Vibrational spectroscopic and molecular docking study of 4-Methylphenylquinoline-2-carboxylate.

FT-IR and FT-Raman spectra of 4-Methylphenylquinoline-2-carboxylate were recorded and analyzed. The structure of the molecule has been optimized and structural characteristics have been determined by density functional theory. The geometrical parameters (DFT) are in agreement with the XRD results. HOMO and LUMO and other chemical properties are reported. Nonlinear optical properties are also reported. A detailed molecular picture of the title compound and its interactions were obtained from NBO analysis. The negative (red and yellow) regions of the MEP are related to electrophilic reactivity and the positive (blue) regions to nucleophilic reactivity, as shown in the MEP plot and the carbonyl group and the phenyl rings are observed as electrophilic. PASS analysis predicts that the 4-Methylphenylquinoline-2-carboxylate might exhibit anti-diabetic activity. Molecular docking results suggest that the compound might exhibit inhibitory activity against GPb.

Spectroscopic investigation (FT-IR, FT-Raman), HOMO-LUMO, NBO analysis and molecular docking study of 4-chlorophenyl quinoline-2-carboxylate.

FT-IR and FT-Raman spectra of 4-chlorophenyl quinoline-2-carboxylate were recorded and analyzed. The vibrational wavenumbers were computed using DFT quantum chemical calculations. The data obtained from wavenumber calculations are used to assign vibrational bands obtained experimentally. Potential energy distribution was done using GAR2PED program. The geometrical parameters obtained theoretically are in agreement with the XRD data. NBO analysis, HOMO-LUMO, first hyperpolarizability and molecular electrostatic potential results are also reported. The calculated hyperpolarizability of the title compound is 77.53 times that of the standard NLO material urea and the title compound and its derivatives are attractive object for future studies of nonlinear optical properties. Molecular docking results suggest that the compound might exhibit inhibitory activity against GPb.

2,5-Di-methyl-phenyl quinoline-2-carboxy-l-ate.

In the title compound, C18H15NO2, the dihedral angle between the mean planes of the quinoline ring system and the phenyl ring is 78.8 (1)°. The mean plane of the carboxyl-ate group is twisted from the mean planes of the quinoline ring system and phenyl ring by 1.5 (9) and 77.6 (4)°, respectively. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions, generating C(8) chains along [001]. Weak π-π stacking inter-actions are also observed [centroid-centroid separation = 3.6238 (12) Å].

2-Isopropyl-5-methyl-cyclo-hexyl quinoline-2-carboxyl-ate.

In the title compound, C20H25NO2, the cyclo-hexyl ring adopts a slightly disordered chair conformation. The dihedral angle between the mean planes of the quinoline ring and the carboxyl-ate group is 22.2 (6)°. In the crystal, weak C-H⋯N inter-actions make chains along [010].

4-Chloro-phenyl quinoline-2-carboxyl-ate.

In the title compound, C16H10ClNO2, the dihedral angle between the quinoline ring system and the benzene ring is 14.7 (5)°. The carboxyl-ate group is twisted from the mean planes of the quinoline ring system and the benzene ring by 17.7 (5) and 32.1 (4)°, respectively. In the crystal, inversion dimers are formed with the molecules linked by pairs of weak C-H⋯O inter-actions arising from an activated aromatic C atom adjacent to the C-Cl bond, generating R 2 (2)(14) loops.

4-Chloro-3-methyl-phenyl quinoline-2-carboxyl-ate.

In the title compound, C17H12ClNO2, the dihedral angle between the mean planes of the quinoline ring system and the benzene ring is 68.7 (7)°. The mean plane of the carboxyl-ate group is twisted from the latter planes by 14.0 (1) and 80.2 (4)°, respectively. In the crystal, weak C-H⋯O inter-actions are observed, forming chains along [001]. In addition, π-π stacking inter-actions [centroid-centroid distances = 3.8343 (13) and 3.7372 (13)Å] occur. No classical hydrogen bonds were observed.

3,4-Di-methyl-phenyl quinoline-2-carboxyl-ate.

In the title compound, C18H15NO2, the dihedral angle between the mean planes of the quinoline ring system and the phenyl ring is 48.1 (5)°. The mean plane of the carboxyl-ate group is twisted from the mean planes of the latter by 19.8 (8) and 64.9 (5)°, respectively. The crystal packing features weak C-H⋯O inter-actions, which form chains along [010].

4-Methyl-phenyl quinoline-2-carboxyl-ate.

In the title compound, C(17)H(13)NO(2), two mol-ecules crystallize in the asymmetric unit. The dihedral angle between the mean planes of the quinoline and benzene rings are 78.3 (4) and 88.2 (3)°. The carboxyl-ate group is twisted slightly from the quinoline ring by 7.1 (2) and 13.3 (4)°, respectively. In the crystal, weak C-H⋯O inter-actions are observed. Further stabilization is provided by weak π-π stacking inter-actions, with centroid-centroid distances of 3.564 (9)/3.689 (2) and 3.830 (1)/3.896 (5)Å, respectively.

Modulation of tramadol release from a hydrophobic matrix: implications of formulations and processing variables.

In the present investigation, hydrogenated cottonseed oil (HCSO) was evaluated as a sustained release matrix for a freely soluble drug, tramadol. Hydrophobic matrix tablets of tramadol, was evaluated by compression of physical mixture of drug and wax, dispersion of drug in HCSO by hot fusion or solubilisation techniques. The method of preparation of tablet had a significant effect on drug release with higher release observed from direct compression matrices and slower release from matrix prepared by dispersion (hot-fused matrices). Influence of addition of hydroxypropylmethyl cellulose, sodium carboxymethyl cellulose, polyethylene glycol 4000 and surfactants like sodium lauryl sulphate and polysorbate 20 to HCSO matrix on drug release was investigated. The added excipients exhibited a propensity to enhance drug release from the HCSO matrix. NaCMC was effective at a lower ratio (<10% w/w) and when incorporated at higher level made HCSO matrix to erode and disintegrate in a short period.