Synthesis and in vitro antitumor evaluation of new thieno[2,3-d]pyrimidine derivatives as EGFR and DHFR inhibitors.

New thienopyrimidine derivatives 2-16 have been synthesized and their in vitro cytotoxicity was evaluated against five different human cancer cell lines HCT-116, Hela, MDA-MB-231, MCF7 and PC3. Compounds 6e, 7a, 7b, 7d, 10c and 10e displayed the highest antitumor activity against all tested cell lines compared to Doxorubicin. Enzyme inhibition assay revealed that compounds 6e and 10e showed high inhibitory activity against EGFR-TK, with IC50 values of 0.133 and 0.151 µM, compared to Olmutinib (IC50 = 0.028 µM); while the highest DHFR inhibitory activity was shown by compounds 7d and 10e with IC50 values of 0.462 and 0.541 µM, compared to Methotrexate (IC50 = 0.117 µM). Cell cycle analysis following a flow cytometric study using colorectal HCT-116 cancer cell line proved that compound 6e induced cell cycle arrest in G0-G1 phase, while compound 10e arrested the cell cycle at both G0-G1 and S phases. Additionally, both compounds (6e and 10e) were potently able to induce apoptosis in HCT-116 cell line. Docking results of compounds 6e and 10e into the pocket of EGFR active site showed their similar main binding features with Olmutinib, while compounds 7d and 10e showed only moderate fitting into DHFR compared to methotrexate. In silico studies revealed that most of the tested compounds obeyed Lipinski's RO5 and showed positive drug likeness scores.

Synthesis, biological evaluation, and molecular modeling studies of new benzoxazole derivatives as PARP-2 inhibitors targeting breast cancer.

Many benzoxazole-based and similar scaffolds were reported to have wide-range of anticancer activities. In this study, four series of benzoxazole derivatives were designed by combining benzoxazole scaffold with different amines via a reversed phenyl amide linker to produce the compounds of series A, B and C. A fourth new hybrid of benzoxazole with 1,2,3 triazole ring (series D) was also designed. The designed compounds were synthesized and screened for their anti-breast cancer activity against MDA-MB-231 and MCF-7 cell lines using MTT assay. The most potent cytotoxic compounds; 11-14, 21, 22, 25-27 were further evaluated for their in vitro PARP-2 enzyme inhibition. Compounds 12 and 27 proved to be the most active PARP-2 inhibitors with IC50 values of 0.07 and 0.057 µM, respectively. Compounds 12 and 27 caused cell cycle arrest in mutant MCF-7 cell line at G2/M and G1/S phase, respectively and they possessed significant apoptosis-promoting activity. Docking results of compounds 12 and 27 into PARP-2 pocket demonstrated binding interactions comparable to those of olaparib. Their predicted pharmacokinetic parameters and oral bioavailability appeared to be appropriate. Collectively, it could be concluded that compounds 12 and 27 are promising anti-breast cancer agents that act as PARP-2 inhibitors with potent apoptotic activity.

Development of three ecological spectroscopic methods for analysis of betrixaban either alone or in mixture with lercanidipine: greenness assessment.

Three eco-friendly spectrophotometric methods were developed for determination of the novel anticoagulant drug, betrixaban (BTX). The first method (method A) was based on direct analysis of BTX at 229.4 nm on the zero-order spectrum using methanol as the optimum solvent. While the second method (method B) was based on measuring difference absorption value (ΔA) of BTX at 335 nm, which was obtained from pH-induced spectral difference (difference spectra of BTX in 0.1 M NaOH versus 0.1 M HCl). The third method (method C) was based on measurement of the first-derivative amplitudes of BTX and its co-administered Ca channel blocker lercanidipine (LER) at 304 and 229 nm for simultaneous assay of BTX and LER, respectively. All methods were linear over concentration ranges of 1.0-20.0 and 8.0-80.0 µg ml-1 for BTX in methods A and B, respectively, and of 1.0-20.0 and 1.0-25.0 µg ml-1 for BTX and LER, respectively, in method C. The three methods were fully validated and assessed for greenness by three metrics: analytical eco-scale, green analytical procedure index and Analytical GREEnness metrics. The results indicated the validity and greenness of the proposed methods. Moreover, the methods were applied to assay the studied analytes in their dosage forms with high percentage of recovery and low percentage of relative s.d. values.

