Chemistry
All melting points are uncorrected and were taken on electro-thermal capillary melting point apparatus. Infrared spectra were recorded on a Jasco FT/IR-6100, Fourier transforms, Infrared spectrometer (Japan) at cm-1 scale using the KBr disc technique in the Central Services Laboratory, National Research Center, Dokki, Cairo, Egypt. 1H NMR spectra were determined by using a JEOl EX-270 NMR spectrometer (Japan) at the Central Services Laboratory, National Research Center, Dokki, Cairo, Egypt. The mass spectra were measured with a Finnigan MAT SSQ-7000 mass spectrometer at the Central Services Laboratory, Cairo University, Giza, Egypt. Follow up of the reactions and checking the purity of the compounds were made by TLC on silica gel-precoated aluminum sheets (Type 60, F 254, Merck, Darmstadt, Germany) and the spots were detected by exposure to UV analysis lamp at λ 254/366 nm for few seconds.
General procedure for the preparation of compounds (3a, c, d)
A solution of acid chloride (2a, c, d) (0.01 mol) and anthranilic acid (0.01 mol) in dry pyridine (30 mL) was refluxed for 3 h, the reaction mixture was cooled and poured into cold diluted HCl. The precipitate was collected by filtration and recrystallized from a proper solvent to give (3a, c, d). Spectroscopic data for all the compounds are given below.
2-(Pyridin-3-yl)-4H-3, 1-benzoxazin-4-one (3a)
Yield 80%. Yellow, white crystals. mp. 210-217 ˚C, IR (KBr, cm-1): 1700 (C = O). 1H NMR (DMSO-d6, δ ppm): 7.50-9.03 (m, 8H, aromatic). MS: (m/z) ≈ 224 (10%). Anal. Calcd for C13H8N2O2 (224.21): C, 69.64; H, 3.60; N, 12.49%. Found: C, 69.43; H, 3.44; N, 12.14%.
2-(Pyridin-4-yl)-4H-3, 1-benzoxazin-4-one (3c)
Yield 85%. Yellow crystals. mp >300 ˚C, IR (KBr, cm-1): 1692 (C = O). 1H NMR (DMSO-d6, δ ppm): 7.42-9.21 (m, 8H, aromatic). MS: (m/z) ≈ 224 (15%). Anal. Calcd for C13H8N2O2 (224.21): C, 69.64; H, 3.60; N, 12.49%. Found: C, 69.55; H, 3.51; N, 12.25%.
2-[2-(Phenylamino) phenyl]-4H-3, 1-benzoxazin-4-one (3d)
Yield 85%. Yellow crystals. mp. 235-240 ˚C, IR (KBr, cm-1): 1690 (C = O) and 3170 (NH). 1H NMR (DMSO-d6, δ ppm): 7.20-8.20 (m, 13H, aromatic), 11.72 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 314 (5%). Anal. Calcd for C20H14N2O2 (314.33): C, 76.42; H, 4.49; N, 8.91%. Found: C, 76.03; H, 4.20; N, 8.34%.
General procedure for the preparation of compounds (4a, b)
A mixture of (3a (
44), 3b (
45)) (0.01 mol) and formamide (0.015 mol) was refluxed for 3 h in boiling ethanol (30 mL), then poured into water. The precipitated solid after concentration and cooling was collected by filtration and crystallized from the proper solvent to give (4a, b). Spectroscopic data for all the compounds are given below.
2-(Pyridin-3-yl) quinazolin-4 (3H)-one (4a):
Yield 65%, White crystals. mp. >300 ˚C, IR (KBr, cm-1): 1700 (C = O) and 3299 (NH). 1H NMR (DMSO-d6, δ ppm): 7.23-8.32 (m, 8H, aromatic), 12 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 223 (0.13%). Anal. Calcd for C13H9N3O (223.23): C, 69.95; H, 4.06; N, 18.82%. Found: C, 69.62; H, 3.88; N, 18.60%.
