Nitric oxide-donating derivatives of hederacolchiside A1: Synthesis and biological evaluation in vitro and in vivo as potential anticancer agents

A series of nitric oxide (NO) donating derivatives of hederacolchiside A₁ bearing triterpenoid saponin motif were designed, synthesized and evaluated for their anticancer activity. All of the tested furoxan-based NO releasing compounds showed significant proliferation inhibitory activities. Especially compound 6a exhibited strong cytotoxicity (IC₅₀ = 1.6–6.5 μM) against four human tumor cell lines (SMMC-7721, NCI-H460, U251, HCT-116) in vitro and the highest level of NO releasing. Furthermore, compound 6a was revealed low acute toxicity to mice and weak haemolytic activity with potent tumor growth inhibition against mice H22 hepatocellular cells in vivo (51.5%).     

Glycyrrhetinic acid derivatives containing aminophosphonate ester species as multidrug resistance reversers that block the NF-κB pathway and cell proliferation

Novel NF-κB inhibitors based on Glycyrrhetinic acid (GA) derivatives containing aminophosphonate ester moieties were rationally designed and synthesized as well as evaluated their antitumor activities using MTT assay. Many target compounds showed potent antitumor activities against the tested human cancer cell lines including cisplatin-resistant cells, and exhibited significant inhibitory activity to the NF-κB with IC₅₀ values at micromolar concentrations in A549 cells, respectively. Among them, compound 12e possessed excellent antitumor activities against the tested human cancer cell lines and showed low cytotoxicity toward to human normal liver cells. Moreover, 12e caused obvious loss of MMP and significantly induced ROS production, and displayed inhibition of cell migration against A549 cells in vitro. Importantly, 12e arrested the cell cycle at the S phases and ultimately induced cell apoptosis in A549 cells through blockage of NF-κB signaling pathway. Our research provided an efficient strategy for targeting NF-κB antitumor drug development.     

Design,synthesis and evaluation of novel bivalent β-carboline derivatives as multifunctional agents for the treatment of Alzheimer's disease

To develop potent multi-target ligands against Alzheimer's disease (AD), a series of novel bivalent β-carboline derivatives were designed, synthesized, and evaluated. In vitro studies revealed these compounds exhibited good multifunctional activities. In particular, compounds 8f and 8g showed the good selectivity potency on BuChE inhibition (IC₅₀?=?1.7 and 2.7?μM, respectively), Aβ_1-42 disaggregation and neuroprotection. Compared with the positive control resveratrol, 8f and 8g showed better activity in inhibiting Aβ_1-42 aggregation, with inhibitory rate 82.7% and 85.7% at 25?μM, respectively. Moreover, compounds 8e, 8f and 8g displayed excellent neuroprotective activity by ameliorating the impairment induced by H₂O₂, okadaic acid (OA) and Aβ_1-42 without cytotoxicity in SH-SY5Y cells. Thus, the present study evidently showed that compounds 8f and 8g are potent multi-functional agents against AD and might serve as promising lead candidates for further development.     

Discovery and optimization of 3,4,5-trimethoxyphenyl substituted triazolylthioacetamides as potent tubulin polymerization inhibitors

Based on our previous research, three series of new triazolylthioacetamides possessing 3,4,5-trimethoxyphenyl moiety were synthesized, and evaluated for antiproliferative activities and inhibition of tubulin polymerization. The most promising compounds 8b and 8j demonstrated more significant antiproliferative activities against MCF-7, HeLa, and HT-29 cell lines than our lead compound 6. Moreover, analogues 8f, 8j, and 8o manifested more potent antiproliferative activities against HeLa cell line with IC₅₀ values of 0.04, 0.05 and 0.16?μM, respectively, representing 100-, 82-, and 25-fold improvements of the activity compared to compound 6. Furthermore, the representative compound, 8j, was found to induce significant cell cycle arrest at the G₂/M phase in HeLa cell lines via a concentration-dependent manner. Meanwhile, compound 8b exhibited the most potent tubulin polymerization inhibitory activity with an IC₅₀ value of 5.9?μM, which was almost as active as that of CA-4 (IC₅₀?=?4.2?μM). Additionally, molecular docking analysis suggested that 8b formed stable interactions in the colchicine-binding site of tubulin.     

