Discovery of an isocoumarin analogue that modulates neuronal functions via neurotrophin receptor TrkB

Isocoumarins are lactone ring-containing natural products, are quite abundant in microbes and higher plants, and have been shown to exhibit a broad range of pharmacological properties. However, the molecular mechanism or target of this class of molecules is not known. In this study, we have synthesized 14 isocoumarin derivatives and evaluated for their activity at TrkB receptor in transiently transfected HEK293T cells. We identified 8-hydroxy-3-aryl isocoumarin (1) as a high-affinity agonist at the TrkB receptor. We also demonstrated that isocoumarin 1 activated endogenously TrkB receptor in primary cortical neurons and modulated various markers of synaptic plasticity, and increased dendritic arborization. These results indicate therapeutic potential and molecular target of 8-hydroxy-3-aryl isocoumarin 1 for the treatment of various CNS disorders.