Structure-Activity Relationship and Bioactivity Studies of Neurotrophic trans-Banglene

Neurotrophic small molecule natural products are functional analogs of signaling proteins called neurotrophins, which cause a pro-growth, pro-survival, or pro-differentiation response in neuronal cells. While these phenotypic responses are desirable to combat neurodegenerative disease progression, the pharmacokinetic properties of neurotrophins present challenges to their administration. Therefore, neurotrophic small molecules such as the cis- and trans-banglenes offer attractive alternatives. We describe the synthesis and testing of banglene derivatives and establish a structure-activity response for the banglene family. We demonstrate that (–) trans-banglene is the primarily active enantiomer, and that select modifications on the cyclohexene ring of trans-banglene do not significantly impair its bioactivity. Finally, we demonstrate that (–) trans-banglene potentiation of NGF induced neuritogenesis is unaffected by the presence of these Erk1/2, Akt and Pkc inhibitors. Our structure-activity results also suggest that (–) trans-banglene neurotrophic activity and its potentiation of NGF activity might be distinct unassociated processes.