Novel quinoxaline-based VEGFR-2 inhibitors to halt angiogenesis.

Vascular endothelial growth factor receptor-2 is a dynamic target for therapeutic intervention in various types of cancer. This study was aimed at exploring the VEGFR-2 inhibitory activity of a novel library of quinoxalin-2-one derivatives such as 3-furoquinoxaline carboxamides, 3-pyrazolylquinoxalines, and 3-pyridopyrimidyl-quinoxalines. Among them, 6c, 7a, and 7d-f produced remarkable cytotoxicity against HCT-116 (IC50's 4.28-9.31 µM) and MCF-7 (IC50's 3.57-7.57 µM) cell lines using the MTT assay and doxorubicin (DOX) as a reference standard. Interestingly, results of cytotoxicity towards the human fibroblast cell line WI38 revealed that these hits demonstrated higher selectivity indices towards both HCT-116 (SI 8.69-23.19) and MCF-7 (SI 9.48-27.80) than DOX, SI 0.72 and 0.90, respectively. Then, these hits were subjected to a mechanistic study; they showed direct inhibition of VEGFR-2. Impressively, compound 7f displayed 1.2 times the VEGFR-2 inhibitory activity of sorafenib. The antiangiogenic potential of 7f was proved via lowering the level of VEGF-A, than that of control. It as well, exhibited scratch closure percent of 61.8%, compared with 74.5% of control at 48 hrs, indicating the potential anti-migratory effect of the compound 7f. It significantly increased the expression of tumor suppressor gene (p53) on MCF-7 cells by almost 18 folds and upregulated the caspase-3 level by 10.7 folds, compared to the control. Cell cycle analysis revealed cell cycle arrest at G2/M together with a PreG increase which indicated apoptosis induction potential. Annexin V-FITC apoptosis results proposed the two modes of cell death (apoptosis and necrosis) as an inherent mechanism of cytotoxicity of compound 7f. Molecular docking further supported the mechanism showing the affinity of target compounds for VEGFR-2 active site. Moreover, physicochemical and drug-like properties were assessed from the ADME properties.

Design, synthesis, anticancer evaluation and docking studies of new pyrimidine derivatives as potent thymidylate synthase inhibitors.

Cancer is a perplexing and challenging problem for researchers. In this study, a series of 6-aryl-5-cyano-pyrimidine derivatives were designed, synthesized and evaluated for their anticancer activity against HePG-2, MCF-7 and HCT-116 cell lines. Compounds 2, 3d, 4a-c, 5, 8 and 12 displayed high anticancer activity, comparable to that of 5-fluorouracil. Additionally, those compounds with effective anticancer activity were further assessed for their ability to inhibit thymidylate synthase (TS) enzyme. All the tested compounds demonstrated a marked TS inhibitory activity (33.66-74.98%), with IC50 ranging from 3.89 to 15.74 nM. Moreover, apoptosis studies were conducted on the most potent compound 8, to evaluate its proapoptotic potential. Interestingly, compound 8 induced the level of active caspase 3, and elevated the Bax/Bcl2 ratio 44 folds in comparison to the control. Finally, a molecular docking study was conducted to detect the probable interaction between the active compounds and the thymidylate synthase active site.

Synthesis of benzensulfonamides linked to quinazoline scaffolds as novel carbonic anhydrase inhibitors.

Carbonic anhydrase (CA) inhibitory activities of newly synthesized quinazoline-linked benzensulfonamides 10-29, 31, 32, 35, 36, and 45-51 against human CA (hCA) isoforms I, II, IX, and XII were measured and compared to that of acetazolamide (AAZ) as a standard inhibitor. Potent selective inhibitory activity against hCA I was exerted by compounds 14, 15, 17, 19, 20, 21, 24, 25, 28, 29, 31, 35, 45, 47, 49, and 51 with inhibition constant (KIs) values of 39.4-354.7 nM that were nearly equivalent or even greater than that of AAZ (KI, 250.0 nM). Compounds 15, 20, 24, 28, 29, 45 and 47 proved to have inhibitory activities against hCA II with (KIs, 0.73-16.5 nM) that were similar or improved to that of AAZ (KI, 12.0 nM). Compounds 13-29, 31-32, and 45-51 displayed potent hCA IX inhibitory activities (KIs, 1.6-32.2 nM) that were more effective than or nearly equal to AAZ (KI, 25.0 nM). Compounds 14, 15, 20, 21, 26, 45, and 47 exerted potent hCA XII inhibitory activities (KIs, 5.2-9.2 nM), indicating similar CAI activities as compared to that of AAZ (KI, 5.7 nM).

