Biphenyl derivatives incorporating urea unit as novel VEGFR-2 inhibitors: Design,synthesis and biological evaluation

A series of novel biphenyl urea derivates were synthesized and investigated for their potential to inhibit vascular endothelial growth factor receptor-2 (VEGFR-2). In particular, A7, B3 and B4 displayed significant enzymatic inhibitory activities, with IC₅₀ values of 4.06, 4.55 and 5.26 nM. Compound A7 exhibited potent antiproliferative activity on several cell lines. SAR study suggested that the introduction of methyl at ortho-position of the biphenyl urea and tertiary amine moiety could improve VEGFR-2 inhibitory activity and antitumor effects. Molecular docking indicated that the urea moiety formed four hydrogen bonds with DFG residue. These biphenyl ureas could serve as promising lead compounds for further optimization.     

Discovery andw biological evaluation of novel 6,7-disubstituted-4-(2-fluorophenoxy)quinoline derivatives possessing 1,2,3-triazole-4-carboxamide moiety as c-Met kinase inhibitors

A series of 6,7-disubstituted-4-(2-fluorophenoxy)quinoline derivatives possessing 1,2,3-triazole-4-carboxamide moiety were designed, synthesized and evaluated for their in vitro biological activities against c-Met kinase and five typical cancer cell lines (A549, H460, HT-29, MKN-45 and U87MG). Most compounds showed moderate to excellent antiproliferative activity. In this study, a promising compound 34, with a c-Met IC₅₀ value of 1.04 nM, was identified as a multitargeted receptor tyrosine kinase inhibitor. The SAR analyses indicated that compounds with halogen group, especially fluoro group, at 4-position on the phenyl ring (moiety B) have potent antitumor activity, and methylation on the 5-atom linker played an important role in the c-Met enzymatic activity.     

Discovery of novel 4-(2-fluorophenoxy)quinoline derivatives bearing 4-oxo-1,4-dihydrocinnoline-3-carboxamide moiety as c-Met kinase inhibitors

A series of novel 4-(2-fluorophenoxy)quinoline derivatives containing 4-oxo-1,4-dihydrocinnoline-3-carboxamide moiety were designed, synthesized and evaluated for their in vitro biological activities against c-Met kinase and six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG and SMMC-7721). All the prepared compounds showed moderate to excellent antiproliferative activity, and the analysis of their structure–activity relationships indicated that 2-chloro or 2-trifluoromethyl substituted phenyl group on the 1-position of cinnoline ring was more favorable for antitumor activity. In this study, a promising compound 33, with a c-Met IC₅₀ value of 0.59 nM, was identified as a multitargeted receptor tyrosine kinase inhibitor.     

Design,synthesis and biological activities of Nilotinib derivates as antitumor agents

A novel class of Nilotinib derivatives, B1–B20, were synthesized in high yields using various substituted anilines. All the title compounds were evaluated for their inhibitory activities against Bcr–Abl and antiproliferative effects on human leukemia cell (K562). The pharmacological results indicated that some compounds exhibited promising anticancer activity. In particular, compound B14 containing tertiary amine side chain exhibited Bcr–Abl inhibitory activity similar to that of Nilotinib. It was suggested that the introduction of the tertiary amine moiety could improve Bcr–Abl inhibitory activity and antitumor effects.     

Cis-trimethoxystilbene,exhibits higher genotoxic and antiproliferative effects than its isomer trans-trimethoxystilbene in MCF-7 and MCF-10A cell lines

Stilbenes are a class of natural compounds with a wide variety of biological effects, such as antitumor activity. The best-known stilbene is resveratrol, whose clinical application is limited due to its low bioavailability. Methoxylated derivatives of this stilbene, including cis-trimethoxystilbene (cis-TMS) and trans-trimethoxystilbene (trans-TMS) have demonstrated more pronounced cytotoxic and anti-proliferative effects than resveratrol. Thus, the objective of this study is to evaluate and compare the cytotoxicity and antiproliferative effects of cis- and trans-TMS in MCF-7 and its normal counterpart MCF-10A. Both compounds were cytotoxic, genotoxic, and induced G2-M accumulation and cell death in the two cell lines. These results suggested that the genotoxicity of cis- and trans-TMS is involved in the reduction of cellular proliferation of MCF-7 and MCF-10A cells, but notably, such antiproliferative effects are more pronounced for cis- than trans-TMS.     

