Development of Optical Biosensor for the Detection of Glutamine in Human Biofluids Using Merocyanine Dye

Merocyanine dye based fluorescent organic compound has been synthesized for the detection of glutamine. The probe showed remarkable fluorescent intensity with glutamine through ICT (Intermolecular Charge Transfer Mechanism). Hence, it is tested for the detection of glutamine using colorimetric and fluorimetric techniques in physiological and neutral pH (7.2). Under optimized experimental conditions, the probe detects glutamine selectively among other interfering biomolecules. The probe has showed a LOD (lower limit of detection) of 9.6?×?10^–8 mol/L at the linear range 0–180 µM towards glutamine. The practical application of the probe is successfully tested in human biofluids.

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Effective Detection of Phenylalanine Using Pyridine Based Sensor

Journal of Fluorescence - Pyridine based organic molecule as probe has been synthesized for the detection of phenylalanine (PA) biomarker. The synthesized probe is characterized by 1H and 13C NMR...     

Model calculations for the base-pairing specificity of mutagenic exocyclic DNA adduct 1,N 6-ethenoadenine

1,N ⁶-ethenoadenine (εA) has been studied more extensively due to highly fluorescent and mutagenic nature. We report the model calculations for the base-pairing specificity of mutagenic 1,N ⁶-ethenoadenine adduct. To shed insight into mutagenic process of DNA damage based on geometrical characteristics, electronic properties, B3LYP, M06, B97D, and wB97XD methods have been employed for these model calculations. Single point energy calculation at MP2/6-311++G** levels on corresponding B3LYP, M06, B97D, wB97XD-optimized geometries have also been carried out to better estimate the hydrogen-bonding strengths. The polarisable conductor calculation model (CPCM-UAKS) that accounts for the overall polarizability of the solvent has also been employed. The computed reaction enthalpy values concluded that both guanine and thymine are most favorable candidates to be misincorporated to 1,N ⁶-ethenoadenine adduct, which also in good agreement to experimental report (Leonard, Biochemistry 33: 4755–4761, 79).     

The role of cesium fluoride in aryl propargyl ether Claisen rearrangement and its mechanistic elucidation: a theoretical study

The role of cesium fluoride (CsF) in aryl propargyl ether Claisen rearrangement and its mechanistic pathway have been investigated in gas and solvent phase using the density functional theory implemented in Gaussian 09. Our results indicate that the [3,3]-sigmatropic rearrangement is the rate-limiting step with ΔG ^? value of 37.1 kcal/mol in solvent phase. Furthermore, the results show that the enolization of α-allenylketone intermediate (Int1-CsF) has a higher free energy barrier, which implies that the formation of benzopyran is not favored in the presence of CsF. However, the abstraction of the α-hydrogen atom in Int1-CsF with CsF shows a very low free energy barrier and is the most favored pathway for aryl propargyl ether Claisen rearrangement in the presence of CsF to form benzofuran. In the case of substituted aryl propargyl ethers, a methoxy group on the benzene ring lowers the activation barrier. The HOMO–LUMO, conformational and NBO analysis indicate that increasing methyl substitution on the propargyl residue enhances the rearrangement reaction.