2-[(E)-2-(furan-2-yl) ethenyl] quinazolin-4 (3H)-one (4b)
Yield 85%. Black crystals. mp. 170-175 ˚C, IR (KBr, cm-1): 1698 (C = O) and 3150 (NH). 1H NMR (DMSO-d6, δ ppm): 6.48 (d, J = 5.4 Hz, 1H, CH), 6.89 (d, J = 2.7 Hz, 1H, CH), 7.11-8.59 (m, 7H, aromatic), 11.78 (s, 1H, NH, exchangeable with D2O).MS: (m/z) ≈ 238 (10%). Anal. Calcd for C14H10N2O2 (238.24): C, 70.58; H, 4.23; N, 11.76%. Found: C, 70.30; H, 4.08; N, 11.50%.
General procedure for the preparation of compounds (5a, b)
A mixture of (4a, b) (0.01 mol) and chloroacetyl chloride (0.01 mol) was refluxed in boiling N, N-dimethylformamide (DMF) (30 mL) for 3 h. Then the mixture was poured into water. The precipitate was collected by filtration, dried and crystallized from the proper solvent to give (5a, b). Spectroscopic data for all the compounds are given below.
3-(Chloroacetyl)-2-(pyridin-3-yl) quinazolin-4 (3H)-one (5a)
Yield 80%. Gray crystals. mp. >300 ˚C, IR (KBr, cm-1): 1650 (C = O) and 1690 (C = O). 1H NMR (DMSO-d6, δ ppm): 4.48 (s, 2H, CH2), 7.63-9.07 (m, 8H, aromatic). MS: (m/z) ≈ 299 (6%), [M + 2]+ m/z ≈ 301 (3%). Anal. Calcd for C15H10ClN3O2 (299.71): C, 60.11; H, 3.36; N, 14.02%. Found: C, 59.90; H, 2.98; N, 13.90%.
3-(Chloroacetyl)-2-[(E)-2-(furan-2-yl) ethenyl] quinazolin-4 (3H)-one (5b)
Yield 90%. Black crystals. mp. 151-155 ˚C, IR (KBr, cm-1): 1690 (C = O) and 1710 (C = O). 1H NMR (DMSO-d6, δ ppm): 4.90 (s, 2H, CH2), 6.23 (d, J = 8.1 Hz, 1H, CH), 6.70 (d, J = 5.4 Hz, 1H, CH), 6.95-8.21 (m, 7H, aromatic). MS: (m/z) ≈ 314 (1.8%), [M+2] + m/z ≈ 316 (1%). Anal. Calcd for C16H11ClN2O3 (314.72): C, 61.06; H, 3.52; N, 8.90%. Found: C, 60.90; H, 3.30; N, 8.67%.
General procedure for the preparation of compounds (6a, b)
A mixture of (5a, b) (0.01 mol) and hydrazine hydrate (0.015 mol) was heated in boiling ethanol (30 mL) under reflux for 4 h. Then the mixture was poured into water. The precipitate was collected by filtration, dried and crystallized from the proper solvent to give (6a, b). Spectroscopic data for all the compounds are given below.
3-(Hydrazinylacetyl)-2-(pyridin-3-yl) quinazolin-4 (3H)-one (6a)
Yield 75%. Gray crystals. mp. 106-110 ˚C, IR (KBr, cm-1): 1690, 1700 (2C = O), 3190 (NH) and 3300-3444 (NH2). 1H NMR (DMSO-d6, δ ppm): 3.55 (s, 2H, CH2), 3.80 (s, 2H, NH2, exchangeable with D2O), 7.58-9.07 (m, 8H, aromatic), 10.49 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 295 (12%). Anal. Calcd for C15H13N5O2 (295.29): C, 61.01; H, 4.44; N, 23.72%. Found: C, 60.85; H, 4.20; N, 23.50%.
