Combretastatin A-4 inspired novel 2-aryl-3-arylamino-imidazo-pyridines/pyrazines as tubulin polymerization inhibitors, antimitotic and anticancer agents (original) (raw)
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SynOpen, 2023
The development of new pharmacologically active molecules targeting tubulin polymerization has recently attracted great interest in research groups. In efforts to develop new potent anticancer compounds, imidazole-tethered/fused pharmacologically active aryl derivatives possessing different substitution patterns targeting tubulin polymerization have been rationally designed and synthesized. The target molecules (P1-5 and KG1-5) were synthesized by multistep syntheses involving the reaction of intermediate 2-aminophenyl-tethered imidazoles with appropriate reactants in the presence of p-TsOH under different conditions. The synthesized compounds displayed moderate to good cytotoxicity, comparable to that of colchicine, against four cancer cell lines (MCF-7, MD-MBA-231, A549, and HCT-116). Compounds P2 and P5, with an imidazoloquinoxaline moiety, emerged as potential leads with cytotoxicity profiles against these cell lines similar to colchicine. Compounds P2 and P5 arrested cell division at the G2/M phase and prevented cancerous cell growth through induced apoptosis. These results favored the hypothesis that the compounds might act by binding to the colchicine binding site, which was further confirmed with the help of a tubulin polymerization inhibition assay. The results encourage the further exploration of imidazoloquinoxalines as promising leads that deserve advanced clinical investigation.
Synthesis and Evaluation of Azetidinone Analogues of Combretastatin A-4 as Tubulin Targeting Agents
Journal of Medicinal Chemistry, 2010
The synthesis and antiproliferative activity of a new series of rigid analogues of combretastatin A-4 are described which contain the 1,4-diaryl-2-azetidinone (β-lactam) ring system in place of the usual ethylene bridge present in the natural combretastatin stilbene products. These novel compounds are also substituted at position 3 of the β-lactam ring with an aryl ring. A number of analogues showed potent nanomolar activity in human MCF-7 and MDA-MB-231 breast cancer cell lines, displayed in vitro inhibition of tubulin polymerization and did not cause significant cytotoxicity in normal murine breast epithelial cells. 4-(4-Methoxyaryl)-substituted compound 32, 4-(3-hydroxy-4-methoxyaryl)-substituted compounds 35 and 41 and the 3-(4-aminoaryl)-substituted compounds 46 and 47 displayed the most potent anti-proliferative activity of the series. β-Lactam 41 in particular showed sub-nanomolar activity in MCF-7 breast cancer cells (IC50 = 0.8nM) together with significant in vitro inhibition of tubulin polymerization and has been selected for further biochemical assessment. These novel β-lactam compounds are identified as potentially useful scaffolds for the further development of antitumour agents which target tubulin.
Archiv der Pharmazie, 2012
A series of novel 1-(3 0 ,4 0 ,5 0 -trimethoxybenzoyl)-3,5-diarylpyrazoline derivatives were synthesized and evaluated for their cytotoxic properties on different cancer cell lines and tubulin polymerization inhibitory activity. Compounds 6d and 6e exhibited remarkable cytotoxic activity against different cancer cell lines with good tubulin polymerization inhibitory activity. Compound 6d exhibited moderate selectivity toward renal cancer and breast cancer subpanels with selectivity ratios of 3.06 and 5.11, respectively, at the cytostatic activity (TGI) level. Compounds 6e and 6d achieved good tubulin polymerization inhibitory activity with IC 50 values of 17 and 40 mM, respectively. The photomicrographs made for compounds 6d and 6e on cellular microtubules indicated that the cytotoxicity of these compounds can be attributed to their ability to interfere with microtubule assembly. Molecular modeling studies involving compound 6e with the colchicine binding site of a,b-tubulin revealed hydrogen-bonding and hydrophobic interactions with several amino acids in the colchicine binding site of b-tubulin. R 1 = H, IIIa R 1 = OH, IIIb Chart 1. Different inhibitors for tubulin polymerization. 536 M. Abdel-Aziz et al.
