Synthesis, Crystal Growth, and Computational Investigation of New Tetrahydroisoquinoline Derivatives Potent against Molecule Nitric Oxide Synthases

In the present work, we describe the synthesis of new tetrahydroisoquinoline derivatives and the crystal structures of two of them. Density functional theory (DFT) investigations at the B3LYP/6-31+G(d,p) level provided their structural reactivity and nonlinear optical properties. The low HOMO-LUMO gaps (EH-L) suggest a soft nature and higher reactivity, while calculated global reactivity descriptors provide assessments of their reactivity and electronic stability. The calculated natural bonding molecular orbital (NBO) charges show excellent charge separation (charge transfer) and identify the donor and acceptor parts of the molecules. Density of states (DOS) analyses show the newly generated energy states and reduced band gaps, which impart higher conductive properties. For surface reactivity, 3D MESP surfaces are plotted and show electron-rich sites near the nitrogen atoms of the tetrahydroisoquinoline rings. Nonlinear optical (NLO) properties of the crystals are predicted from calculated polarizability (αo) and hyperpolarizability (βo) values. For IVb, the αo and βo values are 415.53 and 1003.44 au. The remarkable value (1003.44 au) of the hyperpolarizability (βo) shows IVb has excellent NLO properties. Structural activity relationship analysis suggests that nitric oxide synthases are better targets for both compounds, and they were further subjected to molecular docking simulations to understand the binding efficiency. In addition, ADMET analyses were carried out to understand the potential activity of the molecules as drug candidates

Synthesis, crystal structure investigation, Hirshfeld and DFT studies of newly synthesized dihydroisoquinoline derivatives

Isoquinoline and its derivatives, which constitute an important category of heterocyclic compounds and are found in a variety of naturally occurring alkaloids, serve a variety of biological purposes such as a potent agonist for human melatonin receptors 1. This research was conducted in an attempt to develop new dihydroisoquinoline molecules (III and IV). Single-crystal X-ray crystallography study validated their structures. The Hirshfeld surface analysis identifies intermolecular interactions by using a 2-D fingerprint map to recognize each type's relative contribution H⋅⋅⋅H connections are discovered to be dominating. The interaction energies between chemical pairs in crystal structures were found using an energy framework analysis. The DFT investigation demonstrates the electronic stability and reactivity of the compounds using the HOMO-LUMO and global reactivity descriptors, indicating that IV has higher chemical reactivity than III. The derived polarizability (αo) and hyperpolarizability (βo) values were used to calculate the optical and nonlinear optical characteristics of III and IV. The IV's significant βo value (488.94 au) indicates that it has good optical and NLO qualities. Molecular docking simulation using human melatonin receptors 1 was used to better understand the binding interaction mechanism of the title compounds. In addition, ADMET evaluations were performed to establish the therapeutic potential of III and IV