Discovery of a potent, orally bioavailable and highly selective human neuronal nitric oxide synthase (nNOS) inhibitor, N-(1-(piperidin-4-yl)indolin-5-yl)thiophene-2-carboximidamide as a pre-clinical development candidate for the treatment of migraine

We recently reported a series of 1,6-disubstituted indoline-based thiophene amidine compounds (5) as selective neuronal nitric oxide synthase (nNOS) inhibitors to mitigate the cardiovascular liabilities associated with hERG K+ channel inhibition (IC50 = 4.7 μM) with previously reported tetrahydroquinoline-based selective nNOS inhibitors (4). The extended structure–activity relationship studies within the indoline core led to the identification of 43 as a selection candidate for further evaluations. The in vivo activity in two different pain (spinal nerve ligation and migraine pain) models, the excellent physicochemical and pharmacokinetic properties, oral bioavailability (Fpo = 91%), and the in vitro safety profile disclosed in this report make 43 an ideal candidate for further evaluation in clinical applications related to migraine pain.

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► A novel class of sixteen 1,5-disubstituted indoline derivatives were synthesized.
► These compounds were shown to be potent and selective inhibitors of human nNOS.
► These compounds mitigate cardiovascular liabilities (eNOS and hERG K+ activity).
► Therapeutic application was shown in two different pain (SNL and Migraine) models.
► Therapeutic application was further supported by safe side activity profile of 43.