Synthesis and cytotoxicity studies of novel 2-Hydrazonylpyrido[2,3-b]pyrazin-3(4H)-ones

In an attempt to develop potent antitumor agents, a series of novel 2‐hydrazonylpyrido[2,3‐b]pyrazin‐3(4H)‐one derivatives were designed and synthesized. All the prepared compounds were screened for their cytotoxic activities against A549, MDA‐MB‐231 and HT‐29 cell lines in vitro. Pharmacological data indicated that five of the target compounds showed cytotoxicity against A549 cell line below a concentration of 1 µM. Compound 15g was the most potent one with IC₅₀ values of 0.19, 2.11 and 2.15 µM against A549, MDA‐MB‐231 and HT29 cell lines, respectively.     

Synthesis and biological evaluation of novel imidazopyrimidin‐3‐amines as anticancer agents

Groebke–Blackburn–Bienayme reaction has been utilized for the synthesis of new imidazo[1,2‐a]pyrimidine derivatives as novel anticancer agents. The cytotoxic activities of compounds were evaluated against human cancer cell lines including MCF‐7, T‐47D, and MDA‐MB‐231, compared with etoposide as the standard drug. Among the tested compounds, hydroxy‐ and/or methoxy‐phenyl derivatives ( 6a–c and 6k ) with IC₅₀ values of 6.72–14.36 μm were more potent than etoposide against all cell lines. The acridine orange/ethidium bromide double staining and DNA fragmentation studies demonstrated that the cytotoxic effect of 3‐hydroxy‐4‐methoxyphenyl derivative 6c is associated with apoptosis in cancer cells.     

Synthesis and cytotoxic evaluation of some new phthalazinylpiperazine derivatives

A new series of 1,4‐disubstituted phthalazinylpiperazine derivatives 7a–f , 12a–f and 20a–f were designed and synthesized in order to develop potent and selective antitumor agents. The target compounds were screened for their cytotoxic activities against A549, HT‐29 and MDA‐MB‐231 cancer cell lines in vitro. Among them, compounds 7a–f exhibited excellent selectivity for MDA‐MB‐231 with IC₅₀ values ranging from 0.013 µM to 0.079 µM. The most promising compound, 7e (IC₅₀ = 2.19 µM, 2.19 µM, 0.013 µM), was 9.3, 10, and 4.9 × 10³ times more active than vatalanib (IC₅₀ = 20.27 µM, 21.96 µM, 63.90 µM), respectively.     

Synthesis and antitumor activity of 2‐isocamphanyl thiosemicarbazone derivatives via ROS‐enhanced mitochondrial damage

A series of novel 2‐isocamphanyl thiosemicarbazone derivatives were synthesized and characterized by ¹H NMR, ¹³C NMR, and HRMS. In in vitro anticancer activity, most derivatives showed considerable cytotoxic activity against four cancer cell lines (RPMI‐8226, A549, MDA‐MB‐231, and HepG2 cancer cells) and showed low toxicity against human gastric mucosal cells (GES‐1). Among them, compound 4h exhibited excellent antitumor activity against the tested cancer cells with IC₅₀ values of 0.4, 1.1, 1.6, and 1.7 μM for MDA‐MB‐231, RPMI‐8226, A549, and HepG2, respectively. Further, mechanism studies indicated that compound 4h induced apoptosis in MDA‐MB‐231 cells through enhancing reactive oxygen species levels, inducing mitochondrial membrane potential decrease, and influencing the expression of Bax, Bcl‐2, caspase‐3, and caspase‐9.     

