Synthesis and biological evaluation of 1-benzyl-N-(2-(phenylamino)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxamides as antimitotic agents

A library of 1-benzyl-N-(2-(phenylamino)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxamides (7a–al) have been designed, synthesized and screened for their anti-proliferative activity against some selected human cancer cell lines namely DU-145, A-549, MCF-7 and HeLa. Most of them have shown promising cytotoxicity against lung cancer cell line (A549), amongst them 7f was found to be the most potent anti-proliferative congener. Furthermore, 7f exhibited comparable tubulin polymerization inhibition (IC₅₀ value 2.04 µM) to the standard E7010 (IC₅₀ value 2.15 µM). Moreover, flow cytometric analysis revealed that this compound induced apoptosis via cell cycle arrest at G₂/M phase in A549 cells. Induction of apoptosis was further observed by examining the mitochondrial membrane potential and was also confirmed by Hoechst staining as well as Annexin V-FITC assays. Furthermore, molecular docking studies indicated that compound 7f binds to the colchicine binding site of the β-tubulin. Thus, 7f exhibits anti-proliferative properties by inhibiting the tubulin polymerization through the binding at the colchicine active site and by induction of apoptosis.     

Synthesis,biological evaluation and molecular docking studies of aminochalcone derivatives as potential anticancer agents by targeting tubulin colchicine binding site

A series of aminochalcone derivatives have been synthesized, characterized by HRMS, ¹H NMR and ¹³C NMR and evaluated for their antiproliferative activity against HepG2 and HCT116 human cancer cell lines. The most of new synthesized compounds displayed moderate to potent antiproliferative activity against test cancer cell lines. Among the derivatives, compound 4 displayed potent inhibitory activity with IC₅₀ values ranged from 0.018 to 5.33 μM against all tested cancer cell lines including drug resistant HCT-8/T. Furthermore, this compound showed low cytotoxicity on normal human cell lines (LO2). The in vitro tubulin polymerization assay showed that compound 4 inhibited tubulin assembly in a concentration-dependent manner with IC₅₀ value of 7.1 μM, when compared to standard colchicine (IC₅₀ = 9.0 μM). Further biological evaluations revealed that compound 4 was able to arrest the cell cycle in G2/M phase. Molecular docking study demonstrated the interaction of compound 4 at the colchicine binding site of tubulin. All the results indicated that compound 4 is a promising inhibitor of tubulin polymerization for the treatment of cancer.     

Synthesis and biological evaluation of novel 4,7-dihydroxycoumarin derivatives as anticancer agents

A series of novel 4,7-dihydroxycoumarin based acryloylcyanohydrazone derivatives were synthesized and evaluated for antiproliferative activity against four different cancer cell lines (A549, HeLa, SKNSH, and MCF7). Most of the compounds displayed potent cytotoxicity with IC₅₀ values ranging from 3.42 to 31.28 µM against all the tested cancer cell lines. The most active compound, 8h was evaluated for pharmacological mechanistic studies on cell cycle progression and tubulin polymerization inhibition assay. The results revealed that the compound 8h induced the cell cycle arrest at G2/M phase and inhibited tubulin polymerization with IC₅₀ = 6.19 µM. Experimental data of the tubulin polymerization inhibition assay was validated by molecular docking technique and the results exhibited strong hydrogen bonding interactions with amino acids (ASN-101, TYR-224, ASN-228, LYS-254) of tubulin.     

Design,synthesis and biological evaluation of (E)-3-(3,4-dihydroxyphenyl)acrylylpiperazine derivatives as a new class of tubulin polymerization inhibitors

A series of novel (E)-3-(3,4-dihydroxyphenyl)acrylylpiperazine derivatives had been synthesized and evaluated their biological activities as potential tubulin polymerization inhibitors. Among these compounds, compound 3q exhibited potent antiproliferative activities against three cancer cell lines in vitro, and antitubulin polymerization activity with IC₅₀ of 0.92 μM, which was superior to that of colchicine (IC₅₀ = 1.34 μM). Docking simulation was performed to insert compound 3q into the crystal structure of tubulin at colchicine binding site to determine the probable binding model. These results suggested that compound 3q may be a promising antitubulin agent for the potential treatment of cancer.     

