Tanveer Hasan

VIBRATIONAL DYNAMICS AND POTENTIAL ENERGY DISTRIBUTION OF TWO WELL-KNOWN NEUROTRANSMITTER RECEPTORS: TYRAMINE AND DOPAMINE HYDROCHLORIDE

This work deals with the theoretical study on the molecular structure of two well-known neurotransmitter receptors tyramine hydrochloride and dopamine hydrochloride. The equilibrium geometry, harmonic vibrational frequencies, infrared intensities, and Raman scattering activities were calculated by the density functional B3LYP method employing 6-311G(d,p) as the basis set and the vibrational studies were interpreted in terms of the potential energy distribution (P.E.D.). The internal coordinates were optimized repeatedly to maximize the P.E.D. contributions. A detailed interpretation of the infrared and Raman spectra of tyramine and dopamine hydrochloride is reported in the present work. The similarities and differences between the vibrational spectra of the two molecules studied have been highlighted. The scaled theoretical wave numbers are in perfect agreement with the experimental values. The thermodynamic calculations related to the title compounds were also performed at B3LYP/6-311G(d,p) level of theory. The FT-Raman and FT-IR spectra of tyramine and dopamine hydrochloride have been taken from literature.

FT-IR spectra and vibrational spectroscopy of Andrographolide

A complete normal coordinate analysis was performed for andrographolide in terms of the calculation by using Wilsons G-F matrix method and Urey Bradley force field. Normal coordinate analysis has been carried out to understand the dynamical behaviour of the bioactive labdane diterpenoid of the medicinally useful terrestrial plant Andrographis paniculata. The structural elucidation of a novel, biologically active natural product followed by its total synthesis lays the groundwork for investigations into its biological mechanism of action including putative cellular receptor isolation.

Vibrational Dynamics of the Diterpene-Neoandrographolide

A complete normal coordinate analysis was performed for neoandrographolide in terms of the calculation by using Wilson’s G-F matrix method and Urey Bradley force field. Andrographis paniculata has been reported for its potent hepatoprotective. Andrographis paniculata has been reported to have antisecretory (antidiarrhoeal), immunostimulant, antimalarial, antifilarial activity. It is also reported to have anticancer, anti HIV, anti-inflammatory, hypotensive action. In addition, it has found to be effective in myocardial infraction.

Vibrational analysis of deoxy-andrographolide using MM/QM methods

Bioactive natural products have an enormous economic importance as speciality chemicals. Extracts of the shrub Andrographis paniculata are widely used as herbal medicines in many countries. Diterpenoid lactones isolated from these extracts have been the subject of extensive investigation, and one of its constituent diterpenoid is deoxy-andrographolide. A complete normal coordinate analysis was performed for deo-andrographolide in terms of the calculation by using Classical mechanics and Quantum mechanical methods.The study of vibrational spectra helps in understanding the dynamical behaviour and hence a lot of information can be derived about the conformation. The geometrical parameters and the vibrational spectra have been discussed in detail.

Vibrational and Quantum Chemical Study of Triphenylantimony(V)-o-salicylate

A complete normal coordinate analysis was performed by two different methods: a classical Wilson G-F matrix method and the semi-empirical molecular orbital PM3 method, for a five coordinate non rigid triphenyl antimony diester SbPh3(O2CR)2,[R=C6H4OH-o], known to be a bioactive molecule. The study of vibrational spectra suggested that the title compound might have secondary bonding interaction between the central antimony atom and the carbonyl oxygen atoms. The atomic charge distribution, geometry optimization and thermochemistry, were also calculated by PM3 method, which help in finding the potential sites of the title compound.