Theanine, commonly known as L-theanine and sometimes L-gamma-glutamylethylamide or N⁵-ethyl-L-glutamine, is an amino acid analogue of the proteinogenic amino acids L-glutamate and L-glutamine and is found primarily in particular plant and fungal species. It was discovered as a constituent of green tea in 1949 and isolated from gyokuro leaves in 1950, thus rendering it a natural product. It constitutes about 1–2% of the dry weight of green tea leaves. Theanine provides a unique brothy or savory (umami) flavor to green tea infusions.