Novel DNA intercalators without basic side chains as efficient antitumor agents: Design,synthesis and evaluation of benzo-[c,d]-indol-malononitrile derivatives

Several 2-(substituted benzo[c,d]indol-2(1H)-ylidene)malononitriles have been designed and synthesized. Their DNA binding, antitumor and DNA damaging properties were evaluated. All the compounds exhibited efficient antitumor activities with preference to be against the tumor cell line 7721 rather than the tumor cell line MCF-7. Compound 1f could intercalate into DNA entirely presumably by the good conjugation of carbonyl group with benzo[c,d]indol moiety. What’s more, 1f exhibited potent toxicity against MCF-7 cells with IC₅₀ at 0.003 μM and against 7721 cells at 0.115 μM, respectively.     

Novel 3,4-dihydro-4-oxoquinazoline-based acetohydrazides: Design,synthesis and evaluation of antitumor cytotoxicity and caspase activation activity

In search for novel small molecules with antitumor cytotoxicity via activating procaspase-3, we have designed and synthesized three series of novel (E)-N′-benzylidene-4-oxoquinazolin-3(4H)-yl)acetohydrazides (5a-j, 6a-h, and 7a-h). On the phenyl ring ò the benzylidene part, three different substituents, including 2-OH-4-OCH₃, 4-OCH₃, and 4-N(CH₃)₂, were introduced, respectively. Biological evaluation showed that the acetohydrazides in series 5a-j, in which the phenyl ring of the benzylidene part was substituted by 2-OH-4-OCH₃ substituent, exhibited potent cytotoxicity against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung). Most of the compounds, in this series, especially compounds 5c, 5b and 5h, also significantly activated caspase-3 activity. Among these, compound 5c displayed 1.61-fold more potent than PAC-1 as caspase-3 activator. Cell cycle analysis showed that compounds 5b, 5c, and 5h significantly arrested the cell cycle in G1 phase. Further apoptotic studies also demonstrated compounds 5b, 5c, and 5h as strong apoptotic cell death inducers. The docking simulation studies showed that these compounds could activate procaspase via chelating Zn²⁺ ion bound to the allosteric site of the zymogen.     

Design,synthesis and anticancer evaluation of 1H-pyrazolo[3,4-d]pyrimidine derivatives as potent EGFRWT and EGFRT790M inhibitors and apoptosis inducers

In our attempt to develop effective EGFR-TKIs, two series of 1H-pyrazolo[3,4-d]pyrimidine derivatives were designed and synthesized. All the newly synthesized compounds were evaluated in vitro for their inhibitory activities against EGFR^WT. Compounds 15_b, 15_j, and 18_d potently inhibited EGFR^WT at sub-micro molar IC₅₀ values comparable to that of erlotinib. Moreover, thirteen compounds that showed promising IC₅₀ values against EGFR^WT were tested in vitro for their inhibitory activities against mutant EGFR^T790M. Compounds 17_d and 17_f exhibited potent inhibitory activities towards EGFR^T790M comparable to osimertinib. Compounds that showed promising IC₅₀ values against EGFR^WT were further tested for their anti-proliferative activities against three cancer cell lines bearing EGFR^WT (MCF-7, HepG2, A549), and two cancer cell lines bearing EGFR^T790M (H1975 and HCC827). Compounds 15_g, 15_j, 15_n, 18_d and 18_e were the most potent anticancer agents against the EGFR^WT containing cells, while compounds 15_e, 17_d and 17_f showed promising anti-proliferative activities against EGFR^T790M containing cells. Furthermore, the most active compound 18_d was selected for further studies regarding to its effects on cell cycle progression and induction of apoptosis in the HepG2 cell line. The results indicated that this compound is good apoptotic agent and arrests G₀/G₁and G₂/M phases of cell cycle. Finally, molecular docking studies were performed to investigate binding pattern of the synthesized compounds with the prospective targets, EGFR^WT (PDB: 4HJO) and EGFR^T790M (PDB: 3W2O).     