Quantitative proton nuclear magnetic resonance method for simultaneous analysis of fluticasone propionate and azelastine hydrochloride in nasal spray formulation.

A facile, rapid, accurate and selective quantitative proton nuclear magnetic resonance (1H-qNMR) method was developed for the simultaneous determination of fluticasone propionate (FLP) and azelastine hydrochloride (AZH) in pharmaceutical nasal spray for the first time. The 1H-qNMR analysis of the studied analytes was performed using inositol as the internal standard and dimethyl sulfoxide-d6 (DMSO-d6) as the solvent. The quantitative selective proton signal of FLP was doublet of doublet at 6.290, 6.294, 6.316 and 6.319 ppm, while that of AZH was doublet at 8.292 and 8.310 ppm. The internal standard (inositol) produced a doublet signal at 3.70 and 3.71 ppm. The method was rectilinear over the concentration ranges of 0.25-20.0 and 0.2-15.0 mg ml-1 for FLP and AZH, respectively. No labelling or pretreatment steps were required for NMR analysis of the studied analytes. The proposed 1H-qNMR method was validated efficiently according to the International Council on Harmonisation guidelines in terms of linearity, limit of detection, limit of quantification, accuracy, precision, specificity and stability. Moreover, the method was applied to assay the analytes in their combined nasal spray formulation. The results ensured the linearity (r 2 > 0.999), precision (% RSD < 1.5), stability, specificity and selectivity of the developed method.

Optimization and Validation of a Facile RP-HPLC Method for Determination of Betrixaban and Lercanidipine in Pharmaceutical and Biological Matrices.

A simple, accurate, rapid and sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method was established for determination of a novel non-vitamin K antagonist oral anticoagulant drug, betrixaban, and its co-administered calcium-channel blocker drug, lercanidipine, in pharmaceutical formulations and biological fluids. The proposed HPLC method was the first chromatographic method applied to estimate this mixture in a short chromatographic run (<6 min), high resolution between betrixaban/lercanidipine (Rs = 7.12) and acceptable values of limit of detection (LOD), limit of quantification (LOQ) and percentage of relative standard deviation (%RSD). The chromatographic separation was performed on a cyano column using a mobile phase composed of acetonitrile:methanol:water (35:35:30, v/v/v) containing 0.2% orthophosphoric acid adjusted to pH 3.2 by triethylamine, programmed with a flow rate of 1 mL/min with UV detection at 240 nm. The proposed method showed linearity over the concentration ranges of (0.20-20.0 µg/mL) and (0.25-25.0 µg/mL) for betrixaban and lercanidipine, respectively. All validation parameters met the acceptance criteria according to ICH guidelines in terms of linearity, LOD, LOQ, accuracy, precision, robustness, specificity and system suitability. The method was applied to assay the studied analytes in their pharmaceutical formulations with high % recovery (98-102%) and low %RSD (<1.5). Furthermore, the proposed method was successfully applied for the determination of betrixaban in spiked human plasma.

New series of isoxazole derivatives targeting EGFR-TK: Synthesis, molecular modeling and antitumor evaluation.

New series of isoxazole derivatives were synthesized and evaluated for in vitro antitumor activity against HepG2, MCF-7 and HCT-116 cancer cells. Results showed that 4b and 25a are the most potent members against the three cancer cells (IC50 = 6.38-9.96 µM). Further, 4a, 8a and 16b showed strong activity against the three cancer cells, whereas 6b, 10a, 10b and 16a exhibited moderate activity against the three cancer cells. Moreover, 25a showed low cytotoxicity against WISH and WI38 normal cells (IC50 = 53.19 ± 3.1 and 38.64 ± 2.8 µM, respectively), and it might be used as a potent and safe antitumor agent. The nine active compounds 4a, 4b, 6b, 8a, 10a, 10b, 16a, 16b and 25a were studied for EGFR-TK inhibitory activity, where 10a, 10b and 25a showed the highest inhibitory activity (IC50 = 0.064 ± 0.001, 0.066 ± 0.001 and 0.054 ± 0.001 µM, respectively). Compound 25a was also assessed against other four target proteins, and it showed promising inhibitory activities against VEGFR-2, CK2α and topoisomerase IIß, and acceptable inhibitory activity against tubulin polymerization. Cell cycle analysis of cancer cells treated with 25a proved that it induces cell cycle arrest at G2/M and pre-G1 phases. Furthermore, it was confirmed that 25a induces cancer cell death through apoptosis, supported by increased caspases 3/9 levels and increased Bax/Bcl-2 ratio in the three cancer cells. In addition, docking studies proved the exact fit of 25a into the active site of EGFR-TK, VEGFR-2, CK2α, topoisomerase IIß and tubulin. Lipinski's rule and Veber's standards were also analyzed, and results illustrated that 25a is expected to be well absorbed orally.

