Harmane, a β-Carboline alkaloid (BCA), is a potent neurotoxin that causes severe action tremors and psychiatric manifestations. Harmane shows 1000-fold selectivity for?I1-Imidazoline receptor?(IC50=30 nM) over?α2-adrenoceptor?(IC50=18 μM). Harmane is also a potent and selective inhibitor of?monoamine oxidase (MAO)?(IC50s=0.5 and 5 μM for?human MAO A/B, respectively). Harmane exhibits comutagenic effect