Design,synthesis and molecular modeling studies of new series of antitumor 1,2,4-triazines with potential c-Met kinase inhibitory activity

The receptor tyrosine kinase c-Met is an attractive target for therapeutic treatment of cancers nowadays. Herein we describe the design and synthesis of a novel series of 1,2,4-triazine derivatives based on our lead NCI 748494/1, possessing different N-linkers to aromatic and heterocyclic rings. In addition, a molecular hybrid series combining the 1,2,4-triazine scaffold to the well-known anticancer drug 6-mercaptopurine (6-MP) was synthesized in order to explore its “double-drug” antitumor effect. The synthesized compounds were evaluated for their in vitro antitumor activity against three c-Met addicted cancer cell lines (A549, HT-29 and MKN-45). Most compounds showed moderate to excellent antitumor activity. Compound 3d showed potent inhibitory activity more than reference Foretinib, BMS-777607 and NCI 748494/1 with IC₅₀ values in the range 0.01–0.31 µM against the cancer cell lines. The calculated IC₅₀ of 3d against c-Met kinase was found to be 2.71 µM, which is more potent than NCI 748494/1 (IC₅₀ = 31.70 µM). Docking studies were performed to identify the binding mode of 3d with c-Met kinase domain in comparison to moderate and weak derivatives. The present study clearly demonstrates that 1,2,4-triazine ring exhibits promising antitumor activity and the double-drug optimization strategy led to identifying 3d as a potent c-Met kinase inhibitor suitable for further development.     

Design,synthesis and biological evaluation of tripeptide boronic acid proteasome inhibitors

A series of tripeptide boronate proteasome inhibitors were designed and synthesized on the basis of our previously built tripeptide aldehyde 3D-QSAR models. All the synthesized compounds were evaluated for their proteasome-inhibitory activities in an isolated 20S rabbit proteasome, and selected compounds were evaluated for their antitumor activities in vitro against four human cancer cell lines. Biological results showed bulky and negative substituents at P² position improved the proteasome-inhibitory potency obviously, which completely conformed to the theoretical models, while those at P³ position thoroughly deviated from the 3D-QSAR model. Most of the screened compounds showed less than 1 nM inhibitory potency and high selectivity against 20S proteasome, of which 7f is the most potent (IC₅₀ = 0.079 nM) and twofold more active than bortezomib (IC₅₀ = 0.161 nM). Cell viability indicated hydrophilic 4-hydroxyphenyl substituent at P² or P³ position was not favorable to the cellular activities. Especially for the two hematologic cancer cell lines, HL-60 and U266, 7f inhibited them at the level of less than 10 nM and was more potent than the control bortezomib. It is being considered a promising new lead to be developed for the treatment of various cancers.     

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 biological evaluation of novel 5,6-dihydropyrimido[4,5-f]quinazoline derivatives as potent CDK2 inhibitors

As serine/threonine kinase, the cyclin dependent kinase 2 (CDK2) is a promising target for various diseases such as cerebral hypoxia, cancer, and neurodegenerative diseases. Here we reported the structure-based synthesis and biological evaluation of novel 5,6-dihydropyrimido[4,5-f]quinazoline derivatives as CDK2 inhibitors, which exhibited potent CDK2 inhibitory activities, as well as anticancer activities in low concentration against two human cancer cell lines (MCF-7 and HCT116). In particular, compounds 11a and 11f (IC₅₀ values of 0.11 and 0.09?μM for CDK2, respectively) have demonstrated significantly inhibitory potency against CDK2 and have showed great inhibitory activities against MCF-7 and HCT116 cell lines.     

Synthesis and biological evaluation of novel 1-substituted 3-(3-phenoxyprop-1-yn-1-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-amines as potent Bruton's tyrosine kinase (BTK) inhibitors

A new series of 1-substituted pyrazolopyrimidine derivatives were synthesized as potent BTK inhibitors and they were evaluated by enzyme-based assay and anti-proliferation against multiple B-cell lymphoma cell lines in vitro. Among these compounds, 9h exhibited the highest potency against BTK enzyme, with IC₅₀ value of 4.2?nM. In particular, 8 and 9f performed better inhibition against the proliferation of B lymphoma cell lines DOHH2 and WSU-DLCL2 than the clinical drug ibrutinb. In addition, the test toward the normal PBMC cells showed that 8 possessed low cell cytotoxicity. All these explorations indicated that 8 could serve as a valuable anti-tumor agent for B-cell lymphoblastic leukemia treatment.     

Discovery of novel 4(1H)-quinolone derivatives as potential antiproliferative and apoptosis inducing agents

A series of novel 4(1H)-quinolone derivatives was synthesized and evaluated for antiproliferative activity in vitro. The results showed that these compounds exhibited more potent antiproliferative effect against a panel of human tumor cell lines than the lead compound 7-chloro-4(1H)-quinolone 1. Compound 7e was found to be the most potent antiproliferative agent and to exhibit selective cytotoxic activity against HepG2 cell lines with IC₅₀ value lower than 1.0 μM. Annexin V/FITC-PI assay showed that compound 7e induced apoptosis in HepG2 cells with a dose-dependent manner. Western blotting analysis indicated that compound 7e induced cell cycle arrest in G2/M phase by p53-depedent pathway.     

