Synthesis and anticancer activity of para-xylyl linked bis-benzimidazolium salts and respective Ag(I) N-heterocyclic carbene complexes

The article describes synthesis, characterization (NMR, FT-IR, microanalysis, X-ray crystallography), and in vitro anticancer activity of para-xylyl linked bis-benzimidazolium salts and respective dinuclear Ag–NHC complexes. All the compounds were tested for their cytotoxicity against human colorectal cancer (HCT 116) and promyelocytic leukemia (HL-60) cell lines. According to cell viability measurements using MTT assay, all tested compounds showed dose-dependent cytotoxic activity against both cell lines. The tested compounds demonstrated significant activity with IC₅₀ values range 0.01–18.7 μM for HCT 116 and 0.7–55.7 μM for HL-60 cells. 5-Fluorouracil was used as standard drug (IC₅₀ 19.2 μM for HCT 116 and 5.4 μM for HL-60). We found that as the size of N-alkyl substitution on benzimidazolium salt increases its cytotoxicity decreases whereas a reverse occurred in case of respective complexes.     

Synthesis,cytotoxicity, and molecular docking of substituted 3-(2-methylbenzofuran-3-yl)-5-(phenoxymethyl)-1,2,4-oxadiazoles

A series of new benzofuran/oxadiazole hybrids ( 8a – n ) was synthesized from 2H-chromene-3-carbonitriles ( 3a – c ) through the multistep synthetic methodology, and these hybrids are known to exhibit anticancer activities. All the compounds were evaluated for their in vitro cytotoxicity against the HCT116 and MIA PaCa2 cell lines. Compounds 6a (IC₅₀: 9.71 ± 1.9 μM), 6b (IC₅₀: 7.48 ± 0.6 μM), and 6c (IC₅₀: 3.27 ± 1.1 μM) displayed a significant cytotoxic activity, whereas compounds 8d and 8e exhibited good activity against both cell lines. The depletion of glycogen synthase kinase-3β (GSK3β) induces apoptosis through the inhibition of basal NF-κB activity in HCT116 colon cancer cells and MIA PaCa2 pancreatic cancer cells. Molecular docking of compounds 6a , 6b , 6c , 8d , and 8e with GSK3β demonstrated the best binding affinity, correlating with the biological activity assay. Furthermore, the structure–activity relationship of these novel compounds reveals promising features for their use in anticancer therapy.     

Antilipase and antiproliferative activities of novel fluoroquinolones and triazolofluoroquinolones

Fluoroquinolones (FQs) have been identified recently as potent inhibitors of pancreatic lipase (PL). The aim of this study was to synthesize novel FQs and triazolofluoroquinolones (TFQs) and to evaluate them in vitro with respect to their antilipolytic efficacy and potency properties. The PL‐IC₅₀ values of 12 FQs and TFQs ( 3 ( a–c ) –6 ( a–c )) were in the range of 12.5–189.1 μm . These values are further supported by docking studies. The suggested association between obesity and colorectal cancer initiated the evaluation of antiproliferative activity of the new FQs and TFQs against a panel of obesity‐related colorectal cells (HT29, HCT116, SW620 CACO2, and SW480). Sulforodamine B colorimetric assay revealed that some derivatives exhibited unselective cytotoxicity against HT29, HCT116, SW620 CACO2, and SW480. Remarkably, FQ 4a 's selective cytotoxicity against HCT116 was found valuable with IC₅₀ value of 4.2 μm which exceeds that of cisplatin with a substantial selective cytotoxicity in periodontal ligament fibroblasts. In conclusion, FQ and TFQ derivatives may unveil new antiobesity and anticancer agents in the future.     

5-(4-Methoxybenzylidene)thiazolidine-2,4-dione-derived VEGFR-2 inhibitors: Design,synthesis, molecular docking,and anticancer evaluations

A novel series of 5-(4-methoxybenzylidene)thiazolidine-2,4-dione derivatives, 5a–g and 7a–f , was designed, synthesized, and evaluated for their anticancer activity against HepG2, HCT116, and MCF-7 cells. HepG2 and HCT116 were the most sensitive cell lines to the influence of the new derivatives. In particular, compounds 7f , 7e , 7d , and 7c were found to be the most potent derivatives of all the tested compounds against the HepG2, HCT116, and MCF-7 cancer cell lines. Compound 7f (IC₅₀ = 6.19 ± 0.5, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively) exhibited a higher activity than sorafenib (IC₅₀ = 9.18 ± 0.6, 8.37 ± 0.7, and 5.10 ± 0.4 µM, respectively) against HepG2 and MCF-7, cells but a lower activity against HCT116 cancer cells, respectively. Also, this compound displayed a higher activity than doxorubicin (IC₅₀ = 7.94 ± 0.6, 8.07 ± 0.8, and 6.75 ± 0.4 µM, respectively) against HepG2 and MCF-7 cells, but nearly the same activity against HCT116 cells, respectively. All derivatives, 5a–g and 7a–f , were evaluated for their inhibitory activities against vascular endothelial growth factor receptor-2 (VEGFR-2). Among them, compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.12 ± 0.02 µM, which is nearly the same as that of sorafenib (IC₅₀ = 0.10 ± 0.02 µM). Compounds 7e , 7d , 7c , and 7b exhibited the highest activity, with IC₅₀ values of 0.13 ± 0.02, 0.14 ± 0.02, 0.14 ± 0.02, and 0.18 ± 0.03 µM, respectively, which are more than the half of that of sorafenib. Furthermore, molecular docking was performed to investigate their binding mode and affinities toward the VEGFR-2 receptor. The data obtained from the docking studies highly correlated with those obtained from the biological screening.     

