Lolium perenne L., a common plant perennial ryegrass from Europe, northern Africa and Asia, was selected to produce biomass under field conditions. The biomass of this nonfood crop was from a highly contaminated agricultural soil by potentially toxic metals (Cd, Pb and Zn) with the aim of maintaining the agricultural vocation of these soils. In this perspective and in view of the metal concentration (Cd, Pb, Zn, macro- and micro-nutrients), the biomass of ryegrass was considered as a bio ’ore’ resource and was used as the starting material for the preparation of contemporary biosourced catalysts. The heterogeneous catalyst from the current work was successfully used in the synthesis of Moclobemide, used to treat anxiety and major depressive episodes. Through this original approach, Moclobemide was synthesized in one step, in 80% yield under solvent-free conditions.