Synthesis and anticancer activity of novel 4-morpholino-7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine derivatives bearing chromone moiety

Herein, we designed and synthesized of a novel series of 7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine derivatives bearing chromone moiety (10a–j, 13a–j). All the compounds were evaluated for the IC₅₀ values against five cancer cell lines (A549, PC-3, MCF-7, Hela and HepG2). Seven of the target compounds exhibited moderate to excellent cytotoxicity. For these compounds, we tested their inhibitory activities against mTOR kinase, and four of them were tested their inhibitory activities against PI3Kα kinase in further. The results indicated that the optimized compound 10j showed excellent inhibitory activity and cytotoxicity against mTOR kinase, PI3Kα kinase and five cancer cell lines with IC₅₀ values of 1.1 μM, 0.92 μM and 8.77–14.3 μM. Structure–activity relationships (SARs) and docking studies indicated that the thiopyrano[4,3-d]pyrimidine scaffolds exerted little effect on antitumor activities of target compounds. Substitutions of chromone moiety at C-6 position with carboxyl were benefit to the antitumor activities.     

Development of novel ferulic acid derivatives as potent histone deacetylase inhibitors

Histone deacetylase inhibitors (HDACIs) offer a promising strategy for cancer therapy. The discovery of potent ferulic acid-based HDACIs with hydroxamic acid or 2-aminobenzamide group as zinc binding group was reported. The halogeno-acetanilide was introduced as novel surface recognition moiety (SRM). The majority of title compounds displayed potent HDAC inhibitory activity. In particular, FA6 and FA16 exhibited significant enzymatic inhibitory activities, with IC₅₀ values of 3.94 and 2.82 μM, respectively. Furthermore, these compounds showed moderate antiproliferative activity against a panel of human cancer cells. FA17 displayed promising profile as an antitumor candidate. The results indicated that these ferulic acid derivatives could serve as promising lead compounds for further optimization.     

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.     

Design,synthesis, and biological evaluation of novel aminopyrimidinylisoindolines as AXL kinase inhibitors

A novel series of aminopyrimidinylisoindoline derivatives 1a-w having an aminopyrimidine scaffold as a hinge region binding motif were designed and synthesized. Among them, six compounds showed potent inhibitory activities against AXL kinase with IC₅₀ values of submicromolar range. Especially, compound 1u possessing (4-acetylpiperazin-1-yl)phenyl moiety exhibited extremely excellent efficacy (IC₅₀?=?<0.00050?μM). Their in vitro antiproliferative activities were tested over five cancer cell lines. Most compounds showed good antiproliferative activities against HeLa cell line. The kinase panel profiling of 50 different kinases and the selected inhibitory activities for the representative compound 1u were carried out. The compound 1u exhibited excellent inhibitory activities (IC₅₀?=?<0.00050, 0.025, and 0.050?μM for AXL, MER, and TYRO3, respectively) against TAM family, together with potent antiproliferative activity against MV4-11 cell line (GI₅₀?=?0.10?μM) related to acute myeloid leukemia (AML).     

Synthesis of aminoquinazoline derivatives and their antiproliferative activities against melanoma cell line

The synthesis of a novel series of aminoquinazoline derivatives 1a–r and their antiproliferative activities against A375 human melanoma cell line were described. Among them, six compounds showed superior antiproliferative activities to Sorafenib as a reference compound. In particular, the representative compound 1q bearing chromen-4-one moiety exhibited excellent antiproliferative activity (IC₅₀ = 0.006 μM) and good selectivity over HS27 fibroblast cell line.     

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.     

Synthesis and antitumor activity of bis(hydroxymethyl)propionate analogs of pterostilbene in cisplatin-resistant human oral cancer cells

The aim of this study was to develop a new drug substance with low toxicity and effective inhibitory activity against cisplatin-resistant oral cancer. The naturally produced pterostilbene was selected as the lead compound for design and synthesis of a series of bis(hydroxymethyl)propionate-based prodrugs. All derivatives were screened for antiproliferative effects against the cisplatin-resistant oral squamous (CAR) cell line and the results indicated that several compounds demonstrated superior inhibitory activity compared with pterostilbene and resveratrol. Among them, the most promising compound, 12, was evaluated for in vivo antitumor activity in a CAR xenograft nude mouse model. Obvious antitumor activity was observed at the lowest oral dose (25?mg/kg/day). Increasing the dose of 12 to 100?mg/kg/day reduced the tumor size to 22% of the control group. Based on these findings as well as the extremely low toxicity seen in the in vivo studies, we believe that compound 12 could serve as a new lead for further development.     