Anticancer activity of gallic acid template‐based benzylidene indanone derivative as microtubule destabilizer

Benzylidene indanones have been designed and synthesized from gallic acid, a plant phenolic acid as possible anticancer agent. The best analogue of the series, that is, 3‐(3′,4′,5′‐trimethoxyphenyl)‐4,5,6‐trimethoxy‐2‐(4?‐nitrobenzylidene)‐indan‐1‐one ( 8 ) exhibited potent cytotoxicity (IC₅₀=3–10 μm ) against several human cancer cell lines through microtubule destabilization (IC₅₀=1.54 μm ) after occupying colchicine‐binding site of β‐tubulin. In cell cycle analysis, compound 8 exerted G2/M phase arrest in both MCF‐7 and MDA‐MB‐231 cells and induced apoptosis. It reduced 34.8% solid tumor in in vivo Ehrlich ascite carcinoma in Swiss albino mice at 30 mg/kg dose. In acute oral toxicity experiment, it was tolerable up to 300 mg/kg doses in Swiss albino mice. The lead compound 8 needs to be optimized for better activity.     

Synthesis,molecular docking and biological evaluation of 1‐phenylsulphonyl‐2‐(1‐methylindol‐3‐yl)‐benzimidazole derivatives as novel potential tubulin assembling inhibitors

A series of new 1‐phenylsulphonyl‐2‐(1‐methylindol‐3‐yl)‐benzimidazole derivatives were designed, synthesized and evaluated as potential inhibitors of tubulin polymerization and anthropic cancer cell lines. Among them, compound 33 displayed the most potent tubulin polymerization inhibitory activity in vitro (IC₅₀ = 1.41 μM) and strong antiproliferative activities against A549, Hela, HepG2 and MCF‐7 cell lines in vitro with GI₅₀ value of 1.6, 2.7, 2.9 and 4.3 μM, respectively, comparable with the positive control colchicine (GI₅₀ value of 4.1, 7.2, 9.5 and 14.5 μM, respectively) and CA‐4 (GI₅₀ value of 2.2, 4.3, 6.4 and 11.4 μM, respectively). Simultaneously, we evaluated that compound 33 could effectively induce apoptosis of A549 associated with G2/M phase cell cycle arrest. Immunofluorescence microscopy also clearly indicated compound 33 a potent antimicrotubule agent. Docking simulation showed that compound 33 could bind tightly with the colchicine‐binding site and act as a tubulin inhibitor. Three‐dimensional‐QSAR model was also built to provide more pharmacophore understanding that could be used to design new agents with more potent tubulin assembling inhibitory activity in the future.     

Synthesis and Biological Evaluation of Distamycin Analogues – New Potential Anticancer Agents

Eight of analogues of distamycin, potential minor‐groove binders, were synthesized and tested for in‐vitro cytotoxicity towards human breast cancer cells MCF‐7 and MDA‐MB‐231. The method of synthesis is simple and convenient. All of the compounds 1 – 8 showed antiproliferative and cytotoxic effects against both cell lines in the range 3.47 to 12.53 μM for MDA‐MB‐231 and 4.35 to 12.66 μM for MCF‐7. All compounds demonstrated activity against DNA topoisomerases I and II at a concentration of 50 μM. The ethidium bromide assay showed that these compounds bind to plasmid pBR322, yet weaker than distamycin. Further investigations concerning the mechanism of cytotoxicity are now in progress, but the IC₅₀ values suggest that synthetic distamycin analogues with a free amino group, 3 – 4 and 7 – 8 , can serve as potential carriers of strong acting elements, e. g. alkylating groups.     

Anti-tumor activity of new artemisinin-chalcone hybrids

In an attempt to develop potent and selective anti‐tumor agents, three new series of artemisinin–chalcone hybrids 10a – 10g , 11a – 11g and 12a–12h were designed, synthesized and screened for their anti‐tumor activity against five cell lines (HT‐29, A549, MDA‐MB‐231, HeLa and H460) in vitro. Among compounds 10a–g and 11a–11g , most of them displayed enhanced activity and good selectivity toward HT‐29 and HeLa cell lines with IC₅₀ values ranging from 0.12 to 0.85 µM as compared with DHA (dihydroartemisinin). Compounds 10a and 11a are most active toward HeLa cells with IC₅₀ values of 0.12 and 0.19 µM. The results revealed that the presence of chalcone moiety is beneficial to their activity and selectivity. In addition, compounds 12a ‐ 12h containing a ‘reversed chalcone’ moiety showed only slight improvement in activity than those of DHA.     

