الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Cancer is an enormous global health burden, touching every region and socioeconomic level. It is the second major cause of death worldwide exceeded only by heart disease, extensive efforts are being done in order to discover new treatments but despite advances in prevention and chemotherapeutic management, the disease still affects many millions of patients worldwide, and no complete cure has been discovered.
In this study, pyrazolopyrimidine derivatives have been designed and synthesized as targeted angiogenesis inhibitors. Our design focuses on exploration of the previous revealed SAR studies, bioisosteric modifications of the lead compounds both in market and in clinical studies, and Identification of the key interactions with the binding site in silico.
Synthesis of the designed compounds was then accomplished & their structures were confirmed by various spectral and microanalytical data.
The study involved the synthesis of the following reported unavailable intermediates:
Ethyl 5-amino-1-phenyl-1H-pyrazole-4-carboxylate (IIIa)
Ethyl 5-amino-1-(4-chlorophenyl)-1H-pyrazole-4-carboxylate (IIIb)
1-Phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (IVa)
1-p-Chlorophenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (IVb)
4-Chloro-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine (Va)
4-Chloro-1-p-chlorophenyl-1H-pyrazolo[3,4-d]pyrimidine (Vb)
1-(2-Chlorophenyl)-3-(4-nitrophenyl)urea (VIIIb)
1-(3-Chlorophenyl)-3-(4-nitrophenyl)urea (VIIIc)
1-(3-Bromophenyl)-3-(4-nitrophenyl)urea (VIIId)
1-(4-Nitrophenyl)-3-(o-tolyl)urea (VIIIe)
Abstract
XIV
1-(4-Aminophenyl)-3-(2-Chlorophenyl)urea (IXb)
1-(4-Aminophenyl)-3-(3-Chlorophenyl)urea (IXc)
1-(4-Aminophenyl)-3-(3-Bromophenyl)urea (IXd)
1-(4-Aminophenyl)-3-(o-tolyl)urea (IXe)
1-(4-Hydroxyphenyl)-3-phenylurea (XI)
3-(4-Chlorobenzyl)-6-nitrobenzo[d]thiazol-2(3H)-one (XIIIa)
3-(2,4-Dichlorobenzyl)-6-nitrobenzo[d]thiazol-2(3H)-one (XIIIb)
3-(3,4-Dichlorobenzyl)-6-nitrobenzo[d]thiazol-2(3H)-one (XIIIc)
3-(3-Bromobenzyl)-6-nitrobenzo[d]thiazol-2(3H)-one (XIIId)
6-Amino-3-(4-chlorobenzyl)benzo[d]thiazol-2(3H)-one (XIVa)
6-Amino-3-(2,4-dichlorobenzyl)benzo[d]thiazol-2(3H)-one (XIVb)
6-Amino-3-(3,4-dichlorobenzyl)benzo[d]thiazol-2(3H)-one (XIVc)
6-Amino-3-(3-bromobenzyl)benzo[d]thiazol-2(3H)-one (XIVd)
1-(Benzyloxy)-4-nitrobenzene (XVIIa)
1-Chloro-4-((4-nitrophenoxy)methyl)benzene (XVIIb)
4-(Benzyloxy)aniline (XVIIIa)
4-((4-Chlorobenzyl)oxy)aniline (XVIIIb)
4-Nitrobenzoyl chloride (XX)
N-Cyclohexyl-4-nitrobenzamide (XXIa)
N-(3-Chlorophenyl)-4-nitrobenzamide (XXIb)
N-(2-Chlorophenyl)-4-nitrobenzamide (XXIc)
N-(4-Chloro-3-(trifluoromethyl)phenyl)-4-nitrobenzamide (XXId)
4-Amino-N-cyclohexylbenzamide (XXIIa)
Abstract
XV
4-Amino-N-(3-chlorophenyl)benzamide (XXIIb)
4-Amino-N-(2-chlorophenyl)benzamide (XXIIc)
4-Amino-N-(4-chloro-3-(trifluoromethyl)phenyl)benzamide (XXIId)
Also, the study involved the synthesis and the characterization of the following new-targeted compounds:
1-(2-Chlorophenyl)-3-(4-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)phenyl)urea (XXIVa)
1-(3-Chlorophenyl)-3-(4-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)phenyl)urea (XXIVb)
1-(3-Bromophenyl)-3-(4-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)phenyl)urea (XXIVc)
1-(4-((1-(4-Chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)phenyl)-3-(o-tolyl)urea (XXIVd)
1-(2-Chlorophenyl)-3-(4-((1-(4-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)phenyl) urea (XXIVe)
1-Phenyl-3-(4-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)oxy)phenyl)urea (XXVa)
1-(4-((1-(4-Chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl)oxy)phenyl)-3-phenylurea (XXVb)
3-(4-Chlorobenzyl)-6-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)benzo[d]thiazol-2(3H)-one (XXVIa)
3-(3-Bromobenzyl)-6-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)benzo[d]thiazol-2(3H)-one (XXVIb)
3-(2,4-Dichlorobenzyl)-6-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)benzo[d]thiazol-2(3H)-one (XXVIc)
Abstract
XVI
3-(3,4-Dichlorobenzyl)-6-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)benzo[d]thiazol-2(3H)-one (XXVId)
6-((1-(4-Chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)-3-(2,4-dichlorobenzyl) benzo[d]thiazol-2(3H)-one (XXVIe)
N-(4-(Benzyloxy)phenyl)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine (XXVIIa)