Design,synthesis, and biological evaluation of 4-phenoxyquinoline derivatives as potent c-Met kinase inhibitor

A series of novel 4-phenoxyquinoline derivatives containing 3-oxo-3,4-dihydro-quinoxaline moiety were synthesized and evaluated for their antiproliferative activity against five human cancer cell lines (A549, H460, HT-29, MKN-45 and U87MG) in vitro. Most of the tested compounds exhibited more potent inhibitory activities than the positive control foretinib. Compound 1b, 1s and 1t were further examined for their inhibitory activity against c-Met kinase. The most promising compound 1s (with c-Met IC₅₀ value of 1.42 nM) showed remarkable cytotoxicity against A549, H460, HT-29, MKN45 and U87MG cell lines with IC₅₀ values of 0.39 μM, 0.18 μM, 0.38 μM, 0.81 μM, respectively. Their preliminary structure-activity relationships (SARs) study indicated that the replacement of the aromatic ring with the cyclohexane improved their antiproliferative activity.     

Novel benzotriazole N-acylarylhydrazone hybrids: Design,synthesis, anticancer activity,effects on cell cycle profile,caspase-3 mediated apoptosis and FAK inhibition

A series of novel benzotriazole N-acylarylhydrazone hybrids was synthesized according fragment-based design strategy. All the synthesized compounds were evaluated for their anticancer activity against 60 human tumor cell lines by NCI (USA). Five compounds: 3d, 3e, 3f, 3o and 3q exhibited significant to potent anticancer activity at low concentrations. Compound 3q showed the most prominent broad-spectrum anticancer activity against 34 tumor cell lines, with mean growth inhibition percent of 45.80%. It exerted the highest potency against colon HT-29 cell line, with cell growth inhibition 86.86%. All leukemia cell lines were highly sensitive to compound 3q. Additionally, compound 3q demonstrated lethal activity to MDA-MB-435 belonging melanoma. Compound 3e exhibited the highest anticancer activity against leukemic CCRF-CEM and HL-60(TB) cell lines, with cell growth inhibition 86.69% and 86.42%, respectively. Moreover, it exerted marked potency against ovarian OVCAR-3 cancer cell line, with cell growth inhibition 78.24%. Four compounds: 3d, 3e, 3f and 3q were further studied through determination of IC₅₀ values against the most sensitive cancer cell lines. The four compounds exhibited highly potent anticancer activity against ovarian cancer OVCAR-3 and leukemia HL-60 (TB) cell lines, with IC₅₀ values in nano-molar range between 25 and 130 nM. They showed 18–2.3 folds more potent anticancer activity than doxorubicin. The most prominent compound was 3e, (IC₅₀ values 29 and 25 nM against OVCAR-3 and HL-60 (TB) cell lines, respectively), representing 10 and 18 folds more potency than doxorubicin. The anti-proliferative activity of these four compounds appeared to correlate well with their ability to inhibit FAK at nano-molar range between 44.6 and 80.75 nM. Compound 3e was a potent, inhibitor of FAK and Pyk2 activity with IC₅₀ values of 44.6 and 70.19 nM, respectively. It was 1.6 fold less potent for Pyk2 than FAK. Additionally, it displayed inhibition in cell based assay measuring phosphorylated-FAK (IC₅₀ = 32.72 nM). Inhibition of FAK enzyme led to a significant increase in the level of active caspase-3, compared to control (11.35 folds), accumulation of cells in pre-G1 phase and annexin-V and propidium iodide staining in addition to cell cycle arrest at G2/M phase indicating that cell death proceeded through an apoptotic mechanism.     

