has been studied, highlighting the preparation and physicochemical properties of these derivatives of chitosan. The optimal synthesis conditions were determined by ionotropic gelation of nanoascorbate chitosan as a cost-effective one. For the first time, the principal possibilities of obtaining ascorbate and nanoascorbate chitosan based on chitosan Bombyx mori are shown. Based on the published and own experimental data, the pronounced biological activity of ascorbate chitosan and nanoascorbate chitosan Bombyx mori is shown to suppress human and plant pathogens during the presowing treatment of agricultural seeds with innovative encapsulation technology. </p>