Biological & Pharmaceutical Bulletin, 2016
A series of pyrazoline derivatives 2a-e, 3a-e and 4a-e structurally related to combretastatin A4 (CA-4) were synthesized and characterized by spectroscopic means and elemental analyses. In these compounds, the cis double bond of CA-4 was replaced with the pyrazoline ring aiming to enhance the cytotoxic effects displayed by CA-4 and to prevent the cis/trans isomerization that is associated with inactivation of CA-4. The cytotoxic activity of all new compounds was investigated in vitro against MCF-7 and HCT-116 cell lines. The inhibition of tubulin polymerization by the most active compounds 3d, 4a and e was evaluated. The cytotoxicity of 4e was correlated with induction of apoptosis and caspase-3 activation in vitro thus indicating the apoptotic pathway of anticancer effect of these compounds. Furthermore, in vivo evaluation of the synthesized compounds was carried out against Ehrlich's ascites carcinoma (EAC) solid tumor grown in mice. Compounds 2c, 3a and e showed significant reduction in tumor weight, and about 2-4 fold increase in caspase-3 expression.
A new class of pyrazole and isoxazole conjugates were synthesized and evaluated for their cytotoxic activity against various human cancer cell lines. These compounds have shown significant cytotoxicity with lower IC50 values. FACS results revealed that A549 cells treated with these compounds arrested cells at the G2/M phase of the cell cycle apart from activating cyclin B1 protein levels. Particularly, compounds 9a and 9b demonstrated a remarkable inhibitory effect on tubulin polymerization and showed a pronounced inhibitory effect on tubulin polymerization with IC50 values of 1.28 µM and 0.28 µM respectively, whereas nocodazole, a positive control, has shown lower antitubulin activity with an IC50 value of 2.64 µM. Furthermore, these compounds induced apoptosis by loss of mitochondrial membrane potential, propidium iodide (PI) staining and the activation of caspase-3. Results of a fluorescence based competitive colchicine binding assay suggest that these conjugates bind successfully at the colchicine binding site of tubulin. These investigations reveal that such conjugates containing pyrazole with a trimethoxy phenyl ring and indole moieties have potential for the development of newer chemotherapeutic agents.
Bioorganic chemistry, 2018
A novel quinolinyl pyrrolone and quinolinyl pyridazinone derivatives has been synthesized and characterized using different spectroscopic and elemental analysis techniques. Most of the target compounds displayed promising antiproliferative activity; In general, the pyrrolone derivatives 4a-f exhibited higher antiproliferative activity than their corresponding pyridazinone. The pyrrolone 4f showed outstanding antiproliferative activity with moderate selectivity against CNS and renal cancer with selectivity ratio of 3.49 and 3.56, respectively. Compound 4e and 5d experienced tubulin polymerization inhibitory activity comparable to that of vincristine while 4c, 4e and 4d showed good BRAF kinase inhibition compared to Erlotinib. Docking of compound 4e into colchicine binding site and biological assay results revealed that these compounds act mainly through tubulin polymerization inhibitory mechanism and can exhibit pre G1 apoptosis and cell cycle arrest at G2/M phase.
Biological & Pharmaceutical Bulletin, 2016
A series of pyrazoline derivatives 2a-e, 3a-e and 4a-e structurally related to combretastatin A4 (CA-4) were synthesized and characterized by spectroscopic means and elemental analyses. In these compounds, the cis double bond of CA-4 was replaced with the pyrazoline ring aiming to enhance the cytotoxic effects displayed by CA-4 and to prevent the cis/trans isomerization that is associated with inactivation of CA-4. The cytotoxic activity of all new compounds was investigated in vitro against MCF-7 and HCT-116 cell lines. The inhibition of tubulin polymerization by the most active compounds 3d, 4a and e was evaluated. The cytotoxicity of 4e was correlated with induction of apoptosis and caspase-3 activation in vitro thus indicating the apoptotic pathway of anticancer effect of these compounds. Furthermore, in vivo evaluation of the synthesized compounds was carried out against Ehrlich's ascites carcinoma (EAC) solid tumor grown in mice. Compounds 2c, 3a and e showed significant reduction in tumor weight, and about 2-4 fold increase in caspase-3 expression.