Design,synthesis and biological research of novel N-phenylbenzamide-4-methylamine acridine derivatives as potential topoisomerase I/II and apoptosis-inducing agents

A series of novel N-phenylbenzamide-4-methylamine acridine derivatives were designed and synthesized based initially on the structure of amsacrine (m-AMSA). Molecular docking suggested that the representative compound 9a had affinity for binding DNA topoisomerase (Topo) II, which was comparable with that of m-AMSA, and furthermore that 9a could have preferential interactions with Topo I. After synthesis of 9a and analogues 9b-9f, these were all tested in vitro and the synthesized compounds displayed potent antiproliferative activity against three different cancer cell lines (K562, CCRF-CEM and U937). Among them, compounds 9b, 9c and 9d exhibiting the highest activity with IC₅₀ value ranging from 0.82 to 0.91 μM against CCRF-CEM cells. In addition, 9b and 9d also showed high antiproliferative activity against U937 cells, with IC₅₀ values of 0.33 and 0.23 μM, respectively. The pharmacological mechanistic studies of these compounds were evaluated by Topo I/II inhibition, western blot assay and cell apoptosis detection. In summary, 9b effectively inhibited the activity of Topo I/II and induced DNA damage in CCRF-CEM cells and, moreover, significantly induced cell apoptosis in a concentration-dependent manner. These observations provide new information and guidance for the structural optimization of more novel acridine derivatives.     

Design,synthesis and anticancer evaluation of acridine hydroxamic acid derivatives as dual Topo and HDAC inhibitors

Multitarget inhibitors design has generated great interest in cancer treatment. Based on the synergistic effects of topoisomerase and histone deacetylase inhibitors, we designed and synthesized a new series of acridine hydroxamic acid derivatives as potential novel dual Topo and HDAC inhibitors. MTT assays indicated that all the hybrid compounds displayed good antiproliferative activities with IC₅₀ values in low micromolar range, among which compound 8c displayed potent activity against U937 (IC₅₀?=?0.90?μM). In addition, compound 8c also displayed the best HDAC inhibitory activity, which was several times more potent than HDAC inhibitor SAHA. Subsequent studies indicated that all the compounds displayed Topo II inhibition activity at 50?μM. Moreover, compound 8c could interact with DNA and induce U937 apoptosis. This study provides a suite of compounds for further exploration of dual Topo and HDAC inhibitors, and compound 8c can be a new dual Topo and HDAC inhibitory anticancer agent.     

Design,synthesis and biological evaluation of novel 1,3,4-trisubstituted pyrazole derivatives as potential chemotherapeutic agents for hepatocellular carcinoma

A series of novel 1,3,4-trisubstituted pyrazole derivatives were synthesized and evaluated for their cytotoxic activity against three different cancer cell lines namely HCT116, UO-31 and HepG2. Compounds 3b, 3d, 7b and 9 showed excellent anticancer activity against all the tested cancer cell lines and had better cytotoxic activities than the reference drug, Sorafenib. Therefore, these compounds were chosen to be further evaluated in a panel of HCC cell lines. Among them, 3b and 7b were the most active compounds against HCC cells used here. Further studies on the mechanism demonstrated that 3b and 7b induced apoptosis in addition to induction of cell cycle arrest at G2/M phase in HepG2 and Huh7 cells. Consistent with these results, caspase-3 assay was done and the results revealed that the pro-apoptotic activity of the target compounds could be due to the stimulation of caspases-3. In addition, CDK1 inhibition assay was done and it was found that compounds 3b and 7b inhibited CDK1 activities with IC₅₀ values of 2.38 and 1.52 µM, respectively. Finally, pyrazole derivatives 3b and 7b showed potent bioactivities, indicating that these compounds could be potent anticancer drugs in the future.     