Sulfamic acid promoted one-pot synthesis of phenanthrene fused-dihydrodibenzo-quinolinones: Anticancer activity,tubulin polymerization inhibition and apoptosis inducing studies

A facile one-pot method for the synthesis of new phenanthrene fused-dihydrodibenzo-quinolinone derivatives has been successfully accomplished by employing sulfamic acid as catalyst. These new compounds were evaluated for their in vitro cytotoxic potential against human lung (A549), prostate (PC-3 and DU145), breast (MCF-7) and colon (HT-29 and HCT-116) cancer cell lines. Among all the tested compounds, one of the derivatives 8p showed good anti-proliferative activity against A549 lung cancer cell line with an IC₅₀ of 3.17?±?0.52?µM. Flow cytometric analyses revealed that compound 8p arrested both Sub G1 and G2/M phases of cell cycle in a dose dependent manner. The compound 8p also displayed significant inhibition of tubulin polymerization and disruption of microtubule network (IC₅₀ of 5.15?±?0.15?µM). Molecular docking studies revealed that compound 8p efficiently interacted with critical amino acid Cys241 of the α/β-tubulin by a hydrogen bond (SH…O?=?2.4?Å). Further, the effect of 8p on cell viability was also studied by AO/EB, DCFDA and DAPI staining. The apoptotic characteristic features revealed that 8p inhibited cell proliferation effectively through apoptosis by inducing the ROS generation. Analysis of mitochondrial membrane potential through JC-1 staining and annexin V binding assay indicated the extent of apoptosis in A549 cancer cells.     

Synthesis and evaluation of new 2-chloro-4-aminopyrimidine and 2,6-dimethyl-4-aminopyrimidine derivatives as tubulin polymerization inhibitors

Eighteen new 2-chloro-4-aminopyrimidine and 2,6-dimethyl-4-aminopyrimidine derivatives were synthesized and evaluated as tubulin polymerization inhibitor for the treatment of cancer. Among them, compounds 10, 17, 20 and 21 exhibited potent antiproliferative activities against five human cancer cell lines. Microtubule dynamics assay showed that compound 17 could effectively inhibit tubulin polymerization. Molecular docking studies were also carried out to understand the binding pattern. Further mechanism studies revealed that 17 could induce G2/M phase arrest, disrupt the organization of the cellular microtubule network and induce cell apoptosis and mitochondrial dysfunction.     

Design,synthesis and biological evaluation of a series of pyrano chalcone derivatives containing indole moiety as novel anti-tubulin agents

A new series of pyrano chalcone derivatives containing indole moiety (3–42, 49a–49r) were synthesized and evaluated for their antiproliferative activities. Among all the compounds, compound 49b with a propionyloxy group at the 4-position of the left phenyl ring and N-methyl-5-indoly on the right ring displayed the most potent cytotoxic activity against all tested cancer cell lines including multidrug resistant phenotype, which inhibits cancer cell growth with IC₅₀ values ranging from 0.22 to 1.80 μM. Furthermore, 49b significantly induced cell cycle arrest in G2/M phase and inhibited the polymerization of tubulin. Molecular docking analysis demonstrated the interaction of 49b at the colchicine binding site of tubulin. In experiments in vivo, 49b exerted potent anticancer activity in HepG2 human liver carcinoma in BALB/c nude mice. These results indicated these compounds are promising inhibitors of tubulin polymerization for the potential treatment of cancer.     

