Modelling of serotonin reuptake inhibitory and histamine H₃antagonistic activity of piperazine and diazepane amides: QSAR rationales for co-optimization of the activity profiles.

Selective human serotonin reuptake transporter (hSERT) inhibition is the first line of treatment to deal with the depression. In clinical practice for managing depression, the stimulants are co-prescribed to overcome cognitive impairment and fatigue. Recently, histamine H(3) antagonists with serotonin reuptake inhibition activity have been proposed as alternative approach for the treatment of depression. In this context, a QSAR study of hSERT inhibitory and H(3) antagonistic activity of piperazine and diazepane amide derivatives has been carried out using the combinatorial protocol in multiple linear regression (CP-MLR) with 0D- to 2D-Dragon descriptors. The derived QSAR models have provided a rational approach for the development of new piperazine and diazepane amide derivatives as hSERT inhibitors and H(3) antagonists. In a concomitant partial least-squares (PLS) analysis of the hSERT and histamine H(3) activities, the fraction contributions of identified descriptors revealed their importance in modulating these activities. The PLS analysis of other biological endpoints, namely hNET, hDAT, and histamine H(3) activity in functional assay (H(3)pA(2)) of these analogues with the identified descriptors has further highlighted their scope in modulating these activities.