Design,synthesis and biological evaluation of new carbazole derivatives as anti-cancer and anti-migratory agents

Based on the efficacy of EHop-016 as an inhibitor of migration and Rac1 activation, a new series of carbazole derivatives has been synthesized. Cytotoxic and anti-migratory effects of these compounds were evaluated in MCF-7 and MDA-MB-231 breast cancer cell lines. Preliminary investigations of their anticancer activity demonstrated that several compounds have moderate antiproliferative effects on cancer cell lines with GI₅₀ values in the range of 13–50?µM. Furthermore, compounds 3b and 11b inhibit migration activity of metastatic cell line MDA-MB-231 by 32% and 34%, respectively. Compound 11b was shown to inhibit activation of the Rho GTPase Rac1 by 55% at 250?nM in both MDA-MB-231 and MDA-MB-435 cell lines. Compared with the IC₅₀ of Rac1 inhibition by lead compound EHop-016 of 1.1?µM, compound 11b demonstrates 4X improved in vitro efficacy.     

Design,synthesis and biological evaluation of novel perimidine o-quinone derivatives as non-intercalative topoisomerase II catalytic inhibitors

For the development of novel anticancer agents, we designed and synthesized a total of 37 perimidine o-quinone derivatives containing the o-quinone group at the A or B ring and different substituents (alkyl groups, aryl groups or heterocycles) at the C ring of the compounds. The structure-activity relationships (SARs) were established based on the cytotoxicity data of compounds from the HL-60, Huh7, Hct116, and Hela cell lines. The cytotoxicity results showed that most compounds exhibited potent cytotoxicity. In particular, compound b-12 showed the best anti-proliferative activity (IC₅₀ ≤ 1 μM) against four cancer cell lines and strong potency against the HL-60/MX2 (0.47 μM) cell line, which is resistant to Topo II poisons. Further studies showed that b-12 exhibited potent Topo IIα inhibitory activity (IC₅₀ = 7.54 μM) compared with Topo I, which acted as a class of non-intercalative Topo IIα catalytic inhibitor by inhibiting the ATP binding site of Topo II. Cell apoptosis and cell cycle assays confirmed that b-12 could induce the apoptosis of Huh7 cells in a dose-dependent manner.     

Synthesis,anticancer, structural,and computational docking studies of 3-benzylchroman-4-one derivatives

A series of 3-Benzylchroman-4-ones were synthesized and screened for anticancer activity by MTT assay. The compounds were evaluated against two cancerous cell lines BT549 (human breast carcinoma), HeLa (human cervical carcinoma), and one noncancerous cell line vero (normal kidney epithelial cells). 3b was found to be the most active molecule against BT549 cells (IC₅₀?=?20.1?µM) and 3h against HeLa cells (IC₅₀?=?20.45?µM). 3b also exhibited moderate activity against HeLa cells (IC₅₀?=?42.8?µM). The molecular structures of 3h and 3i were solved by single crystal X-ray crystallographic technique. Additionally, the molecular docking studies between the tumour suppressor protein p53 with the lead compound 3h, which exhibited better anticancer activity against HeLa cells was examined.     

Synthesis and biological evaluation of coumarin-1,3,4-oxadiazole hybrids as selective carbonic anhydrase IX and XII inhibitors

With an aim to develop novel heterocyclic hybrids as potent anticancer agents, we synthesized a series of coumarin-1,3,4-oxadiazole hybrids (7a-t) and evaluated for their inhibitory activity against the four physiologically relevant human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms CA I, CA II, CA IX and CA XII. The CA inhibition results clearly indicated that the coumarin-1,3,4-oxadiazole derivatives (7a-t) exhibited selective inhibition of the tumor associated isoforms, CA IX and CA XII over CA I and II isoforms. Among all, compound 7b, exhibited significant inhibition in lower micromolar potency against hCA XII, with a K_i of 0.16 µM and compound 7n, exhibited significant inhibition in lower micromolar potency against hCA IX, with a K_i of 2.34 µM respectively. Therefore, compound 7b and 7n could be the potential leads for development of selective anticancer agents by exhibiting a novel mechanism of action through hCA IX and XII inhibition.     