The application of tandem aza-wittig reaction to synthesize artemisinin-guanidine hybrids and their anti-tumor activity

Three series of novel artemisinin–guanidine hybrids 4a–4f , 8a–8h and 9a–9h have been facilely synthesized via four‐component reaction (aza‐Wittig reaction) and evaluated for their anti‐tumor activities against A549, HT‐29 and MDA‐MB‐231 cell lines in vitro. All of the tested compounds showed enhanced anti‐tumor activities with IC₅₀ values ranging from 0.02 µM to 12.0 µM as compared to DHA (dihydroartemisinin). Among them, artemisinin derived dimers, compounds 9b (IC₅₀ = 0.05 µM), 9d (IC₅₀ = 0.06 µM) and 9f (IC₅₀ = 0.02 µM) were found to be most active against HT29 cells.     

Hemisynthesis,Antitumoral Effect,and Molecular Docking Studies of Ferutinin and Its Analogues

The natural product ferutinin was shown to act as an agonist to estrogen receptor ERα and agonist/antagonist to ERβ featuring a weak antiproliferative activity toward breast cancer cells. To enhance this activity, ferutinin analogues were synthesized by esterification of jaeschkenadiol with different acids. These compounds were assayed for their in vitro antiproliferative activity against estrogen‐dependent (MCF‐7) and estrogen‐independent (MDA‐MB‐231) breast cancer cell lines. Among the compounds, 3c’ exhibited a potent inhibitory selective activity against MCF‐7 with IC₅₀ value of 1 μm . Docking simulation of 3c’ in the ligand binding domain of the ERs indicated a potential antagonism interaction with both ER subtypes. Functional assay showed that 3c’ binds as an antagonist to ERα protein while ferutinin acts as an agonist.     

Anticancer Activity of New Synthetic α‐Methylene‐δ‐Lactones on Two Breast Cancer Cell Lines

Natural products are important leads in drug discovery. The search for effective plant‐derived anticancer agents or their synthetic analogues has continued to be of interest to biologists and chemists for a long time. In this report, cytotoxicity and anticancer activity of new synthetic α‐methylene‐δ‐lactones was tested against two breast cancer cell lines, invasive, hormone‐independent MDA‐MB‐231 and hormone‐dependent MCF‐7. Cytotoxicity was examined using MTT assay. The ability to induce apoptosis and changes in mitochondrial membrane potential was studied by flow cytometry. The expression levels of pro‐ and anti‐apoptotic genes were determined by quantitative real‐time PCR. Cancer cell migration and invasion were assessed by wound healing and Matrigel assays. Additionally, secretion of proteins associated with invasiveness, metalloproteinase‐9 (MMP‐9) and urokinase plasminogen activator (uPA) was investigated using commercial ELISA kits and MMP‐9 activity by gelatin zymography. A natural sesquiterpene lactone, parthenolide, was used as a positive control. Screening results showed all four analogues to be highly cytotoxic. The most potent compound of the series, 1‐isopropyl‐2‐methylene‐1,2‐dihydrobenzochromen‐3‐one, designated DL‐3, which reduced the number of viable MDA‐MB‐231 and MCF‐7 cells with the IC₅₀ values of 5.3 μM and 3.54 μM, respectively, was selected for further research. DL‐3 activated the intrinsic pathway of apoptosis, associated with the loss of mitochondrial membrane potential and changes in Bax/Bcl‐2 ratio. DL‐3 also inhibited the movement of both types of breast cancer cells. Suppression of cell migration and invasion was the result of the decreased secretion of enzymes responsible for the degradation of the extracellular matrix, MMP‐9 and uPA. These findings show that the synthetic α‐methylene‐δ‐lactone, DL‐3, displays potential to be further explored in the development of new anticancer agents.     

