Vibrational spectra, NBO, HOMO-LUMO and conformational stability studies of 4-hydroxythiobenzamide

Molecular conformation, vibrational spectroscopic and NBO analysis of atenolol and atenolol-hydrochlorothiazide cocrystals

Geometry optimization of atenolol (ATN) in the gas phase was carried out using B3LYP-D3BJ/6-31++G(d,p), CAM-B3LYP/6-31++G(d,p) and M06-2X/6-31++G(d,p) levels of DFT. The computed structural parameters were compared with the data obtained by single crystal X-ray diffraction experiment. Chemical reactivity (electronegativity, electrophilicity, hardness, chemical softness and chemical potential) was predicted with the help of HOMO- LUMO energy values. Experimental FT-IR was recorded and the calculated values were also analyzed using the same level of DFT. A complete vibrational spectrum was made to analyze the potential energy distribution (PED). Stability of the molecule arising from hyperconjugative interaction was analyzed by the natural bond orbital (NBO) analysis. The molecular electrostatic potential map was used to detect the possible electrophilic and nucleophilic sites in ATN molecule. Cocrystallization of atenolol-hydrochlorothiazide (ATN-HCTZ) was performed and the structure was analyzed by powder X-ray diffraction. NBO analysis was carried out on the ATN-HCTZ cocrystal for the elucidation of inter and intra-molecular hydrogen bonding interactions in the structure. Atenolol interaction with human serum albumin (HSA) was investigated by a molecular docking study.

Medicinal Plant Using Ground State Stabilization of Natural Antioxidant Curcumin by Keto-Enol Tautomerisation

Curcumin is a medicinal agent that exhibits anti-cancer properties and bioactive pigment in Turmeric has a huge therapeutic value. It has a keto-enol moiety that gives rise to many of its chemical properties. A recent study has shown that keto-enol tautomerisation at this moiety is implicated the effect of curcumin. The tautomerisation of curcumin in methanol, acetone and acetonitrile are used in nuclear magnetic resonance (1H, 13C) spectroscopy. It was characterized using UV, IR and Raman spectral values. The molecular electrostatic potential surface of the Curcumin has been visualized in electropositive potential in the region of the CH3+ group and most electronegative potential in the two oxygen atom has very strong binding group. In the following, the modality of structural and thermo dynamical parameters, electrophilicity (ω), chemical potential (μ), chemical hardness (η) and electronic charge transfer confirms the local reactivity. The rate constant of tautomerisation of curcumin shows strong temperature dependence. Molecular electrostatic potential and Temperature dependence of various thermodynamic properties like [Formula: see text] is increase with increase in temperature for monomer and dimer of various electrical fields.