Xanthine oxidase inhibitory activity of new pyrrole carboxamide derivatives: In vitro and in silico studies.

Pyrrole carboxamide rings are rarely used as active scaffold in designing inhibitors for enzymes. Herein, we described the structure-activity relationship for novel xanthine oxidase inhibitors based on the pyrrole carboxamide scaffold. A series of novel-substituted pyrrole carboxamide derivatives were synthesized and characterized; their in vitro and in silico inhibitory activities were determined against xanthine oxidase. Among these compounds, those which contain no substituent and one methyl group at the para-position of the phenyl moiety in the main structure, respectively, were found out as most active according to the xanthine oxidase inhibition activity study. In silico techniques reveal why these compounds display more activities than others, based on their binding interactions with xanthine oxidase and the surface scanning results of the enzyme. Furthermore, the binding energy calculations displayed good agreement with the experimental activity values.

Synthesis, characterization and vibrational spectra analysis of ethyl (2Z)-2-(2-amino-4-oxo-1,3-oxazol-5(4H)-ylidene)-3-oxo-3-phenylpropanoate.

In the present study, the experimental and theoretical vibrational spectra of ethyl (2Z)-2-(2-amino-4-oxo-1,3-oxazol-5(4H)-ylidene)-3-oxo-3-phenylpropanoate (AOX) were investigated. The experimental FT-IR (400-4000 cm(-1)) and Laser-Raman spectra (100-4000 cm(-1)) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles and torsion angles) were calculated using ab initio Hartree Fock (HF), Density Functional Theory (B3LYP and B3PW91) methods with 6-311++G(d,p) basis set by Gaussian 03 program, for the first time. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. The hydrogen bonding geometry of the molecule was also simulated to evaluate the effect of intermolecular hydrogen bonding on the vibrational frequencies. Also, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies were found.