Synthesis and Characterization of Some Novel 3-Bromo-2-acetylthiophene Chalcones and Biological Evaluation of Their Ethyl-4-(3-bromothien-2-yl)-2-oxo-6-(aryl)cyclohex-3-ene-1-carboxylate Derivatives

Attenuation of vincristine-induced neuropathy by synthetic cyclohexenone-functionalized derivative in mice model

Vincristine (VCR) is a well-known anticancer drug which frequently induced painful neuropathy and impairs the quality of life of patients. The present study was designed to investigate the alleviative potential of a novel cyclohexenone derivative (CHD), i.e., ethyl 6-(4-methoxyphenyl)-2-oxo-4-phenylcyclohexe-3-enecarboxylate, against VCR-induced neuropathic pain in mice model. VCR was administered intraperitoneally for 10 days in two cycles to induce neuropathic pain. Static and dynamic mechanical allodynia was evaluated using von Frey hair filaments and cotton buds, respectively. Paw thermal hyperalgesia was determined through a hot plate analgesiometer. The tail cold immersion hyperalgesia and paw cold allodynia were determined by available standard protocols. The formalin nociception was induced via subplantar injection of formalin. The antioxidant potential was evaluated via 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity. The outcome of this study revealed that CHD (30-45 mg/kg) and gabapentin (75 mg/kg) significantly enhanced the paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) in static and dynamic allodynia, respectively, and increased the PWL in thermal hyperalgesia and tail withdrawal latency (TWL) as compared to the VCR-treated group. CHD significantly augmented the paw withdrawal duration (PWD) in paw cold allodynia, while the same compound only increased the paw elevation and paw licking in the delayed phase of formalin nociception. Moreover, CHD significantly inhibited the DPPH free radical scavenging action (IC₅₀ = 56), butylated hydroxytoluene (BHT) (IC₅₀ = 39), and ascorbic acid (IC₅₀ = 2.93). In conclusion, CHD exhibited a profile of potential attenuative effect against the VCR-induced neuropathic pain which might be attributed to its possible antinociceptive and antioxidant effect.

Crystal structures of (2E)-1-(3-bromo-thio-phen-2-yl)-3-(2-meth-oxy-phen-yl)prop-2-en-1-one and (2E)-1-(3-bromo-thio-phen-2-yl)-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one

In the mol-ecules of the title compounds, (2E)-1-(3-bromo-thio-phen-2-yl)-3-(2-meth-oxy-phen-yl)prop-2-en-1-one, C14H11BrO2S, (I), which crystallizes in the space group P-1 with four independent mol-ecules in the asymmetric unit (Z' = 8), and (2E)-1-(3-bromo-thio-phen-2-yl)-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one, C15H13BrO3S, (II), which crystallizes with Z' = 8 in the space group I2/a, the non-H atoms are nearly coplanar. The mol-ecules of (I) pack with inversion symmetry stacked diagonally along the a-axis direction. Weak C-H⋯Br intra-molecular inter-actions in each of the four mol-ecules in the asymmetric unit are observed. In (II), weak C-H⋯O, bifurcated three-center inter-molecular inter-actions forming dimers along with weak C-H⋯π and π-π stacking inter-actions are observed, linking the mol-ecules into sheets along [001]. A weak C-H⋯Br intra-molecular inter-action is also present. There are no classical hydrogen bonds present in either structure.

Molecular structure, FT-IR, vibrational assignments, HOMO-LUMO, MEP, NBO analysis and molecular docking study of ethyl-6-(4-chlorophenyl)-4-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of ethyl-6-(4-chlorophenyl)-4-(4-fluoro-phenyl)-2-oxocyclohex-3-ene-1-carboxylate have been investigated experimentally and theoretically using Gaussian09 software. The title compound was optimized using the HF and DFT levels of theory. The geometrical parameters are in agreement with the XRD data. The stability of the molecule has been analyzed by NBO analysis. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. Molecular electrostatic potential was performed by the DFT method. As can be seen from the MEP map of the title compound, regions having the negative potential are over the electro negative atoms, the region having the positive potential are over the phenyl rings and the remaining species are surrounded by zero potential. First hyperpolarizability is calculated in order to find its role in non linear optics. The title compound binds at the active sites of both CypD and β-secretase and the molecular docking results draw the conclusion that the compound might exhibit β-secretase inhibitory activity which could be utilized for development of new anti-alzheimeric drugs with mild CypD inhibitory activity.

Ethyl 6-(4-chloro-phen-yl)-4-(4-fluoro-phen-yl)-2-oxo-cyclo-hex-3-ene-1-carboxyl-ate

The asymmetric unit of the title compound, C₂₁H₁₈ClFO₃, contains two independent mol­ecules. In one mol­ecule (A), the 4-chloro­phenyl, oxo­cyclo­hex-3-ene, carboxyl­ate, and ethyl groups were refined as disordered over two sets of sites with a 0.684 (5):0.316 (5) ratio. The cyclo­hexene ring in the disordered mol­ecule is in a slightly distorted envelope conformation for the major component (with the C atom bound to the carboxylate group being the flap atom) and in a screw-boat conformation for the minor component. In the ordered mol­ecule (B), the cyclo­hexene ring is in a half-chair conformation. The dihedral angles between the mean planes of the fluoro- and chloro-substituted benzene rings are 89.9 (7) (only the major component is considered for A) and 76.4 (7)° (B). In the crystal, inversion dimers are observed along with weak C—H⋯O hydrogen bonds, which form chains along [100].

1-(3-Bromo-2-thien-yl)ethanone

In the title compound, C(6)H(5)BrOS, the non-H and aromatic H atoms lie on a crystallographic mirror plane. In the crystal, mol-ecules are linked into chains propagating along the c axis by inter-molecular C-H⋯O hydrogen bonds.

Methyl 4,6-bis-(4-fluoro-phen-yl)-2-oxo-cyclo-hex-3-ene-1-carboxyl-ate

The 3-cyclo-hexene units adopt envelope conformations in each of the two independent mol-ecules that comprise the asymmetric unit of the title compound, C(20)H(16)F(2)O(3). The dihedral angles between the two fluoro-phenyl rings are 79.7 (2) and 73.7 (2)° in the two mol-ecules. In one of the mol-ecules, two C-H groups of the cyclo-hexene ring are disordered over two sets of sites in a 0.818 (13):0.182 (13) ratio, the major and minor components corresponding to the two enanti-omeric forms of the mol-ecule. Weak inter-molecular C-H⋯O inter-actions help to stabilize the crystal structure.