1-Amino-5-phosphonoindan-1-carboxylic acid (APICA) is a drug that is used in neuroscience research. It is a selective antagonist for the group II metabotropic glutamate receptors ( mGluR), and has been useful in the study of this receptor subfamily.
APICA (synthetic cannabinoid drug)
It had never previously been reported in the scientific or patent literature, and was first identified by laboratories in Japan in March 2012 as an ingredient in synthetic cannabis smoking blends, along with its indazole derivative APINACA (sold as "AKB48").
Structurally it closely resembles cannabinoid compounds from patent WO 2003/035005 but with an indole core instead of indazole, and a simple pentyl chain on the indole 1-position.
Pharmacological testing determined APICA to have an IC of 175 nM at CB, only slightly less potent than JWH-018 which had an IC of 169 nM, but over four times more tightly binding than APINACA, which had an IC of 824 nM. The first published synthesis and pharmacological evaluation of APICA revealed that it acts as a full agonist at CB ( EC = 34 nM) and CB receptors (EC = 29 nM). Furthermore, APICA possesses cannabis-like effects in rats, and appears to be less potent than JWH-018 but more potent than THC.