2-[(E)-2-(furan-2-yl) ethenyl]-3-(hydrazinylacetyl) quinazolin-4 (3H)-one (6b)
Yield 65%. White crystals. mp. > 300 ˚C, IR (KBr, cm-1): 1687, 1697 (2C = O), 3174 (NH) and 3320-3400 (NH2). 1H NMR (DMSO-d6, δ ppm): 3.49 (s, 2H, CH2), 3.70 (s, 2H, NH2, exchangeable with D2O), 6.65, 6.90 (2d, J = 5.4 Hz, J = 2.7 Hz, 2H, 2CH), 7.01-8.48 (m, 7H, aromatic), 11.21 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 310 (3%). Anal. Calcd for C16H14N4O3 (310.30): C, 61.93; H, 4.55; N, 18.06%. Found: C, 61.70; H, 4.35; N, 17.80%.
General procedure for the preparation of compounds (7c, d)
A solution of (3c, d) (44) (0.01 mol) in dry benzene (30 mL) and hydrazine hydrate (0.015 mol) was heated under reflux for 4 h. Then the mixture was poured into water. The precipitate was collected by filtration, dried and crystallized from the proper solvent to give (7c, d) (44). Spectroscopic data for all the compounds are given below.
3-Amino-2-(pyridin-4-yl) quinazolin-4 (3H)-one (7c)
Yield 75%, Black crystals. mp. 150-155 ˚C, IR (KBr, cm-1): 1685 (C = O) and 3311-3420 (NH2). 1H NMR (DMSO-d6, δ ppm): 7.68-8.66 (m, 8H, aromatic), 10.08 (s, 2H, NH2, exchangeable with D2O). MS: (m/z) ≈ 238 (15%). Anal. Calcd for C13H10N4O (238.24): C, 65.54; H, 4.23; N, 23.52%. Found: C, 65.32; H, 4.18; N, 23.40%.
3-Amino-2-[2-(phenylamino) phenyl] quinazolin-4 (3H)-one (7d)
Yield 85%. Yellow crystals. mp. 260-265 ˚C, IR (KBr, cm-1): 1700 (C = O), 3172 (NH) and 3300-3434 (NH2). 1H NMR (DMSO-d6, δ ppm): 3.60 (s, 2H, NH2, exchangeable with D2O), 6.68-8.54 (m, 13H, aromatic), 12.01 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 328 (20%). Anal. Calcd for C20H16N4O (328.36): C, 73.15; H, 4.91; N, 17.06%. Found: C, 73.01; H, 4.75; N, 16.90%.
General procedure for the preparation of compounds (8c, d)
A solution of (7c, d) (44) (0.01 mol), was allowed to react with chloroacetyl chloride (0.01 mol) in refluxing pyridine about 2 h, and then poured over ice/HCl. The precipitate was collected by filtration and crystallized from the proper solvent to give (8c, d). Spectroscopic data for all the compounds are given below.
2-Chloro-N-[4-oxo-2-(pyridin-4-yl) quinazolin-3 (4H)-yl] acetamide (8c)
Yield 70%. Yellow crystals. mp. > 300 ˚C, IR (KBr, cm-1): 1698, 1715 (2C = O) and 3175 (NH). 1H NMR (DMSO-d6, δ ppm): 4.78 (s, 2H, CH2), 7.65-8.44 (m, 8H, aromatic), 11.87 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 314 (8%), [M + 2] + m/z ≈ 316 (4%). Anal. Calcd for C15H11ClN4O2 (314.72): C, 57.24; H, 3.52; N, 17.80%. Found: C, 57.12; H, 3.40; N, 17.60%.