Targeting hepatocellular carcinoma: Synthesis of new pyrazole-based derivatives, biological evaluation, DNA binding, and molecular modeling studies.

A new series of pyrazole derivatives was prepared in this work, including pyrazolopyrimidines, pyrazolotriazines, pyrazolylthienopyridines, and 2-(pyrazolylamino)thiazol-4-ones, utilizing 3-amino-5-methyl-1H-pyrazole as a synthetic precursor. Their in vitro anticancer activity was tested on hepatocellular carcinoma cell line, HepG2. The results revealed that the pyrazolylhydrazonoyl cyanide 8, the pyrazolopyrimidine 3, and the pyrazolylaminothiazolone 17 were the most active with IC50 values of 2, 7, and 7 µM respectively in comparison with 5.5 µM for cisplatin as a reference drug. Interestingly, all the synthesized compounds showed higher selectivity index than cisplatin. DNA binding assay was also carried out for the synthesized compounds to rationalize their mechanism of action. Molecular modeling studies, including docking into DNA minor groove, flexible alignment, and surface mapping, were conducted. Results obtained proved the superior DNA-binding affinity of the most active anticancer compounds.

Synthesis and in vitro antitumor evaluation of some new thiophenes and thieno[2,3-d]pyrimidine derivatives.

New thiophene (2-13) and thienopyrimidine (15-27) derivatives have been synthesized. Twenty three compounds were screened against five cell lines namely; hepatocellular carcinoma (liver) HepG-2, epidermoid carcinoma (larynx) Hep-2, mammary gland (breast) MCF-7, human prostate cancer PC-3 and epithelioid cervix carcinoma HeLa. The results revealed that compounds 15,16,17,24 and 25 showed the highest antitumor activity against all tested cell lines compared to Doxorubicin. In order to explain the expected mode of action of the observed anticancer activity, compounds 15,16,17,24 and 25 were selected to screen their DNA binding affinity and enzyme inhibitory activity against DNA polymerase, thymidylate synthase and tyrosine kinase. The results revealed that the tested compounds showed good DNA binding affinity as well as good inhibitory activity against the three enzymes which might explain the observed anticancer activity of the target compounds.

Design, synthesis, molecular modeling and biological evaluation of novel diaryl heterocyclic analogs as potential selective cyclooxygenase-2 (COX-2) inhibitors.

New series of 3,4-diaryl-2-thioxoimidazolidin-4-ones and 3-alkylthio-4,5-diaryl-4H-1,2,4-triazoles were designed, synthesized and evaluated for their activity as anti-inflammatory agents. Compounds 20, 21, 23 and 34 are highly selective inhibitors of COX-2 enzyme at a concentration of 100 mM relative to celecoxib, the standard reference. (±)-3-(4-Phenoxy-phenyl)-5-phenyl-2-thioxoimidazolidin-4-ones 23 exhibited the most active anti-inflammatory agent.

Synthesis, in vitro anticancer evaluation and in silico studies of novel imidazo[2,1-b]thiazole derivatives bearing pyrazole moieties.

A series of imidazo[2,1-b]thiazoles bearing pyrazole moieties 4-6(a-c) was synthesized through the reaction of 6-hydrazinylimidazo[2,1-b]thiazoles 3a-c with different ß-dicarbonyl compounds. Eleven compounds were screened at the National Cancer Institute (NCI), USA for anticancer activity at a single dose (10 µM). The in vitro anticancer evaluation revealed that compounds 2a and 4-6(a) exhibited increased potency towards CNS SNB-75 and Renal UO-31 cancer cell lines. COMPARE analyses showed strong to considerable correlations with rapamycin (mTOR inhibitor). The results of assessment of toxicities, druglikeness, and drug score profiles of compounds 2a and 4-6(a) are promising. Some of the target compounds showed good docking scores with potential anticancer targets, chosen based on pharmacophore mapping of the established derivatives.