Synthesis of new pyrazolo[3,4‐d]pyrimidine derivatives and evaluation of their anti‐inflammatory and anticancer activities

This study reports the synthesis of two series of new purine bioisosteres comprising a pyrazolo[3,4‐d]pyrimidine scaffold linked to piperazine moiety through different amide linkages. The newly synthesized compounds were evaluated for anticancer activity against four cell lines (MDA‐MB‐231, MCF‐7, SF‐268, B16F‐10) and cyclooxygenase (COX‐2) protein expression inhibition in lipopolysaccharide (LPS)‐activated rat monocytes. The results revealed that most of the synthesized compounds showed moderate‐to‐high cytotoxic activity against at least one cell line, with compound 10b being the most active against all used cell lines (IC₅₀ values 5.5–11 μg/ml) comparable to cisplatin. In addition, six of these compounds ( 7b, 10a–d, and 12c ) demonstrated inhibition of LPS‐induced COX‐2 protein expression at low concentration (25 μg/ml) as compared to the control non‐stimulated cells and showed a COX‐2 selectivity index range comparable to diclofenac sodium. The overall results indicate that many of these pyrazolopyrimidine derivatives possess in vitro anti‐inflammatory and anticancer activities at varying doses, and the most active compounds will be subjected to in vivo pharmacological evaluation.     

Synthesis and Biological Evaluation of Benzo[d][1,3]Dioxol‐5‐yl Chalcones as Antiproliferating Agents

A series of chalcone derivatives were designed, synthesized, and evaluated for their cytotoxic potential. These molecules have showed promising cytotoxic activity with IC₅₀ values ranging from 5.24 to 63.12 μm . Among them, conjugates 16k , 16m and 16t showed significant antiproliferative activity with IC₅₀ values ranging from 5.24 to 10.39  μ m in MDA‐MB‐231 cell line. These compounds were further investigated for their effect on cell membrane blebbing, chromatin condensation, DNA fragmentation, Hoechst staining, annexin V, and cell cycle arrest (G2/M). The Western blot experiments revealed up regulation of pro‐apoptotic Bax and downregulation of antiapoptotic Bcl‐2. The studies also indicated reduction of mitochondrial membrane potential and increase in the levels of caspase‐3 and caspase‐7.     

Design,synthesis, and evaluation of the anticancer activity of 2‐amino‐aryl‐7‐aryl‐benzoxazole compounds

A series of 2‐amino‐aryl‐7‐aryl‐benzoxazole derivatives have been designed, synthesized, and evaluated as anticancer agents. Fourteen of the compounds exhibited cytotoxic effects toward human A549 lung cancer cells. We found 12l was the most potent with an EC₅₀ of 0.4 μm , equivalent to the anticancer drug doxorubicin, but had low selectivity following cross screening in monkey kidney Vero cells. Eight of the most potent or most selective compounds were further profiled in additional cell lines (MCF7, NCI‐H187, and KB) to better understand their cytotoxic activity. Only compound 12l had a measurable EC₅₀ in a single cell line (3.3 μm in the KB cell line). Taken together, this data suggest the series as a whole display specific cytotoxicity toward A549 cells. Cheminformatics searches pointed to JAK2 as a possible target. A subset of compounds assayed at this target showed IC₅₀s ranging from 10 to 0.08 μm ; however, no clear correlation between JAK2 potency and A549 cytotoxicity was observed.     

In-vitro antiproliferative activity of benzopyranone derivatives in comparison with standard chemotherapeutic drugs

The cytotoxic activities of five new benzopyranone derivatives containing basic amino side chain are described. Their cytotoxicities against ER(+) MCF‐7 and ER(–) MDA‐MB‐231 human breast cancer cell lines, and Ishikawa human endometrial cell line were determined after 72 h drug exposure employing CellTiter‐Glo assay at concentrations ranging from 0.01–1.0 × 10⁵ nM. The antiproliferative activities of these compounds were compared to tamoxifen (TAM), 4‐hydroxytamoxifen (4‐OHT, active metabolite of tamoxifen), and raloxifene (RAL). In‐vitro results indicated that compounds 9 , 10 , 12 , and 13 were more potent than TAM against the human breast cancer cell lines with IC₅₀ < 20 µM. The in‐silico structure–activity relationships of these compounds and their binding mode within the estrogen receptor (ER) binding site using AutoDock vina are discussed.     

