Notable scientific achievements were among other things his isolation and characterization of properties of asparagine (the first amino acid to be identified, from asparagus, achieved. In 1806, with Louis Nicolas Vauquelin), cantharidin (1810), the Sigma-1 receptor agonist noscapine (1817), caffeine (1821), alizarin (later on moved to mass industrial production by Carl Gräbe and Carl Theodore Liebermann in Germany, and by William Henry Perkin in Great Britain) and purpurin (1826), Orcin (1829), amygdalin (1830), as well as codeine (1832). Some of these discoveries were made in collaboration with other scientists.