Synthesis,biological evaluation and molecular docking of novel pyrazole derivatives as potent carbonic anhydrase and acetylcholinesterase inhibitors

A series of substituted pyrazole compounds (1–8 and 9a, b) were synthesized and their structure was characterized by IR, NMR, and Mass analysis. These obtained novel pyrazole derivatives (1–8 and 9a, b) were emerged as effective inhibitors of the cytosolic carbonic anhydrase I and II isoforms (hCA I and II) and acetylcholinesterase (AChE) enzymes with K_i values in the range of 1.03 ± 0.23–22.65 ± 5.36 µM for hCA I, 1.82 ± 0.30–27.94 ± 4.74 µM for hCA II, and 48.94 ± 9.63–116.05 ± 14.95 µM for AChE, respectively. Docking studies were performed for the most active compounds, 2 and 5, and binding mode between the compounds and the receptors were determined.     

A novel tetrazole analogue of resveratrol is a potent anticancer agent

A series of novel tetrazole analogues of resveratrol were synthesized and evaluated for their anti-leukemic activity against an extensive panel of human cancer cell lines and against the MV4-11 AML cell line. These molecules were designed as drug-like derivatives of the resveratrol analogue DMU-212 and its cyano derivatives. Four compounds 8g, 8h, 10a and 10b exhibited LD₅₀ values of 4.60?µM, 0.02?µM, 1.46?µM, and 1.08?µM, respectively, against MV4-11 leukemia cells. The most potent compounds, 8h and 10b, were also found to be active against an extensive panel of human hematological and solid tumor cell lines; compound 8h was the most potent compound with GI₅₀ values <10?nM against more than 90% of the human cancer cell lines in the 60-cell panel. Analogues 8g, 8h, 10a and 10b were also tested for their ability to inhibit the polymerization of tubulin, and compound 8h was found to be the most potent analogue. Molecular modeling studies demonstrated that 8h binds to the colchicine binding site on tubulin. Thus, compound 8h is considered to be a lead druglike molecule from this tetrazole series of compounds.     

Cytotoxicity mechanisms of pyrazino[1,2-b]isoquinoline-4-ones and SAR studies

The cytotoxicity showed by 1b, an interesting representant of the title compounds, for HT-29 human colon cancer cells (CI₅₀ value of 1.95 × 10^?7 M) has been related to the induced cell death at the G2 phase and not to DNA damage. This compound promotes the degradation of components of the G2/M checkpoint machinery, in particular cdc2, Cyclin B1 and Wee1, which represents a novel mechanism of cytotoxicity. Degradation of Wee1 seems to be mediated by proteasome activity but degradation of cdc2 has to occur through a different mechanism. The activity of 1b on G2 cell cycle components suggests that tumor cells that are arrested in G2/M by anticancer drugs like cisplatin could be targeted by compound 1b, increasing the apoptosis induction, and that their optimized analogs might be useful in the treatment of colon cancer through combination therapies with cisplatin or other anticancer drugs that affect the cytoskeleton integrity such as taxol and taxotere.SAR studies with compounds obtained by manipulation of the N(2) and C(4)-functional groups and the C(6)-chain of compound 1b have confirmed the importance of these structural features in the in vitro antitumor activity. Fused oxazolidine derivatives as compound 5 were inactive, and the lack of activity found in the replacement of the C(4)-lactam by a cyanoamine function, as in compounds 8–10, could be explained considering that their all-syn relative configuration makes them too stable to generate alkylating iminium species.     