Synthesis and Biological Evaluation of Novel 6‐Hydrazinyl‐2,4‐bismorpholino pyrimidine and 1,3,5‐Triazine Derivatives as Potential Antitumor Agents

A series of 6‐hydrazinyl‐2,4‐bismorpholino pyrimidine and 1,3,5‐triazine derivatives ( 5a – 5l and 8a – 8o ) were synthesized and their chemical structures as well as the relative stereochemistry were confirmed. All the synthesized compounds were evaluated for antiproliferative activity against three cancer cell lines (H460, HT‐29, and MDA‐MB‐231). Several potent compounds were further evaluated against two other cell lines (U87MG, H1975). Most of the prepared compounds, particularly compounds 5c and 5j with IC₅₀ values (0.07 and 0.05 µM, respectively) in the nM range, exhibited moderate to excellent antiproliferative activity and high selectivity against the H460 cancer cell line as compared with compound 1 . The most promising compound 5j , possessing a cyano group at the 3‐position of the benzene ring, showed strong antiproliferative activity against H460, HT‐29, and MDA‐MB‐231 cell lines with IC₅₀ values of 0.05, 6.31, and 6.50 µM, which were 4.6‐ to 190.4‐fold more active than compound 1 (9.52, 29.24, and 36.21 µM), respectively.     

Novel quinazolin‐4(3H)‐one linked to 1,2,3‐triazoles: Synthesis and anticancer activity

In this work, a wide range of novel quinazolin‐4(3H)‐one linked to 1,2,3‐triazoles was designed, synthesized, and evaluated against a panel of three human breast (MDA‐MB‐231, MCF‐7, T‐47D), lung (A549), and prostate (PC3) cancer cell lines. Our results revealed that the anticancer activity of the synthesized compounds was selectively affected by the presence of methoxy group on the linker between quinazolinone and 1,2,3‐triazole moieties. According to the calculated IC₅₀ values, compounds 6q , 6w , and 6x showed good cytotoxicity against breast cancer cell lines even more effective than the reference drug, etoposide. Compounds 6q and 6u were found to be potent compounds against A549, non‐small‐cell lung cancer (NSCLC), comparing with erlotinib. Also, the morphological analysis by acridine orange/ethidium bromide double staining test and flow cytometry analysis indicated that potent compounds induced apoptosis in human cancer cell lines. Molecular docking studies were performed to clarify the inhibition mode of compounds 6g , 6u , 6w , and 6x over the EGFR active site. The most promising compounds, 6q and 6u , possessing 3‐methoxy group were well oriented to the gatekeeper hydrophobic pocket of EGFR active site and interact well with Ala719, Val702, and Leu820 through hydrophobic interaction.     

Synthesis and Antiproliferative Activitiy of Novel Diaryl Ureas Possessing a 4H‐Pyrido[1,2‐a]pyrimidin‐4‐one Group

We herein disclose a series of novel diaryl urea derivatives possessing a 4H‐pyrido[1,2‐a]pyrimidin‐4‐one group as novel potent anticancer compounds. The structures were confirmed by IR, ¹H‐NMR, and MS. All the compounds were screened for their antiprofilerative activity agaist the human breast cancer cell line (MDA‐MB‐231). The pharmacological results indicated that most of the compounds showed moderate activity. The best of this series is compound 4c (IC₅₀ = 0.7 μmol/L), with a potency 3.6‐fold higher than Sorafenib (IC₅₀ = 2.5 μmol/L), which was approved in 2005.