الفهرس 
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Abstract
The present study deals with the design, synthesis, molecular docking, and biological activity evaluation of new 4-(piperazin-1-yl)quinolin-2(1H)-ones bearing different aromatic and heteroaromatic moieties including anilines, thiazoles and some related Mannich bases. The target compounds were evaluated for their biological activities namely, anticancer, and antimicrobial activity. The cytotoxic activity on both cancer and normal cell lines was studied to assess both the efficacy and safety of active compounds. Molecular mechanism was studied for selected target compounds as VEGFR-2 inhibitory activity. Moreover, cell cycle analysis and apoptosis assay were carried out for the most active derivatives. Additionally, in silico studies of target interaction, pharmacokinetics, and bioavailability of synthesized derivatives were studied.
This thesis consists of five major parts: introduction, scope of investigation, results and discussion, experimental section, and references.
1- Introduction
The introduction is the first part of thesis that give an overview about anticancer and antimicrobial activity of quinoline derivatives. Herein, the introduction discusses mainly the role of quinoline derivatives as inhibitors of signaling pathways in cancer including activity against different kinases like EGFR, VEGFR, PDGFR, BCR-ABL, Src TKs, c-Met kinase, PI3k/AkT/mTOR, and Ras-Raf-MEK pathways. Also, the different literature antimicrobial activities of quinoline/thiazole hybrids were discussed.
2- Scope of investigation
This part represents the aim of work, including design and synthesis of novel 4-(piperazin-1-yl)quinolin-2(1H)-one derivatives with anticancer and VEGFR-2 inhibitory activities.
3- Results and discussion
This part includes details of all results obtained from different stages of study from the synthesis and structural elucidation to biological evaluation of the key intermediate compounds 4a,b and the final target compounds 6a-ah, 10a-h, and 11a-h.
This part is subdivided into four main sections:
The first one is Chemistry section which includes a description for the methods that used for the synthesis of intermediate compounds 4a,b as well as target compounds 6a-ah, 10a-h, and 11a-h and structural elucidations of the synthesized derivatives by different spectral investigations namely, 1H NMR, 13C NMR, and MS spectroscopy in addition to elemental analyses. In the present study, the synthesis of new fifty-two compounds were reported Scheme 1-4.
The second section is Biology that demonstrates different methods and results obtained from different biological investigations of the target compounds. It includes the following parts:
1. NCI evaluation of in vitro antiproliferative activity
The anticancer activity of key intermediate compounds 4a,b and the target compounds 6a-ah, 10a-h, and 11a-h were evaluated by NCI. Series I and II showed cytotoxic activity against T-47D and MDA-MB-468 breast cancer cell lines while Series III showed cytotoxic activity against EKVX NSCLC cell line.
2. Evaluation of in vitro cytotoxicity IC50 of selected compounds of Series I against breast cancer cell line
The cytotoxic activity of the compounds 6r-v, 6y, 6z, 6aa, 6ac, 6ad, 6ag, and 6ah was evaluated against T-47D cell. Nine out of twelve target compounds showed higher cytotoxic activity than Staurosporine namely, 6r, 6s, 6u, 6y, 6z, 6aa, 6ad, 6ag, and 6ah. Compound 6z with (R4 = 4-F) was the most potent agent with IC50 66 nM.
3. Evaluation of in vitro cytotoxicity IC50 of intermediates 4a,b and all compounds of series II against breast cancer cell line
The cytotoxic activity of synthesized compounds 4a,b and 10a-h were evaluated against T-47D breast cancer. Five out of eight target compounds showed higher cytotoxic activity than Staurosporine namely 10a, 10b, 10c, 10e and 10h. The dihalogenated derivative 10b with (R2 =F and R5 =Cl) displayed the highest cytotoxic activity with IC50 2.73 µM.
4. Evaluation of in vitro cytotoxicity IC50 of selected compounds of series III compounds against NSCLC cell line
The cytotoxic activity of the most active compounds in Series III was evaluated against EKVX NSCLC cell line. Three out of six target compounds showed higher cytotoxic activity than Staurosporine namely, 11c, 11d, and 11g. The triazol-1-ylmethyl derivative 11c (R2 =F) has the best cytotoxic activity with IC50 1.741 µM.
5. Evaluation of in vitro cytotoxicity IC50 against normal cell line
The cytotoxicity of compounds 6z, 10a, 10f, and 11d was evaluated against MCF 10A normal cell line. The tested compounds showed less cytotoxicity against MCF 10A cell line as compared to reference.
6. VEGFR-2 inhibitory assay
The inhibitory activity of selected compounds on VEGFR-2 TK was investigated. All compounds showed their inhibitory activity at nanomole range. Amongst Series I, compound 6z showed better enzyme inhibitory activity as compared to Sorafenib with IC50 38.76±1.7 nM. Amongst Series II, compounds 10a and 10d showed higher inhibitory activity than sorafenib with IC50 46.83±2.4 and 51.09±2.6, respectively. Amongst Series III, compound 11d showed the highest activity with IC50 63.77±2.8 nM.
7. Cell cycle analysis and apoptosis assay
The cell cycle analysis of compounds 6z, 10a, 10f, and 11d indicated that apoptosis was induced by tested compounds. Analysis of early and late apoptosis showed that tested compounds was able to induce significant levels of early and late apoptosis.
8. Evaluation of antimicrobial activity
The antimicrobial activity of intermediate compounds 4a,b and target compounds 6a-ah, 10a-h and 11a-h were evaluated in vitro against Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Tested compounds showed lower antibacterial activity against Gram negative strains than ciprofloxacin. They showed higher antibacterial activity than ciprofloxacin against Gram positive stain, S. aureus with compound 6b had the higher activity (MIC 1 mg/ml).
The third part is molecular modeling studies using MOE software. Docking simulation of target compounds was performed with co-crystalized VEGFR-2 protein with Sorafenib (PDB: 4ASD). Target compounds showed similar fitness to Sorafenib into active site of enzyme. Investigation of different poses of target compounds revealed their interactions with Cys919, Glu885 and Asp1046 residues which is in consistent with that of Sorafenib.
The last part is in silico physicochemical and pharmacokinetic prediction. All target compounds showed a high gastrointestinal absorption while Sorafenib showed low gastrointestinal absorption. Target compounds 10a-h does not pass blood brain barrier that confirming their good CNS safety profile. Synthesized compounds have higher Fraction Csp3 as compared to sorafenib.
4- Experimental section
The experimental section demonstrates the details of the methods and experiments used in this research and it includes the following four parts:
The first is chemistry which describes in detail the procedures used for synthesis of the intermediate compounds 4a,b and target compounds 6a-ah, 10a-h, and 11a-h. additionally, it includes all physical, spectroscopic, and elemental data of the synthesized compounds.
The second part is biology that illustrates the methodology of antimicrobial screening of synthesized compounds and evaluation of their cytotoxic activity against both cancer and normal cell line in addition to the procedures of VEGFR-2 enzyme inhibition evaluation and both cell cycle analysis and apoptosis assay.
The third part is the method of molecular modeling studies by using MOE software. The last one is methods in silico physicochemical and pharmacokinetic prediction by using SwissADME website.
5- References
Finally, this part involves the references of the chemical synthesis and biological evaluation of the synthesized compounds of this study.