Synthesis,molecular properties prediction and biological evaluation of indole-vinyl sulfone derivatives as novel tubulin polymerization inhibitors targeting the colchicine binding site

Twenty-two novel indole-vinyl sulfone derivatives were designed, synthesized and evaluated as tubulin polymerization inhibitors. The physicochemical and drug-likeness properties of all target compounds were predicted by Osiris calculations. All compounds were evaluated for their antiproliferative activities, among them, compound 7f exhibited the most potent activity against a panel of cancer cell lines, which was 2–7 folds more potent than our previously reported compound 4. Especially, 7f displayed about 8-fold improvement of selective index as compared with compound 4, indicating that 7f might have lower toxicity. Besides, 7f inhibited the microtubule polymerization by binding to the colchicine site of tubulin. Further investigations showed that compound 7f effectively disrupted microtubule network, caused cell cycle arrest at G2/M phase and induced cell apoptosis in K562 cells. Moreover, 7f reduced the cell migration and disrupted capillary-like tube formation in HUVEC cells. Importantly, the in vivo anti-tumor activity of 7f was validated in H22 liver cancer xenograft mouse model without apparent toxicity, suggesting that 7f is a promising anti-tubulin agent for cancer therapy.     

Synthesis and antiproliferative evaluation of pyrazolo[1,5-a]-1,3,5-triazine myoseverin derivatives

Pyrazolo[1,5-a]-1,3,5-triazine myoseverin derivatives 1a–c were prepared from 4-(N-methyl-N-phenylamino)-2-methylsulfanylpyrazolo[1,5-a]-1,3,5-triazine 2. Their cytotoxic activity, inhibition of tubulin polymerization, and cell cycle effects were evaluated. Compounds 1a and 1c are potent tubulin inhibitors and displayed specific antiproliferative activity in colorectal cancer cell lines at micromolar concentrations.     

1,2,3-triazole tethered Indole-3-glyoxamide derivatives as multiple inhibitors of 5-LOX,COX-2 & tubulin: Their anti-proliferative & anti-inflammatory activity

To evaluate the role of COX-2 and 5-LOX as dual inhibitors in controlling the cancer cell proliferation, a set of two series having 42 compounds of 1, 2, 3-Tethered Indole-3-glyoxamide derivatives were synthesized by employing click chemistry approach and were also evaluated for their in vitro cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) inhibitory activities with in vivo anti-inflammatory and in vitro anti-proliferative potencies. Among the compounds tested, compounds 11q and 13s displayed excellent inhibition of COX-2 (IC₅₀ 0.12 µM) with good COX-2 selectivity index (COX-2/COX-1) of 0.058 and 0.046 respectively. Compounds 11q and 13s also demonstrated comparable 5-LOX inhibitory activity with IC₅₀ 7.73 and 7.43 µM respectively to that of standard Norhihydroguaiaretic acid (NDGA: IC₅₀ 7.31 µM). Among all the selected cell lines, prostate cancer cell line DU145 was found to be susceptible to this class of compounds. Among all the tested compounds, compounds 11g, 11i, 11k, 11q, 13r, 13s and 13u demonstrated excellent to moderate anti-proliferative activity with IC_50s ranging between 6.29 and 18.53 µM. Compounds 11q and 11g demonstrated better anti-proliferative activities against DU145 cancer cell line with IC₅₀ values 8.17 and 8.69 µM respectively when compared to the standard drug etoposide (VP16; IC₅₀ 9.80 µM). Compounds 11g, 11k, 11q, 13s and 13u showed good dual COX-2/5-LOX inhibitory potentials with excellent anti-proliferative activity. Results from carrageenan-induced hind paw edema demonstrated that compounds 11b, 11l, 11q and 13q exhibited significant anti-inflammatory activity with 69–77% inhibition at 3 h, 75–82% inhibition at 5 h when compared to the standard drug indomethacin (66.6% at 3 h and 77.94% at 5 h). Ulcerogenic study revealed that compounds 11q and 13q did not cause any gastric ulceration. In vitro tubulin assay resuted that compound 11q interfered with microtubulin dynamic and act as tubulin polymerization inhibitor. In silico molecular docking studies demonstrated that compounds 11q and 13s are occupying the colchicines binding site of tubulin polymer and 11q illustrated very good binding affinities towards COX-2 and 5-LOX.     