2-Chloro-N-{4-oxo-2-[2-(phenylamino) phenyl] quinazolin-3 (4H)-yl} acetamide (8d)
Yield 75%. Black crystals. mp. 190-195 ˚C, IR (KBr, cm-1): 1677, 1690 (2C = O) and 3230 (NH). 1H NMR (DMSO-d6, δ ppm): 4.90 (s, 2H, CH2), 6.81-8.20 (m, 13H, aromatic), 11.90, 12 (2s, 2H, 2NH, exchangeable with D2O). MS: (m/z) ≈ 404 (23%), [M + 2] + m/z ≈ 406 (15%). Anal. Calcd for C22H17ClN4O2 (404.84): C, 65.27; H, 4.23; N, 13.84%. Found: C, 65.05; H, 4.18; N, 13.75%.
General procedure for the preparation of compounds (9c, d)
A solution of compounds (7c, d) (44) (0.01 mol) and chloroacetamide (0.015 mol) was refluxed for 3 h in boiling N, N-dimethylformamide (DMF) (30 mL). Then the mixture was poured into water. The precipitate was collected by filtration, dried and crystallized from the proper solvent to give (9c, d). Spectroscopic data for all the compounds are given below.
6-(Pyridin-4-yl)-3, 4-dihydro-2H-[1, 2, 4] triazino [2, 3-c] quinazolin-2-one (9c)
Yield 65%. Black crystals. mp. > 300 ˚C, IR (KBr, cm-1): 1710 (C = O) and 3189 (NH). 1H NMR (DMSO-d6, δ ppm): 3.76 (s, 2H, CH2), 7.33-8.66 (m, 8H, aromatic), 10.70 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 277 (13%). Anal. Calcd for C15H11N5O (277.28): C, 64.97; H, 4.00; N, 25.26%. Found: C, 64.70; H, 3.88; N, 25.07%.
6-[2-(Phenylamino) phenyl]-3, 4-dihydro-2H-[1, 2, 4] triazino [2, 3-c] quinazolin-2-one (9d)
Yield 85%. Yellow crystals. mp. 256-260 ˚C, IR (KBr, cm-1): 1677 (C = O) and 3150 (NH). 1H NMR (DMSO-d6, δ ppm): 3.65 (s, 2H, CH2), 6.87-7.96 (m, 13H, aromatic), 10.70, 11.30 (2s, 2H, 2NH, exchangeable with D2O). MS: (m/z) ≈ 367 (19%). Anal. Calcd for C22H17N5O (367.40): C, 71.92; H, 4.66; N, 19.06%. Found: C, 71.76; H, 4.49; N, 18.89%.
General procedure for the preparation of compounds (10c, d)
A solution of compounds (7c, d) (
44) (0.01 mol) and phenyl isothiocyanate (0.01 mol) was refluxed in boiling benzene (30 mL) for 3 h, then concentrated and crystallized from the proper solvent to give (10c, d). Spectroscopic data for all the compounds are given below.
1-[4-Oxo-2-(pyridin-4-yl) quinazolin-3 (4H)-yl]-3-phenylthiourea (10c)
Yield 90%. White crystals. mp. 195-200 ˚C, IR (KBr, cm-1): 1685 (C = O) and 3190 (NH). 1H NMR (DMSO-d6, δ ppm): 7.33-8.96 (m, 13H, aromatic), 10.49, 11.01 (2s, 2H, 2NH, exchangeable with D2O). MS: (m/z) ≈ 373 (5%). Anal. Calcd for C20H15N5OS (373.43): C, 64.33; H, 4.05; N, 18.75%. Found: C, 64.12; H, 3.90; N, 18.50%.
1-(4-Oxo-2-(2-(phenylamino) phenyl) quinazolin-3 (4H)-yl)-3-phenylthiourea (10d)
Yield 80%. Yellow crystals. mp. 200-205 ˚C, IR (KBr, cm-1): 1700 (C = O) and 3200 (NH). 1H NMR (DMSO-d6, δ ppm): 7.09-8.24 (m, 18H, aromatic), 9.77, 9.86, 11.70 (3s, 3H, 3NH, exchangeable with D2O). MS: (m/z) ≈ 463 (3%). Anal. Calcd for C27H21N5OS (463.55): C, 69.96; H, 4.57; N, 15.11%. Found: C, 69.69; H, 4.48; N, 14.90%.