Synthesis, antitumor and antimicrobial activity of some new 6-methyl-3-phenyl-4(3H)-quinazolinone analogues: in silico studies.

Some new derivatives of substituted-4(3H)-quinazolinones were synthesized and evaluated for their in vitro antitumor and antimicrobial activities. The results of this study demonstrated that compound 5 yielded selective activities toward NSC Lung Cancer EKVX cell line, Colon Cancer HCT-15 cell line and Breast Cancer MDA-MB-231/ATCC cell line, while NSC Lung Cancer EKVX cell line and CNS Cancer SF-295 cell line were sensitive to compound 8. Additionally, compounds 12 and 13 showed moderate effectiveness toward numerous cell lines belonging to different tumor subpanels. On the other hand, the results of antimicrobial screening revealed that compounds 1, 9 and 14 are the most active against Staphylococcus aureus ATCC 29213 with minimum inhibitory concentration (MIC) of 16, 32 and 32 µg/mL respectively, while compound 14 possessed antimicrobial activities against all tested strains with the lowest MIC compared with other tested compounds. In silico study, ADME-Tox prediction and molecular docking methodology were used to study the antitumor activity and to identify the structural features required for antitumor activity.

Synthesis, antitumor activity and molecular docking study of some novel 3-benzyl-4(3H)quinazolinone analogues.

A novel series of 3-benzyl-substituted-4(3H)-quinazolinones were designed, synthesized and evaluated for their in vitro antitumor activity. The results of this study demonstrated that 2-(3-benzyl-6-methyl-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)acetamide, 2-(3-benzyl-6,7-dimethoxy-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)acetamide and 3-(3-benzyl-6-methyl-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)-propanamide have shown amazing broad spectrum antitumor activity with mean GI(50) (10.47, 7.24 and 14.12 µM. respectively), and are nearly 1.5-3.0-fold more potent compared with the positive control 5-FU with mean GI50, 22.60 µM. On the other hand, compounds 6 and 10 yielded selective activities toward CNS, renal and breast cancer cell lines, whereas compound 9 showed selective activities towards leukemia cell lines. Molecular docking methodology was performed for compounds 7 and 8 into ATP binding site of EGFR-TK which showed similar binding mode to erlotinib, while compound 11 into ATP binding site of B-RAF kinase inhibited the growth of melanoma cell lines through inhibition of B-RAF kinase, similar to PLX4032.

Synthesis and potential antitumor activity of 7-(4-substituted piperazin-1-yl)-4-oxoquinolines based on ciprofloxacin and norfloxacin scaffolds: in silico studies.

The potential antitumor activities of a series of 7-(4-substituted piperazin-1-yl)fluoroquinolone derivatives (1-14a,b) using ciprofloxacin and norfloxacin as scaffolds are described. These compounds exhibit potent and broad spectrum antitumor activities using 60 human cell lines in addition to the inherent antibacterial activity. Compounds 1a, 2a, 3b, 6b and 7a were found to be the most potent, while 2b, 5b, and 6a were found to have an average activity. The results of this study demonstrated that compounds 1a, 2a, 3b, 6b and 7a (mean GI50; 2.63-3.09 µM) are nearly 7-fold more potent compared with the positive control 5-fluorouracil (mean GI50; 22.60 µM). More interestingly, compounds 1a, 2a, 3b, 6b and 7a have an almost antitumor activity similar to gefitinib (mean GI50; 3.24 µM) and are nearly 2-fold more potent compared to erlotinib (mean GI50; 7.29 µM). In silico study and ADME-Tox prediction methodology were used to study the antitumor activity of the most active compounds and to identify the structural features required for antitumor activity.

Novel quinoxaline-3-propanamides as VGFR-2 inhibitors and apoptosis inducers.