N-(4-((4-Chlorobenzyl)oxy)phenyl)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine (XXVIIb)
N-(4-(Benzyloxy)phenyl)-1-(4-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine (XXVIIc)
N-(4-((4-Chlorobenzyl)oxy)phenyl)-1-(4-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine (XXVIId)
N-Cyclohexyl-4-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)benzamide (XXVIIIa)
N-(3-Chlorophenyl)-4-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)benzamide (XXVIIIb)
N-(4-Chloro-3-(trifluoromethyl)phenyl)-4-((1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)benzamide (XXVIIIc)
4-((1-(4-Chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)-N-cyclohexylbenzamide (XXVIIId)
N-(2-Chlorophenyl)-4-((1-(4-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl)amino)benzamide (XXVIIIe)
N-(4-Chloro-3-(trifluoromethyl)phenyl)-4-((1-(4-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl) amino) benzamide (XXVIIIf)
6-Methyl-N-(1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)benzo[d]thiazol-2-amine (XXIXa)
5,6-Dimethyl-N-(1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)benzo[d]thiazol-2-amine (XXIXb)
6-Chloro-N-(1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)benzo[d]thiazol-2-amine (XXIXc)
Abstract
XVII
6-Chloro-N-(1-(4-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl)benzo[d]thiazol-2-amine (XXIXd)
The percentage inhibitory activity of selected compounds on vascular endothelial growth factor receptor-2 (VEGFR-2) was performed in KINEXUS Corporation. Tested compounds displayed insignificant inhibitory activity.
The final compounds were submitted to National Cancer Institute (NCI), five of these compounds (XXVIa, XXVIIa, XXVIIc, XXVIIIa, and XXIXa) were selected for single dose screening program at 10 μM in the full NCI 60 cell panel. Compound XXVIIIa showed a distinctive pattern of selectivity on cell line panels. The tested derivative showed remarkable highest cell growth inhibition against non-small cell lung cancer HOP-62, CNS cancer SNB-75, breast cancer HS578T, and melanoma MALME-3M cell lines. The same compound XXVIIIa was further screened for 5-log dose range and it showed potent antiproliferative activity as its median growth inhibition GI50 equal to 1.71 μM against CNS cancer SNB-75 cell line.
COMPARE analysis was applied utilizing these values to calculate the Pearson product moment correlation coefficient (PCC); which illustrates a high correlation between compound XXVIIIa, with that of gefitinib which is well known selective epidermal growth factor receptor (EGFR) inhibitor, and orantinib (SU 6668) which are reported as an inhibitor of the receptor tyrosine kinases platelet derived growth factor receptor β (PDGFRβ), VEGFR-2, and fibroblast growth factor receptor 1 (FGFR1).
The rest of the synthesized compounds (XXIVa-e, XXVa,b, XXVIb-e, XXVIIb,d, XXVIIIb-f, and XXIXb-d) were screened for their cytotoxic activity against MCF-7 (breast) human tumor cell line. Compound (XXVIIIb) displayed the highest activity with IC50 equal to 1.12 μM.
In an attempt to investigate the potential molecular targets for the tested compounds on NCI 60 cell panel and MCF-7 human breast cell line, PharmMapper server was utilized to predict the biological targets of compounds. Three targets [C-MET, VEGFR-2, and mitogen-activated protein kinase (MAPK)] involved in cancer therapy, were found to be common between the selected compounds.
Abstract
XVIII
Based on COMPARE analysis and predictions of pharmmapper, the percentage inhibitory activity of selected compounds was evaluated on another seven tyrosine kinases (EGFR, Aurora-A, SRC, C-MET, PDGFR, MAPK (P38α), and HER-2).
Tested compounds displayed insignificant to weak inhibitory activity on these kinases. Compounds XXVIIIb, XXIVb, and XXVIa weakly inhibit EGFR, Aurora-A, and PDGFR kinases by 33, 28, and 24% respectively.
In addition, their weak inhibition was explained by docking studies using C-Docker algorithm (Accelrys Discovery studio 2.5software).
Also, computer aided ADMET study was performed using the software Accord for Excel (Accelrys Discovery studio 2.5software). Compound XXVIIIa showed medium penetration to the blood brain barrier, good absorption, low solubility, no hepatotoxicity, but it may inhibit cytochrome 450.
In conclusion, in this investigation, we have introduced a series of pyrazolo[3,4-d]pyrimidin derivatives as new potential antiproliferative compounds.