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Jun 2019 DOI 10.14302/issn.2377-2549.jndc-19-2765
Tetrodotoxin (TTX) is a potent neurotoxin. Its name derives from Tetraodontiformes, an order that includes pufferfish, porcupinefish, ocean sunfish, and triggerfish; several of these species carry the toxin. Although tetrodotoxin was discovered in these fish and found in several other aquatic animals (e.g., in blue–ringed octopuses, rough–skinned newts, and moon snails), it is actually produced by certain infecting or symbiotic bacteria like Pseudoalteromonas, Pseudomonas, and Vibrio as well as other species found in animals. Parameters such as FT–IR and Raman vibrational wavelengths and intensities for single crystal Tetrodotoxin (TTX)are calculated using density functional theory and were compared with empirical results. The investigation about vibrational spectrum of cycle dimers in crystal with carboxyl groups from each molecule of acid was shown that it leads to create Hydrogen bounds for adjacent molecules. The current study aimed to investigate the possibility of simulating the empirical values. Analysis of vibrational spectrum of Tetrodotoxin (TTX) is performed based on theoretical simulation and FT–IR empirical spectrum and Raman empirical spectrum using density functional theory in levels of F/6–31G*, HF/6–31++G**, MP2/6–31G, MP2/6–31++G**, BLYP/6–31G, BLYP/6–31++G**, B3LYP/6–31G and B3LYP6–31–HEG**. Vibration modes of methylene, carboxyl acid and phenyl cycle are separately investigated. The obtained values confirm high accuracy and validity of results obtained from calculations. Molecular structure of Tetrodotoxin (TTX) 1–42.
Apr 2017 DOI 10.14302/issn.2377-2549.jndc-17-1488
The compound 2-(4-methoxyphenyl)-2, 3-dihydro-1H-perimidine (MPDP) was synthesized. The molecular structure and its functional groups were characterized with the help of Fourier Transform Infrared: FTIR/ Fourier Transform FT-Raman spectra in the regions of 400-4000/50-4000cm-1, respectively. The geometrical parameters, harmonic vibrational wavenumbers, Infrared (IR) & Raman scattering intensities, Nuclear Magnetic Resonance (NMR) chemical shift and Ultraviolet-Visible (UV-Vis) spectra were computed using B3LYP/6-311++G(d,p) level of theory. The complete vibrational analysis were made on the basis of Potential energy distribution (PED) calculation with the help of VEDA4 programme. The Highest occupied molecular orbital (HOMO) – Lowest unoccupied molecular orbital (LUMO) energy gap and intra-molecular charge transfer (ICT) were studied using NBO analysis. The first order hyperpolarizability (β0) and other related properties (β, α0, Δα) of MPDP were computed. The molecular electrostatic potential (MEP), Mulliken atomic charges were calculated using the same level of theory. In addition, the various thermodynamic parameters were also calculated.
Aug 2017 DOI 10.14302/issn.2377-2549.jndc-17-1645
The structure of the newly synthesized hydrazone derivative 2 - 6 – oxo - 2-thioxotetrahydropyrimidin – 4 1H - ylidene hydrazine carbothioamide (OTTHPYHCT)compound is determined by using spectral information and elemental study. Density functional theory (DFT) studies were performed using the B3LYP/6-31G (d, p) basis set to expand imminent into their structural properties. Frontier molecular orbital (FMO’s) analysis of title compoundwas computed at the same level of theory to get knowledge about their kinetic stability of the molecule by the energy gap value obtained. Global reactivity descriptors are determined to explain the biological activity of the molecule. NBO analysis provides information about charge transfer, delocalization effect, hyperconjugative interactions and the energy responsible for the stabilization of the compound. First hyperpolarizability analysis nonlinear optical response was simulated at the B3LYP/6-31G d, p level of theory as well. Thermodynamic parameters explain vibrational intensity of the molecule.