GL-II-73 (GL-ii-073) is a benzodiazepine derivative related in chemical structure to compounds such as midazolam and adinazolam. It is described as an ñ<sub>5</sub> preferring positive allosteric modulator of the benzodiazepine site of GABA<sub>A</sub> receptors, with weaker activity at ñ<sub>2</sub> and ñ<sub>3</sub> and no significant affinity for the ñ<sub>1</sub> subtype. In animal tests it was found to produce effects consistent with antidepressant, anxiolytic and nootropic actions. It is now being researched as a potential treatment agent for Alzheimer's disease.