Design,synthesis and evaluation of novel indole derivatives as AKT inhibitors

Herein, we describe the discovery and synthesis of a new series of 1,2,4,7-tetra-substituted indole derivatives as novel AKT inhibitors by optimization of a weak hit methyl 4-(2-aminoethoxy)-1H-indole-2-carboxylate (1). Both representative compounds 6a and 6o exhibited the most potent inhibitory activities against AKT1, with inhibition rates of 72.5% and 78.6%, respectively, at concentrations of 10 nM. In addition, compounds 6a and 6o also potently inhibited the phosphorylation of the downstream GSK3 protein and displayed slightly better anti-proliferative activities in a prostate cancer cell line.     

Synthesis and biological evaluation of N-alkyl-N-(4-methoxyphenyl)pyridin-2-amines as a new class of tubulin polymerization inhibitors

Based on our prior antitumor hits, 32 novel N-alkyl-N-substituted phenylpyridin-2-amine derivatives were designed, synthesized and evaluated for cytotoxic activity against A549, KB, KB_VIN, and DU145 human tumor cell lines (HTCL). Subsequently, three new leads (6a, 7g, and 8c) with submicromolar GI₅₀ values of 0.19–0.41 μM in the cellular assays were discovered, and these compounds also significantly inhibited tubulin assembly (IC₅₀ 1.4–1.7 μM) and competitively inhibited colchicine binding to tubulin with effects similar to those of the clinical candidate CA-4 in the same assays. These promising results indicate that these tertiary diarylamine derivatives represent a novel class of tubulin polymerization inhibitors targeting the colchicine binding site and showing significant anti-proliferative activity.     

Anti-tumor activity evaluation of novel tubulin and HDAC dual-targeting inhibitors

Histone deacetylases (HDACs) have proven to be promising targets for the development of anti-cancer drugs. In this study, we reported a series of novel chalcone based tubulin and HDAC dual-targeting inhibitors. Three compounds inhibited the activities of HDAC and tubulin polymerization simultaneously and displayed anti-proliferative activities toward eleven human tumor cell lines. Compound 8a remarkably induced growth inhibition, apoptosis and G2/M phase arrest of A549 tumor cells. Finally, the inhibitory activities of 8a against HDAC6 and tubulin were rationalized by molecular docking studies.     

Anti-cancer activity of m-carborane-containing trimethoxyphenyl derivatives through tubulin polymerization inhibition

m-Carborane-containing compound 1a was identified as a cell growth inhibitor from a random screening of a boron compound library. As 1a is a mixture of diastereomers due to the presence of two chiral carbons, we designed achiral derivatives 2–4 and studied the structure-activity relationships of the methoxy groups on the benzene ring. 3,4,5-Trimethoxybenzyl derivative 2a and 3,4,5-trimethoxybenzoyl derivative 3a showed more potent anti-cancer activity against the human breast cancer cell line MDA-MB-453 than lead compound 1a. Compound 3a inhibited tubulin polymerization in a dose-dependent manner.     

Synthesis and anticancer activity of analogues of phenstatin,with a phenothiazine A-ring,as a new class of microtubule-targeting agents

A new family of microtubule-targeting agents with a phenothiazine A-ring was synthesized and evaluated for anti-proliferative activity and interaction with tubulin. These new derivatives showed significant activities against cellular proliferation and tubulin polymerization, rather similar to those of phenstatin. Phenothiazine derivative 21 proved to be the most potent compound synthesized with GI₅₀ values ranging from 29 to 93 nM on different cell lines. The same compound showed a better inhibition of COLO 205, A498, and MCF7 cell lines than the parent phenstatin.     