General procedure for the preparation of compounds (11c, d)
A solution of (7c, d) (
44) (0.01 mol) and benzoyl chloride (0.01 mol) in dry acetone (30 mL) was refluxed for 3 h. Excess solvent was removed and The precipitated solid obtained was crystallized from suitable solvent to obtain (11c, d). Spectroscopic data for all the compounds are given below.
N-[4-oxo-2-(pyridin-4-yl) quinazolin-3 (4H)-yl] benzamide (11c)
Yield 70%. Yellow crystals. mp. 180-185 ˚C, IR (KBr, cm-1): 1677, 1690 (2C = O) and 3150 (NH). 1H NMR (DMSO-d6, δ ppm): 7.31-8.42 (m, 13H, aromatic), 12.01 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 342 (17%). Anal. Calcd for C20H14N4O2 (342.35): C, 70.17; H, 4.12; N, 16.37%. Found: C, 70.02; H, 3.90; N, 16.17%.
N-(4-oxo-2-(2-(phenylamino) phenyl) quinazolin-3 (4H)-yl) benzamide (11d)
Yield 80%. Yellow crystals. mp. > 300 ˚C, IR (KBr, cm-1): 1687, 1693 (2C = O) and 3177 (NH). 1H NMR (DMSO-d6, δ ppm): 7.16-8.45 (m, 18H, aromatic), 11.01, 12.01 (2s, 2H, 2NH, exchangeable with D2O). MS: (m/z) ≈ 432 (10%). Anal. Calcd for C27H20N4O2 (432.47): C, 74.98; H, 4.66; N, 12.95%. Found: C, 74.70; H, 4.50; N, 12.80%.
General procedure for the preparation of compounds (12c, d)
A solution of (11c, d) (0.01 mol) with ammonium acetate (0.01 mol) in acetic acid (30 mL) was heated under reflux for 3 h, then poured into water. The precipitated solid after concentration and cooling was collected by filtration and crystallized from suitable solvent to give (12c, d). Spectroscopic data for all the compounds are given below.
2-Phenyl-5-(pyridin-4-yl) [1, 2, 4] triazolo [1, 5-c] quinazoline (12c)
Yield 65%. Gray crystals. mp. 215-220 ˚C, 1H NMR (DMSO-d6, δ ppm): 7.41-8.75 (m, 13H, aromatic). MS: (m/z) ≈ 323 (33%). Anal. Calcd for C20H13N5 (323.35): C, 74.29; H, 4.05; N, 21.66%. Found: C, 74.11; H, 3.89; N, 21.56%.
N-phenyl-2-(2-phenyl-[1, 2, 4] triazolo [1, 5-c] quinazolin-5-yl) aniline (12d)
Yield 85%. Yellow crystals. mp. 240-245 ˚C, IR (KBr, cm-1): 3177 (NH). 1H NMR (DMSO-d6, δ ppm): 6.69-8.28 (m, 18H, aromatic), 13 (s, 1H, NH, exchangeable with D2O). MS: (m/z) ≈ 413 (11%). Anal. Calcd for C27H19N5 (413.47): C, 78.43; H, 4.63; N, 16.94%. Found: C, 78.22; H, 4.48; N, 16.80%.
Cytotoxic effect on human cell line (HePG2 – MCF 7 - A549)
Cell viability was assessed by the mitochondrial dependent reduction of yellow MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) to purple formazan (
46).
Procedure: All the following procedures were done in a sterile area using a Laminar flow cabinet biosafety class II level (Baker, SG403INT, Sanford, ME, USA). Cells were suspended in RPMI 1640 medium for HePG2- MCF7 and DMEM for A549. The media are supplemented with 1% antibiotic-antimycotic mixture (10,000 U/mL Potassium Penicillin, 10,000 µg/mL Streptomycin Sulfate and 25 µg/mL Amphotericin B), 1% L-glutamine and 10% fetal bovine serum and kept at 37 ºC under 5% CO2.
