Photochromic meta-diamides for optical modulation of ligand activity and neuron function.

Photopharmacology offers facile solutions to spatiotemporal control over ligand activity and receptor function. Meta-diamide insecticide acts on insect GABA receptors (GABARs) as an antagonist that causes firing of a neuron. We present here photochromic GABAR ligands azobenzene-meta-diamides (ABMDAs) by incorporating photoswitchable azobenzene with meta-diamides. ABMDAs showed good isomerization efficiency and fatigue resistance. Among them, ABMDA7 shows a 1.5-fold insecticidal activity difference towards mosquito larvae (Aedes albopictus) before and after UV illumination. We translated this light-dependent activity difference to optical modulation of membrane potential of American cockroach (Periplaneta americana) DUM neurons. This light-responsive meta-diamide-based GABAR ligand allows for optical regulation of insecticidal activity and DUM neurons.