Antihypotensive potency of p-synephrine: Spectral analysis, molecular properties and molecular docking investigation

In this study p-synephrine, a catecholamines that has sympathomimetic potency especially for hypoten-sion management was investigated for the effect of dielectric constant on non-linear optics (NLO), struc-tural benchmarking, population analysis by applying density functional theory (DFT), molecular docking, and spectroscopic and X-ray crystallography technique (FT-IR, Raman, UV-Vis, NMR and XRD). The XRD data at room temperature, indicates crystal structure of p-synephrine to be Lattice yype P, with mon-oclinic space group P2 1 /c (#14-1) with a = 8.85040 A, b = 12.11660 A, c = 9.78200 A, alpha = 90.0000 degrees, beta = 122.5510 degrees and gamma = 90.0 0 0 0 degrees to select the functional that best describe the theoretical properties p-synephrine, a selected functionals; APFD, BHandHLYP, M08HX, PBE0 and TPSSTPSS, all at 6-311 ++ g (2d,2p) same level of theory, geometric structural parameter (bond length, bond angle, and dihedral an-gle) of the optimized structure was compared to x-ray crystallography pattern. The energy gap (Egap), de-creases in the order of PBE0:4.086 approximate to TPSS:4.266 < APFD: 5.874 < M08HX: 6.710 < BHandHLYP: 7.204 eV. NBO analysis, indicates the highest stabilization energy of 332.24 kcal.mol -1 for BHandHYLP due to in-ternal charge transfer of electron from zr*C1-C3 donor bond orbital to zr*C1-C6 acceptor bond orbital. M08HX indicated the highest NLO parameter, dipole moment at 3.518, Static polarizability of-71.588 a.u and change in static polarizability of 14.318 a.u. and static first hyper polarizability a.u. Experimental and theoretical spectroscopic data indicated a very close agreement. The molecular docking showed that p-synephrine is an excellent candidate for further clinical studies as a antihypotensive candidate due to its higher binding affinity compared to standard drug dobutamine.(c) 2022 Elsevier B.V. All rights reserved.