Synthesis and biological evaluation of histone deacetylase and DNA topoisomerase II-Targeted inhibitors

HDAC inhibitors enable histones to maintain a high degree of acetylation. The resulting looser state of chromatin DNA may increase the accessibility of DNA drug targets and consequently improve the efficiency of anticancer drugs targeting DNA, such as Topo II inhibitors. A novel class of nucleoside-SAHA derivatives has been designed and synthesized based on the synergistic antitumor effects of topoisomerase II and histone deacetylase inhibitors. Their inhibitory activities toward histone deacetylases and Topo II, and their cytotoxicities in cancer cell lines, were evaluated. Among the synthesized hybrid compounds, compound 16b showed the potent HDAC inhibitory activity at a low nanomolar level and exhibited antiproliferative activity toward cancer cell lines including MCF-7 (breast), HCT-116 (colon), and DU-145 (prostate) cancer cells at a low micromolar level. Moreover, compound 16a showed HDAC6-selectivity 20-fold over HDAC1.     

Novel thymol bearing oxypropanolamine derivatives as potent some metabolic enzyme inhibitors – Their antidiabetic,anticholinergic and antibacterial potentials

A series of classical and newly synthesized thymol bearing oxypropanolamine compounds were synthesized and characterized. Their in vitro antibacterial activity on A. baumannii, P. aeruginosa, E. coli and S. aureus strains were investigated with agar well diffusion method. The results were compared with commercially available drug active compounds. As well as 3a, 3b and 3c have the most significant antibacterial effect among all the tested compounds; approximately all of them have more antibacterial activity than the reference drugs. These novel thymol bearing oxypropanolamine derivatives were effective inhibitors of the α-glycosidase, cytosolic carbonic anhydrase I and II isoforms (hCA I and II), and acetylcholinesterase enzymes (AChE) with K_i values in the range of 463.85–851.05 µM for α-glycosidase, 1.11–17.34 µM for hCA I, 2.97–17.83 µM for hCA II, and 13.58–31.45 µM for AChE, respectively.     

Design,synthesis, in silico and in vitro evaluation of thiophene derivatives: A potent tyrosine phosphatase 1B inhibitor and anticancer activity

A series of novel methyl 4-(4-amidoaryl)-3-methoxythiophene-2-carboxylate derivatives were designed against the active site of protein tyrosine phosphatise 1B (PTP1B) enzyme using MOE.2008.10. These molecules are also subjected for in silico toxicity prediction studies and considering their corresponding drug scores, it implied that, the molecules are promising as anticancer agents. The designed compounds were synthesized by using suitable methods and characterized. They were subjected to inhibitory activity against PTP1B and in vitro anticancer activity by MTT assay. Most of the tested compounds showed potent inhibitory activity against PTP1B, among the compounds tested, compound 5b exhibited the highest activity (IC₅₀ = 5.25 µM) and remarkable cytotoxic activity at 0.09 µM of IC₅₀ against the MCF-7 cell line. In addition to this, compound 5c also showed potential anticancer activity at 2.22 µM of IC₅₀ against MCF-7 and 0.72 µM against HepG2 cell lines as well as PTP1B inhibitory activity at IC₅₀ of 6.37 µM.     

Synthesis and in vitro anticancer evaluation of some fused indazoles,quinazolines and quinolines as potential EGFR inhibitors

derivatives of benzo[g]indazole 5a, b, benzo[h]quinazoline 7, 12a-c, 13a-c and 15a-c and benzo[h]quinoline 17a-c and 19a-c were synthesized from 6-methoxy-3,4-dihydronaphthalen-1(2H)-one (1). Anticancer activity of all the synthesized compounds was evaluated against four cancerous cell lines; HepG2, MCF-7, HCT116 and Caco-2. MCF-7 cells emerged as the most sensitive cell line against the target compounds. All the examined compounds, except 5a and 5b, displayed potent to moderate anticancer activity against MCF-7 cells with an IC₅₀ values ranging from 7.21 to 21.55 µM. In particular, compounds 15c and 19b emerged as the most potent derivatives against EGFR-expressing MCF-7 cells with IC₅₀ values = 7.70 ± 0.39 and 7.21 ± 0.43 μM, respectively. Additionally, both compounds did not display any significant cytotoxicity towards normal BHK-21 fibroblast cells (IC₅₀ value > 200 µM), thereby providing a good safety profile as anticancer agents. Furthermore, compounds 15c and 19b displayed potent inhibitory activity towards EGFR in the sub-micromolar range (IC₅₀ = 0.13 ± 0.01 and 0.14 ± 0.01 μM, respectively), compared to that of Erlotinib (IC₅₀ = 0.11 ± 0.01 μM). Docking studies for 15c and 19b into EGFR active site was carried out to explore their potential binding modes. Therefore, compounds 15c and 19b can be considered as interesting candidates for further development of more potent anticancer agents.     

