The present study was focused on understanding the binding interaction mechanism of a newly synthesized 1-imino-1,2-dihydropyrazino[1,2-a]indol-3(4H)-one(PI) compound in bovine serum albumin(BSA) using fluorescence spectroscopy and molecular modeling techniques. The target molecules of 5-hydroxytryptamine receptor 1B (5-HT1B) and human carbonic anhydrase I (HCA-I)for PI were also studied. The emission result confirms the static quenching nature for PI in BSA complex. In addition, the thermodynamical parameter calculation shows that the binding formation for PI in BSA environment is due to hydrophobic force. Further, the docking and dynamics studies also confirm the major influence of hydrophobic force of PI in BSA,5-HT1B and HCA-I microenvironment on the binding nature. In addition to this, density functional theory (DFT) calculation was carried out for free PI and PI in active site region (Single point DFT)to know the intermolecular interactions. © 2020 Elsevier B.V.