Vascular endothelial growth factor receptor-2 is a vital target for therapeutic mediation in various types of cancer. This study was aimed at exploring the cytotoxic activity of seventeen novel quinoxaline-3-propanamides against colon cancer (HCT-116) and breast cancer (MCF-7) using MTT assay. Results revealed that compounds 8, 9, and 14 elicited higher cytotoxicity than the reference drugs, doxorubicin (DOX) and sorafenib. Interestingly, they are more selective for HCT-116 (SI 11.98-19.97) and MCF-7 (SI 12.44-23.87) compared to DOX (SI HCT-116 0.72 and MCF-7 0.9). These compounds effectively reduced vascular endothelial growth factor receptor-2; among them, compound 14 displayed similar VEGFR-2 inhibitory activity to sorafenib (IC50 0.076 M). The ability of 14 to inhibit angiogenesis was demonstrated by a reduction in VEGF-A level compared to control. Furthermore, it induced a significant increase in the percentage of cells at pre-G1 phase by almost 1.38 folds (which could be indicative of apoptosis) and an increase in G2/M by 3.59 folds compared to the control experiment. A flow cytometry assay revealed that compound 14 triggered apoptosis via the programmed cell death and necrotic pathways. Besides, it caused a remarkable increase in apoptotic markers, i.e., caspase-3 p53 and BAX. When compared to the control, significant increase in the expression levels of caspase-3 from 47.88 to 423.10 and p53 from 22.19 to 345.83 pg per ml in MCF-7 cells. As well, it increased the proapoptotic protein BAX by 4.3 times while lowering the antiapoptotic marker BCL2 by 0.45 fold. Docking studies further supported the mechanism, where compound 14 showed good binding to the essential amino acids in the active site of VEGFR-2. Pharmacokinetic properties showed the privilege of these hits over sunitinib: they are not substrates of P-gp protein; this suggests that they have less chance to efflux out of the cell, committing maximum effect; and in addition, they do not allow permeation to the BBB.

Synthesis and antitumor evaluation of trimethoxyanilides based on 4(3H)-quinazolinone scaffolds.

A novel series of 2-[(3-substituted-4(3H)-quinazolin-2-yl)thio]-N-(3,4,5-trimethoxyphenyl)acetamide (15-21) and 3-[(3-substituted-4(3H)-quinazolin-2-yl)thio])-N-(3,4,5-trimethoxyphenyl)propanamide (23-29) were designed, prepared and estimated for their anticancer activity in a solo dose 10 µM of the test compounds in the NCI 57 cell lines panel assay. Compounds 20, 23, 26, 27 and 28 revealed extensive-spectrum antitumor efficiency to numerous cell lines that belong to various tumor subpanels, while compounds 15, 16 and 19 possessed perceptive activity toward A498 and UO-31 renal cancer cell lines, and compound 17 showed selective effectiveness against NSC lung cancer NCI-H522 cell line. Additionally, compound 18 showed advanced activity against SR leukemia cell line, NSC lung cancer HOP-92 and renal cancer UO-31 cell lines.

Design, synthesis and biological evaluation of some novel substituted quinazolines as antitumor agents.

A novel series of 6-chloro-2-p-tolylquinazolinone and substituted-(4-methylbenzamido)benzamide (1-20) were designed, synthesized and evaluated for their in-vitro antitumor activity. Compounds 3, 14 and 16 possessed remarkable broad-spectrum antitumor activity. Compound 16 was found to be a particularly active growth inhibitor of the renal cancer (GI50 = 4.07 µM), CNS cancer (GI50 = 7.41 µM), ovarian cancer (GI50 = 7.41 µM) and non-small cell lung cancer (GI50 = 7.94 µM). Compound 16 ranks as nearly 1.5-fold more potent (mean GI50 = 15.8 µM) compared to 5-FU (mean GI50 = 22.6 µM).

Novel pirfenidone analogues: synthesis of pyridin-2-ones for the treatment of pulmonary fibrosis.

A new series of polysubstituted 1-aryl-2-oxo-1,2-dihydropyridine-3-carbonitriles and pyrazolo[3,4-b]pyridine-5-carbonitriles and pyrido[2,3-d]pyrimidine-6-carbonitriles have been synthesized and tested for their antifibrotic activity. Among the tested compounds, compounds IIc and IVb exhibited higher antifibrotic activity than the standard pirfenidone PD with a reduction of the hydroxyproline level to 50 and 140 micromol/lung, respectively. However, bicyclic pyridone VIIIb displayed a high mortality rate. Detailed syntheses, spectroscopic and biological data are reported.