Synthesis of 2-,4,-6-, and/or 7-substituted quinoline derivatives as human dihydroorotate dehydrogenase (hDHODH) inhibitors and anticancer agents: 3D QSAR-assisted design

Following our research for human dihydroorotate dehydrogenase (hDHODH) inhibitors as anticancer agents, herein we describe 3D QSAR-based design, synthesis and in vitro screening of 2-,4,-6-, and/or 7-substituted quinoline derivatives as hDHODH inhibitors and anticancer agents. We have designed 2-,4,-6-, and/or 7-substituted quinoline derivatives and predicted their hDHODH inhibitory activity based on 3D QSAR study on 45 substituted quinoline derivatives as hDHODH inhibitors, and also predicted toxicity. Designed compounds were docked into the binding site of hDHODH. Designed compounds which showed good predictive activity, no toxicity, and good docking score were selected for the synthesis, and in vitro screening as hDHODH inhibitors in an enzyme inhibition assay, and anticancer agents in MTT assay against cancer cell lines (HT-29 and MDA-MB-231). Synthesized compounds 7 and 14 demonstrated IC₅₀ value of 1.56?µM and 1.22?µM, against hDHODH, respectively, and these are our lead compounds for the development of new hDHODH inhibitors and anticancer agents.     

Design and synthesis of novel imidazo[4,5-b]pyridine based compounds as potent anticancer agents with CDK9 inhibitory activity

New imidazo[4,5-b]pyridine derivatives were designed, synthesized and screened for their anticancer activity against breast (MCF-7) and colon (HCT116) cancer cell lines. Nine compounds (I, II, IIIa, IIIb, IV, VI, VIIa, VIII, IX) showed significant activity against MCF-7, while six compounds (I, VIIc, VIIe, VIIf, VIII, IX) elicited a remarkable activity against HCT116. Compounds showing significant anticancer activity revealed remarkable CDK9 inhibitory potential (IC₅₀ = 0.63–1.32 μM) relative to sorafenib (IC₅₀ = 0.76 μM). Moreover, a molecular docking study was performed to illustrate the binding mode of the most active compounds in the active site of CDK9 where it revealed superior binding affinity relative to the natural ligand (T3C).     

Novel thioureido-benzenesulfonamide derivatives with enaminone linker as potent anticancer,radiosensitizers and VEGFR2 inhibitors

In this study, novel series of thioureido-benzenesulfonamide derivatives bearing an enaminone linker either meta or para oriented and having terminal linear or substituted aromatic or heteroaromatic ring system 5–16a,b were designed and synthesized based on the general pharmacophoric features of type II VEGFR2 inhibitors. Evaluation of the synthesized compounds against HEPG2 hepatocellular carcinoma cells in vitro identified compounds 5b, 6b and 10–13b as most active anticancer agents with IC₅₀ equal to 0.12, 0.29, 0.58, 0.44, 0.42 and 0.66?µM, respectively. These compounds were evaluated for their ability to in vitro inhibit VEGFR2 kinase enzyme. The results demonstrated highly potent dose-related VEGFR2 inhibition with IC₅₀ values in nanomolar range (33, 57, 210, 37, 37 and 220?nM, respectively). The radiosensitizing ability of the most promising compounds was studied which showed an increase in the cell killing effect of radiation after combination with the synthesized compounds which revealed lowered IC₅₀ by nearly 50%. Molecular docking for the most potent compounds was performed to predict their possible binding mode within VEGFR2 active site and they showed binding affinity in a similar way to sorafenib.     