Novel acetamidothiazole derivatives: synthesis and in vitro anticancer evaluation.

A novel series of acetamide derivatives possessing both 2-imino-4-arylthiazoles and morpholine or different piperazines were synthesized and characterized by IR, (1)H NMR, (13)C NMR, elemental and mass spectral analyses. Twelve compounds were granted NSC codes at National Cancer Institute (NCI), USA for anticancer activity at a single high dose (10(-5) M) in full NCI 60 cell panel. Among the compounds tested, compounds 5a and 6b were found to be the most active candidates of the synthesized series. Assessment of toxicities, druglikeness, and drug score profiles of compounds 5a and 6b are promising. Some of the synthesized compounds showed a good docking score with potential anticancer targets, chosen based on pharmacophore mapping of the established derivatives.

Synthesis, antimicrobial and anti-inflammatory activities of novel 5-(1-adamantyl)-1,3,4-thiadiazole derivatives.

New 1-adamanyl-1,3,4-thiadiazole derivatives namely, 5-(1-adamantyl)-1,3,4-thiadiazoline-2-thione 3, 5-(1-adamantyl)-3-(benzyl- or 4-substituted benzyl)-1,3,4-thiadiazoline-2-thione 4a-d, 5-(1-adamantyl)-3-(4-substituted-1-piperazinylmethyl)-1,3,4-thiadiazoline-2-thiones 5a-c, 2-[5-(1-adamantyl)-2-thioxo-1,3,4-thiadiazolin-3-yl]acetic acid 7, (±)-2-[5-(1-adamantyl)-2-thioxo-1,3,4-thiadiazolin-3-yl]propionic acid 9, 3-[5-(1-adamantyl)-2-thioxo-1,3,4-thiadiazolin-3-yl]propionic acid 11, N-[5-(1-adamantyl)-1,3,4-thiadiazol-2-yl]-N'-arylthioureas 15a-c and 5-(1-adamantyl)-1,3,4-thiadiazoline-2-one 16, were synthesized and tested for in vitro activities against a panel of gram-positive and gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Compounds 7, 9, 15b and 15c displayed marked activity against the tested gram-positive bacteria, while compound 3 was highly active against the tested gram-negative bacteria. Compounds 4b, 7 and 15c were weakly or moderately active against C. albicans. In addition, the in vivo anti-inflammatory activity of the synthesized compounds was determined using the carrageenan-induced paw oedema method in rats. The propionic acid derivative 9 produced good dose-dependent anti-inflammatory activity.

Synthesis, antimicrobial, and anti-inflammatory activities of novel 5-(1-adamantyl)-4-arylideneamino-3-mercapto-1,2,4-triazoles and related derivatives.

The reaction of 5-(1-adamantyl)-4-amino-3-mercapto-1,2,4-triazole (5) with various aromatic aldehydes in ethanol or acetic acid yielded the corresponding 4-arylideneamino derivatives 6a-v. Treatment of the 4-(2,6-difluoro- and dichlorobenzylideneamino) derivatives 6o and 6q with 1-substituted piperazines, and formaldehyde solution in ethanol afforded good yields of the corresponding 5-(1-adamantyl)-4-(2,6-dihalobenzylideneamino-2-(4-substituted-1-piperazinylmethyl)-1,2,4-triazoline-3-thiones 7a-p. 5-(1-Adamantyl)-4-arylideneamino-2-(4-ethoxycarbonyl-1-piperidylmethyl)-1,2,4-triazoline-3-thiones 8a-n, were similarly prepared via the reaction of the corresponding arylideneamino derivative with ethyl 4-piperidinecarboxylate and formaldehyde solution in ethanol. Compounds 6a-v, 7a-p and 8a-n were tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Several derivatives showed good or moderate activities, particularly against the tested Gram-positive bacteria. In addition, the in vivo anti-inflammatory activity of 21 compounds was determined using the carrageenan-induced paw oedema method in rats. Compounds 7d, 7g, 7i, 7j, 7l, 8c, 8e and 8l showed good or moderate dose-dependent activity in this area.