The concept that the amino‐terminal segment plays a role in conferring high basal activity to protein kinase CK2 α subunit has been validated by generating two mutants (Y26F and Δ2–6) which are defective both in catalytic activity and in thermal stability. The additional finding that the activity of the two mutants is fully restored upon association with the regulatory β subunit, in conjunction with the observation that synthetic peptides reproducing the N‐terminal segment (1–30) and the activation loop (175–201) of CK2α counteract the functional effects of the C‐terminal domain of the β subunit, is consistent with a mechanism of activation of CK2 where the N‐terminal domain of α and the C‐terminal domain of β play interchangeable roles.

Neurodegenerative disorders, such as Parkinson's disease and Alzheimer's disease, constitute pathological conditions of great relevance on health span and quality of life. The identification of novel therapeutic options, able to modulate the processes involved in the insurgence and progression of neurodegenerative disorders, represents an intriguing challenge of current research. Herein, a library of 36-membered 2-(phenylamino)-7,8-dihydroquinazolinone derivatives was synthesized and biologically evaluated as human MAO inhibitors. Some compounds able to inhibit MAO-B potently and selectively (K_i in the nanomolar range) were identified, and robust structure-activity relationships were drawn, supported by computational studies. Further biological assays revealed a safe profile for all derivatives and, for compounds selected as the best MAO-B inhibitors (4, 5, 13, 14) the following properties also emerged: (i) the ability to inhibit MAO-B activity in whole cells, with an effectiveness comparable or slight lower with respect to the reference safinamide; (ii) physicochemical parameters suggesting drug-likeness properties; (iii) the ability to inhibit, albeit weakly, GSK3β kinase (for compound 4). Within the whole series, compound 4 stood out as a promising lead for future optimization campaigns aimed to obtain useful drugs for the treatment of Alzheimer's and Parkinson's diseases.