“…Carbolines are a remarkable family of heterocyclic natural products, with outstanding pharmacological potential. They are determined by their tricyclic, pyridine-fused indole framework (where the rings are identified as A, B and C), and classified according to the degree of saturation (fully saturated: 1,2,3,4-tetrahydro; partially saturated: 3,4-dihydro; and unsaturated β-carbolines) and the position of the N-atom in the C-ring as α-, β-, γ-or δ-carbolines ( Figure 1) [1,2]. β-Carboline alkaloids are widely distributed in nature including various plants, foodstuffs, marine creatures, insects, mammals as well as human tissues and body fluids.…”