L-AP4

**L-AP4** is a small molecule, synthetic, non-proteinogenic amino acid that acts as a potent and selective **agonist for the group III metabotropic glutamate receptors** (mGluR4, mGluR6, mGluR7, and mGluR8)[1][3][9][11]. It works by binding presynaptically to these receptors—primarily in the central nervous system—where it functions to suppress glutamate release and depress synaptic transmission in glutamatergic pathways, including the hippocampus, olfactory bulb, and retina[9][4]. It is widely used as a research tool to probe the function of group III mGluRs, but it is not approved for therapeutic or diagnostic use in humans[11].

Other names

(2S)-2-amino-4-phosphonobutanoic acidL-(+)-2-amino-4-phosphonobutyric acid(S)-2-amino-4-phosphonobutyric acidL-AP-4L-AP4L-AP 42-amino-4-phosphono-butyric acid