Cells were batch cultured for 10 days, then seeded at concentration of 10x10
3 cells/well in fresh complete growth medium in 96-well Microtiter plastic plates at 37 ˚C for 24 h under 5% CO
2 using a water jacketed Carbon dioxide incubator (Sheldon, TC2323, Cornelius, OR, USA). Media was aspirated, fresh medium (without serum) was added and cells were incubated either alone (negative control) or with different concentrations of sample to give a final concentration of (100-50-25-12.5-6.25-3.125-0.78 and 1.56 µg/mL). After 48 h of incubation, the medium was aspirated, 40 µL MTT salt (2.5 μg/mL) were added to each well and incubated for a further four hours at 37 ºC under 5% CO
2. To stop the reaction and dissolving the formed crystals, 200 μL of 10% Sodium dodecyl sulphate (SDS) in deionized water was added to each well and incubated overnight at 37 ºC. A positive control which composed of 100 µg/mL was used as a known cytotoxic natural agent who gives 100% lethality under the same conditions (
47,
48).
The absorbance was then measured using a microplate multi-well reader (Bio-Rad Laboratories Inc., model 3350, Hercules, California, USA) at 595 nm and a reference wavelength of 620 nm. A statistical significance was tested between samples and negative control (cells with vehicle) using independent t-test by SPSS 11 program. DMSO is the vehicle used for dissolution of plant extracts and its final concentration in the cells was less than 0.2%. The percentage of change in viability was calculated according to the formula:
(Reading of extract/Reading of negative control)-1) x 100. A probit analysis was carried for IC50 and IC90 determination using SPSS 11 program.
Molecular docking study
All docking studies were performed using "Internal Coordinate Mechanics" (Molsoft ICM 3.5-0a).
Preparation of small molecule
Compounds 2d, 3a, 3b, 3d, 4a, 4b, 5a, 5b, 6a, 6b, 7c, 7d, 8d, 9c, 9d, 10c, 10d, 11c, 11d, 12c, 12d were built in Chem Draw Ultra version 11.0 and their energy minimized through Chem3D Ultra version 11.0/MM2, Jop Type: minimum RMS Gradient of 0.100, and saved as MDL Mol File (*.Mol).
Generation of Ligand and Enzyme Structures
The crystal structures of EGFR (PDB code: 1M17) complex were retrieved from the RCSB Protein Data Bank (http://www.rcsb.org/pdb/ home/home.do).
We inspect the quality of the PDB file that was used using the PROSESS (Protein Structure Evaluation Suite & Server) (
http://www.prosess.ca/) (
Figure 1,
2). In our investigation, the 3D-coordinates in X-ray crystal structure of EGFR in complex with the ligand, Erlotinib (PDB entry 1M17) was used as the receptor model in EGFR docking simulation (
Figure 3). All bound waters ligands and cofactors were removed from the protein.
Quality of the PDB file that was used using the Prosess
Quality of the PDB file that was used using the Prosess
Binding model of erlotinib in to active pocket of EGFR receptor
Docking using Molsoft ICM 3.5-0 a program
The conversion of our PDB file into an ICM object involves the addition of hydrogen bonds, assignment of atom types, and charges from the residue templates, then perform ICM small molecule docking through setup the receptor, review and adjust binding site makes receptor maps, then start docking simulation, followed by displaying the results. ICM stochastic global optimization algorithm attempts to find the global minimum of the energy function that include five grid potentials describing the interaction of the flexible ligand with the receptor and internal conformational energy of the ligand, during this process a stack of alternative low energy conformations is saved. All inhibitors were compared according to the best binding free energy (minimum) obtained among all the run.