New amide linked dimeric 1,2,3-triazoles bearing aryloxy scaffolds as a potent antiproliferative agents and EGFR tyrosine kinase phosphorylation inhibitors

A search for potent antiproliferative agents has prompted to design and synthesize aryloxy bridged and amide linked dimeric 1,2,3-triazoles (7a–j) by using 1,3-dipolar cycloaddition reaction between 2-azido-N-phenylacetamides (4a–e) and bis(prop-2-yn-1-yloxy)benzenes (6a–b) via copper (I)-catalyzed click chemistry approach with good to excellent yields. All the newly synthesized compounds have been screened for their in vitro antiproliferative activities against two human cancer cell lines. The compounds 7d, 7e, 7h, 7i and 7j have revealed promising antiproliferative activity against human breast cancer cell line (MCF-7), whereas, the compounds 7a, 7b, 7c, 7i and 7j were observed as potent antiproliferative agents against human lung cancer cell line (A-549). The active compounds against MCF-7 have been also analysed for their mechanism of action by the enzymatic study, which shows that the compounds 7d, 7h and 7j were acts as active EGFR tyrosine kinase phosphorylation inhibitors. In support to this biological study, the molecular docking as well as in silico ADME properties of all the newly synthesized hybrids were predicted.     

Discovery of novel 6,7-disubstituted-4-phenoxyquinoline derivatives bearing 5-(aminomethylene)pyrimidine-2,4,6-trione moiety as c-Met kinase inhibitors

A series of novel quinoline derivatives bearing 5-(aminomethylene)pyrimidine-2,4,6-trione moiety were designed, synthesized, and evaluated for their c-Met kinase inhibitory activities and antiproliferative activities against 5 cancer cell lines (HT-29, H460, MKN-45, A549, and U87MG) in vitro. Most compounds showed moderate to excellent potency, with the most promising analogue 45 (c-Met half-maximal inhibitory concentration [IC₅₀] = 1.15 nM) showing high selectivity versus 5 other tyrosine kinases, VEGFR-2, Flt-3, PDGFR-β, c-Kit, and EGFR. Structure–activity relationship studies indicated that electron-donating groups on the phenyl ring at the 3-position of pyrimidine-2,4,6-trione were required to increase the electron density on the 5-(aminomethylene)pyrimidine-2,4,6-trione moiety.     

Synthesis,antioxidant and antiproliferative activities of 1,3,4-thiadiazoles derived from phenolic acids

Two 2-amino-1,3,4-thiadiazoles containing phenolic hydroxyl groups were combined with different carboxylic acid chlorides giving sixteen amide derivatives with good antioxidant and antiproliferative potential. The compound 3′c with an adamantane ring displayed excellent DPPH radical scavenging activity and good cytotoxic activity against human acute promyelocytic leukemia HL-60 cells, while 1,3,4-thiadiazole 3′h with 4-chlorophenyl moiety was found to be the most effective in inhibition of survival of lung carcinoma A549 cells. All examined thiadiazoles except 3a and 3′a exerted higher cytotoxic activities on A549 and HL-60 cancer cells when compared with normal fibroblasts MRC-5, pointing to selectivity in their antiproliferative action. Some of the most active novel compounds 3c, 3′c, 3′g and 3′h induced significant increase in the percentage of HL-60 cells in the subG1 cell cycle phase in comparison with the control cells. The induction of cell death in HL-60 cells by these compounds was at least partially dependent on activation of caspase-3 and caspase-8. The compounds 3c and 3′c exerted strong antiangiogenic activity. Furthermore, compounds 3c, 3′c, 3′g and 3′h showed the ability to down-regulate the MMP2 and VEGFA expression levels in the treated HL-60 cells when compared with the control cell samples.     

Structure based drug design and in vitro metabolism study: Discovery of N-(4-methylthiophenyl)-N,2-dimethyl-cyclopenta[d]pyrimidine as a potent microtubule targeting agent

We report a series of tubulin targeting agents, some of which demonstrate potent antiproliferative activities. These analogs were designed to optimize the antiproliferative activity of 1 by varying the heteroatom substituent at the 4′-position, the basicity of the 4-position amino moiety, and conformational restriction. The potential metabolites of the active compounds were also synthesized. Some compounds demonstrated single digit nanomolar IC₅₀ values for antiproliferative effects in MDA-MB-435 melanoma cells. Particularly, the S-methyl analog 3 was more potent than 1 in MDA-MB-435 cells (IC₅₀?=?4.6?nM). Incubation of 3 with human liver microsomes showed that the primary metabolite of the S-methyl moiety of 3 was the methyl sulfinyl group, as in analog 5. This metabolite was equipotent with the lead compound 1 in MDA-MB-435 cells (IC₅₀?=?7.9?nM). Molecular modeling and electrostatic surface area were determined to explain the activities of the analogs. Most of the potent compounds overcome multiple mechanisms of drug resistance and compound 3 emerged as the lead compound for further SAR and preclinical development.     