Investigation of chemical reactivity of 2-alkoxy-1,4-naphthoquinones and their anticancer activity

To establish the structure-activity relationship of 5-hydroxy-1,4-naphthoquinones toward anticancer activity, a series of its derivatives were prepared and tested for the activity (IC₅₀ in µM) against three cell lines; colo205 (colon adenocarcinoma), T47D (breast ductal carcinoma) and K562 (chronic myelogenous leukemia). Among them 2 (IC₅₀: 2.3; 2.0; 1.4?µM), 6 (IC₅₀: 1.9; 2.2; 1.3?µM), 9 (IC₅₀: 0.7; 1.7; 0.9?µM) and 10 (IC₅₀:1.7; 1.0; 1.2?µM) showed moderate to excellent activity. Our perception toward the DNA substitution of alkoxy groups at the C2 position of these naphthoquinones for the anticancer activity led us to investigate their reactivity of substitution toward dimethylamine as a nucleophile. The ease of the substitution of alkoxy groups at the C2 position with dimethylamine is strongly accelerated by hydroxyl group at C5 position and is well correlated with the found anticancer activity results.     

Design,synthesis, molecular docking and biological activity evaluation of some novel indole derivatives as potent anticancer active agents and apoptosis inducers

Reaction of 5-morphilinosulfonylisatin (1) with acetophenones (2a–e) afforded 3-hydroxy-3-substituted-2-oxoindoles 3a-e, when treated with acetic acid the expected 3-phenacylidene-2-oxoindoles 4a-d and 4-hydroxy-5′-(morpholinosulfonyl) spiro [chromene-2, 3′-indolin]-2′-one 6 were obtained. Isatin derivative (1) was stirred with cyano derivatives to produce the arylidines (7a-c), while under reflux condition, it gave pyrrolo[2,3–b]indoles (8, 9). Moreover, istain (1) reacted with pyrazolo-5-one or 3-substituted phenol in presence of malononitrile to afford spiroxindole derivatives (10a,b) and (11a,b). Also, compounds (10a,b) and (11a,b) were obtained through cyclization of (7a) with pyrazolo-5-one or 3-substituted phenol. The obtained compounds were identified by IR, ¹H NMR, ¹³C NMR and elemental analysis. Anticancer activity against three cancer cell lines (HepG-2, HCT-116 and MCF-7) were evaluated using sulforhodamine B assay method. Compounds 4b, 4c, 7a, 7c and 9 showed broad spectrum anticancer activity on the three tested cell lines with IC₅₀ values less than 10 µM. Cell cycle analysis was performed for the most promising derivatives, compounds 4b and 7c arrested HepG-2 cells at G2-M phase, while compounds 7a and 9 accumulated cells at G0-G1 phase, all of them induced apoptosis at priG1 phase in the range of (11.32–19.17%). Additionally compounds 4b, 7a and 9 showed more potent activity against EGFR than Lapatinib, their IC₅₀ values are from 0.019 to 0.026 µM while IC₅₀ of Lapatinib is 0.028 µM. Molecular docking studies were conducted to investigate the binding mode, amino acid interactions and free binding energy of these potent derivatives.     

Design,synthesis and biological evaluation of lapachol derivatives possessing indole scaffolds as topoisomerase I inhibitors

A series of novel lapachol derivatives possessing indole scaffolds was designed and synthesized. The in vitro anti-proliferative activity of these novel compounds was evaluated in Eca109 and Hela cell lines. Almost all the tested compounds showed manifested potent inhibitory activity against the two tested cancer cell lines. Topo I-mediated DNA relaxation activity indicated that these novel compounds have potent Topoisomerase I inhibition activity. The most potent compounds 4n and 4k demonstrated more cytotoxicity than camptothecin and was comparable to camptothecin in inhibitory activities on Topoisomerase I in our biological assay. In addition, the Hoechst 33342 staining method also showed that the complex can induce Hela cell apoptosis.