Synthesis and antitumor activities of novel hybrid molecules containing 1,3,4-oxadiazole and 1,3,4-thiadiazole bearing Schiff base moiety

A series of novel hybrid molecules containing 1,3,4-oxadiazole and 1,3,4-thiadiazole bearing Schiff base moiety were designed, synthesized and evaluated for their in vitro antitumor activities against SMMC-7721, MCF-7 and A549 human tumor cell lines by CCK-8 assay. The bioassay results demonstrated that most of the tested compounds showed potent antitumor activities, and some compounds exhibited stronger effects than positive control 5-fluorouracil (5-FU) against various cell lines. Among these compounds, compound 8d showed the best inhibitory effect against SMMC-7721 cells, with IC₅₀ value of 2.84 μM. Compounds 8k and 8n displayed highly effective antitumor activities against MCF-7 cells, with IC₅₀ values of 4.56 and 4.25 μM, respectively. Compounds 8a and 8n exhibited significant antiproliferative activity against A549 cells, with IC₅₀ values of 4.11 and 4.13 μM, respectively. The pharmacological results suggest that the substituents of phenyl ring on the 1,3,4-oxadiazole are vital for modulating antiproliferative activities against various tumor cell lines.     

Synthesis,cytotoxicity, and in vivo antitumor activity study of parthenolide semicarbazones and thiosemicarbazones

Parthenolide is an important sesquiterpene lactone with potent anticancer activities. In order to further improve its biological activity, a series of parthenolide semicarbazone or thiosemicarbazone derivatives was synthesized and evaluated for their anticancer activity. Derivatives were tested in vitro against 5 human tumor cell lines, and many of these showed higher cytotoxicity than parthenolide. Five compounds were further studied for their antitumor activity in mice. The in vivo result indicated that compound 4d showed both promising antitumor activity against mice colon tumor and small side effects on immune systems. The cell apoptosis and cell cycle distribution of compound 4d were also studied. Molecular docking studies revealed multiple interactions between 4d and NF-κB. Our findings demonstrate the potential of semicarbazones as a promising type of compounds with anticancer activity.     

Novel carbazole sulfonamide derivatives of antitumor agent: Synthesis,antiproliferative activity and aqueous solubility

The current optimization of IG-105 (3) on the carbazole-ring provided a series of new carbazole sulfonamides derivatives 13a–13m. All of the compounds have been evaluated against HepG2 cells (hepatoma cancer) for antiproliferative activity. Compounds that showed activity better or comparable to that of 3 versus HepG2 were evaluated against MCF-7 (breast cancer), MIA PaCa-2 (pancreatic cancer), and Bel-7402 (hepatoma/liver cancer) for antiproliferative activity. Of the seven compounds selected for further study five (13b, 13g, 13j, 13k and 13l) were found to give IC₅₀ values against the four cell lines comparable to those for 3. Two compounds (13f and 13i) were more active than 3 and their activity against HepG2 and MCF-7 (IC₅₀:0.01–0.07 μM) approached that of the positive controls podophyllotoxin (podo) and CA-4. Most of compounds showed aqueous solubility (0.11–19.60 μg/mL at pH 7.4 and 2.0) better than 3. These promising results warrant further development of new compounds 13f and 13i as potential potent antitumor drug candidates.     

Synthesis and bioevaluation of 6-chloropyridazin-3-yl hydrazones and 6-chloro-3-substituted-[1,2,4]triazolo[4,3-b]pyridazines as cytotoxic agents

An efficient synthesis of a series of 6-chloro-3-substituted-[1,2,4]triazolo[4,3-b]pyridazines is described via intramolecular oxidative cyclization of various 6-chloropyridazin-3-yl hydrazones with iodobenzene diacetate. The structures of the newly synthesized compounds were assigned on the basis of elemental analysis, IR, NMR (¹H and ¹³C) and mass spectral data. All the thirty three compounds 3a-q and 4b-q synthesized in the present study were evaluated for their in vitro cytotoxic activities against two Acute Lymphoblastic Leukemia (ALL) cell lines named, SB-ALL and NALM-6, and a human breast adenocarcinoma cell lines (MCF-7). The results revealed that triazoles 4 exhibit better cytotoxicity than their hydrazone precursors 3. Among triazoles, compounds 4f, 4j and 4q exhibited potent cytotoxic activity against SB-ALL and NALM-6 with IC₅₀ values in the range of ∼1.64–5.66 μM and ∼1.14–3.7 μM, respectively, compared with doxorubicin (IC₅₀ = 0.167 μM, SB-ALL). Compounds 4f, 4j and 4q were subjected to apoptosis assay after 48 h treatment and these compounds induced apoptosis of NALM-6 cells via caspase 3/7 activation. Results revealed that compound 4q represents potential promising lead.