Theanine. Molecular model of the drug theanine (C7.H14.N2.O3). This is an amino acid analogue of the proteinogenic amino acids L-glutamate and L-glutamine found primarily in particular plant and fungal species. It was discovered as a constituent of green tea. Theanine is reported to help with anxiety, blood pressure control, mood, and cognition. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (blue) and oxygen (red). Illustration.