Antimitotic activity of lobaric acid and a new benzofuran,sakisacaulon A from Stereocaulon sasakii

Lobaric acid (1) has been isolated from lichen, Stereocaulon sasakii together with a new benzofuran, sakisacaulon A (2). Lobaric acid (1) inhibited the polymerization of tubulin. Structure–activity relationship of lobaric acid and its derivatives on inhibitory activity of tubulin polymerization was discussed.     

Synthesis and biological evaluation of a series of podophyllotoxins derivatives as a class of potent antitubulin agents

A series of eight novel podophyllotoxin derivatives were designed, synthesized and evaluated for biological activities. The antiproliferative activities were tested against a panel of human cancer cell lines (K562, SGC, Hela and HepG) and the inhibition of tubulin polymerization was also evaluated. Compound 8e displayed significant antiproliferative activities for all four cell lines and strong levels of tubulin polymerization inhibition effect. Combined with cell apoptosis and cell cycle analysis, it demonstrated that compound 3e that effectively interfere with tubulin dynamics prevent mitosis in cancer cells, leading to cell cycle arrest and, eventually dose dependent apoptosis. All experimental measurements were also supported by molecular docking simulations of colchicine binding site, which revealed the governing forces for the binding behavior and a good relationship with anti-tubulin activity and antiproliferative activities. The synthesis and biological studies provided an interesting new class of antitubulin agents for development of lead compounds and also a direction for further structure modification to obtain more potent anti-cancer drugs.     

Synthesis and biological evaluation of 7-methoxy-1-(3,4,5-trimethoxyphenyl)-4,5-dihydro-2H-benzo[e]indazoles as new colchicine site inhibitors

The colchicine site inhibitors (CSIs) displayed both antimitotic and vascular disrupting activities, therefore are promising potential antitumor agents. In this study, a series 1-phenyl-4,5-dihydro-2H-benzo[e]indazoles were found as new CSIs of which the bioactive configuration was locked. Among them, compounds C1 and C2 displayed the best activity, with tubulin polymerization IC₅₀ of 3.4 and 1.5 μM, and growth IC50 of low nanomolar concentrations against human colon cancer cell lines. In addition, compound C1 showed excellent broad-spectrum antitumor activity in the NCI-60 Human Tumor Cell Lines Screen, encouraging further study of this antitumor compound.     

Design,synthesis and biological evaluation of novel β-pinene-based thiazole derivatives as potential anticancer agents via mitochondrial-mediated apoptosis pathway

A series of novel β-pinene-based thiazole derivatives were synthesized and characterized by HRMS, ¹H NMR, and ¹³C NMR analyses as potential antineoplastic agents. Derivatives were evaluated for their anticancer activities in vitro, and the data manifested that most target compounds showed potent anti-proliferative activities against three human cancer cell lines. Especially, compound 5g displayed excellent cytotoxic activity against Hela, CT-26, and SMMC-7721 cell lines with IC₅₀ values of 3.48 ± 0.14, 8.84 ± 0.16, and 6.69 ± 0.15 µM, respectively. To determine the underlying mechanism of compound 5g on cell viability, DAPI staining, Annexin-V/PI staining, JC-1 staining, DCFDA staining, and Western blot analysis were performed. Our data showed that compound 5g inhibited cell proliferation by inducing apoptosis and cell cycle arrest of Hela cells at the G0/G1 phase in a dose dependent manner. Further studies revealed that compound 5g enhanced levels of reactive oxygen species (ROS), caused a decrease in mitochondrial membrane potential, increased the release of mitochondrial cytochrome C, and affected the expression of Bax, Bcl-2, caspase-3 and caspase-9. Thus, our findings indicated that compound 5g induced apoptosis in Hela through ROS-mediated mitochondrial dysfunction signaling pathways.