Combination of 4-anilinoquinazoline,arylurea and tertiary amine moiety to discover novel anticancer agents

In present study, 4-anilinoquinazolines scaffold, arylurea and tertiary amine moiety were combined to design, synthesize gefitinib analogs and discover novel anticancer agents. A series of 4-anilinoquinazoline derivatives (1, 2, 3 and 4) bearing arylurea and tertiary amine moiety at its 6-position were synthesized. Their antiproliferative activities in vitro were evaluated via MTT assay against A431 cell and A549 cell. The SAR of the title compounds was discussed. The compounds 2d, 2i and 2j with potent antiproliferative activities were evaluated their inhibitory activity against EGFR-TK. Compound 2j displayed potent inhibitory activity against EGFR-TK. In addition, compound 2j, at 50 mg/kg, can completely inhibit cancer growth in established nude mouse A549 xenograft model in vivo. These results suggest that the 4-anilinoquinazoline derivatives bearing diarylurea and tertiary amino moiety at its 6-position can serve as anticancer agents and EGFR inhibitors.     

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.     

Functionalized 3-benzylidene-indolin-2-ones: Inducers of NAD(P)H-quinone oxidoreductase 1 (NQO1) with antiproliferative activity

Functionalized benzylidene-indolin-2-ones are widely associated with antiproliferative activity. The scaffold is not normally associated with chemoprevention in spite of the presence of a nitrogen-linked Michael acceptor moiety that may predispose members to induction of NQO1, a widely used biomarker of chemopreventive potential. To investigate this possibility, we have synthesized and evaluated a series of functionalized 3-benzylidene-indolin-2-ones for induction of NQO1 in murine Hepa1c1c7 cells as well as antiproliferative activity against two human cancer cell lines (MCF-7, HCT116). The benzylideneindolinones were found to be good inducers of NQO1 activity, with 85% of test compounds able to increase basal NQO1 activity by more than twofold at concentrations of ?10 μM. By contrast, fewer compounds (11%) tested at the same concentration were able to reduce cell viability by more than 50%. Structure activity relationships showed that the nitrogen linked Michael acceptor moiety was an essential requirement for both activities. This common feature notwithstanding, substitution of the 3-benzylidene-indolin-2-one core structure affected NQO1 induction and antiproliferative activities in dissimilar ways, underscoring different structural requirements for these two activities. Nonetheless, promising compounds (10, 42, 45–48) were identified that combine selective induction of NQO1 with potent antiproliferative activity. A potential advantage of such agents would be the ability to provide added protection to normal cells by the up-regulation of NQO1 and other phase II enzymes while simultaneously targeting neoplastic cells.     

Enantiomeric trans β-aryl-δ-iodo-γ-lactones derived from 2,5-dimethylbenzaldehyde induce apoptosis in canine lymphoma cell lines by downregulation of anti-apoptotic Bcl-2 family members Bcl-xL and Bcl-2

For many years, studies focused on developing new natural or synthetic compounds with antineoplastic activity have attracted the attention of researchers. An interesting group of such compounds seem to be those with both lactone moiety and an aromatic ring which, in addition to antimicrobial or antiviral activity, also exhibit antitumor properties. The study shows antitumor activity of two enantiomeric trans isomers of 5-(1-iodoethyl)-4-(2′,5′-dimethylphenyl)dihydrofuran-2-one. Our aim was to determine their antitumor activity manifested as an ability to induce apoptosis in selected canine cancer cell lines as well as to evaluate differences in their strength depending on the configuration of their stereogenic centers. The enantiomers (+)-(4R,5S,6R)-1 and (?)-(4S,5R,6S)-2 were found to induce classical caspase-dependent apoptosis through downregulation of the expression of anti-apoptotic proteins Bcl-xL and Bcl-2. Although the mechanism of apoptosis induction was the same for both enantiomers, they differed in their strength, as stronger antineoplastic activity in vitro was exhibited by isomer (+)-(4R,5S,6R)-1.