Synthesis and preliminary evaluation activity studies of novel 4-(aryl/heteroaryl-2-ylmethyl)-6-phenyl-2-[3-(4-substituted-piperazine-1-yl)propyl]pyridazin-3(2H)-one derivatives as anticancer agents

A series of new 4-(aryl/heteroaryl-2-ylmethyl)-6-phenyl-2-[3-(4-substituted piperazine-1-yl)propyl] pyridazin-3(2H)-one derivatives were synthesized. The structures of the compounds were confirmed by IR, ¹H NMR, and mass spectral data. All the compounds were evaluated for their cytotoxicity toward five human cancer cell lines of different origins viz; HeLa (Cervical), SKBR3 (Breast), HCT116 (Colon), A375 (Skin) & H1299 (Lung) at different concentrations and the IC₅₀ values were determined. HCT116 and HeLa are the most sensitive against the compounds studied. One of them displayed moderate cytotoxicity against SKBR3. Majority of the compounds exhibited good to moderate activity.     

Synthesis and biological evaluation of 1-(3-chloro-2-oxo-4-phenylazetidin-1-yl)-3-(2-oxo-2-(10H-phenothiazin-10-yl)ethyl)urea derivatives

A new series of eleven novel 1-(3-chloro-2-oxo-4-phenylazetidin-1yl)-3-(2-oxo-2-(10H-phenothiazin-10-yl)ethyl)urea derivatives were synthesized by cyclocondensation of various Schiff bases of phenothiazine with chloroacetyl chloride in the presence of triethylamine. Various Schiff bases of phenothiazine were synthesized by condensation of 4-(2-oxo-2-(10H-phenothiazin-10-yl)ethyl semicarbazide with various aryl aldehydes. The synthesized compounds were characterized by IR, MASS and ¹H NMR spectral data and evaluated for in vitro antimicrobial, antitubercular, antioxidant and anticancer activities by disc diffusion method, MIC method, REMA, DPPH, FRAP and MTT assay method, respectively. All synthesized compounds showed moderate-to-significant anti-bacterial and anti-fungal activity and compound 4d, 4g, 4h and 4k showed good antioxidant activity with EC₅₀ value of 55, 57, 56 and 47 μg/ml tested by DPPH method. The compounds 4j at a concentration of 10 μg/ml showed inhibition against the growth of Mycobacterium tuberculosis and 4f showed significant activity against human cervical cancer cell line with IC₅₀ values of 18.26 μM.     

Rational drug design of indazole‐based diarylurea derivatives as anticancer agents

A series of novel indazole‐based diarylurea derivatives targeting c‐kit were designed by structure‐based drug design. The derivatives were prepared, and their antiproliferative activities were evaluated against human colon cancer HCT‐116 cell line and hepatocellular carcinoma PLC/PRF/5 cell line. The antiproliferative activities demonstrated that six of nine compounds exhibited comparable activities with sorafenib against HCT‐116. The structure–activity relationship (SAR) analysis indicated that the indazole ring part tolerated different kinds of substituents, and the N position of the central pyridine ring played key roles in antiproliferative activity. The SAR and interaction mechanisms were further explored using molecular docking method. Compound 1i with N‐(2‐(pyrrolidin‐1‐yl)ethyl)‐carboxamide possessed improved solubility, 596.1 ng/ml and best activities, IC₅₀ at 1.0 μm against HCT‐116, and 3.48 μm against PLC/PRF/5. It is a promising anticancer agent for further development.     

Synthesis,cytotoxic activity,and 2D‐ and 3D‐QSAR studies of 19‐carboxyl‐modified novel isosteviol derivatives as potential anticancer agents

Two series of novel acylthiosemicarbazide and oxadiazole fused‐isosteviol derivatives were synthesized based on the 19‐carboxyl modification. The target compounds were evaluated for their cytotoxicities against three cancer cell lines (HCT‐116, HGC‐27, and JEKO‐1) using an MTT assay. Lead compounds from the acylthiosemicarbazides ( 4 ) showed IC₅₀ values in the lower micromolar range. For example, compounds ( 4i , 4l , 4m , 4r, and 4s ) exhibited significant inhibitory activities against the three cell lines with IC₅₀ values of 0.95–3.36 μm . Furthermore, 2D‐HQSAR and 3D‐topomer CoMFA analyses were established, which could be used to develop second generation of isosteviol derivatives as anticancer agents.     

Design,synthesis and pharmacophoric model building of new 3‐alkoxymethyl/3‐phenyl indole‐2‐carboxamides with potential antiproliferative activity

Novel 3‐alkoxymethyl/3‐phenyl indole‐2‐carboxamide derivatives were synthesized and evaluated for their anticancer activity. Most of the tested compounds showed moderate to excellent activity against the tested cell lines (MCF7 and HCT116). 3‐Phenyl substitution on indole with p‐piperidinyl phenethyl 24a and p‐dimethylamino phenethyl 24c exhibited anticancer activity against MCF7 with IC₅₀ of 0.13 and 0.14 μm , respectively. Further mechanistic study of the most active compounds through their action on cell cycle showed disturbance in cell cycle progression and cell cycle arrest. For future development of this series of compounds, pharmacophore study was conducted which indicated that the enhancement of the activity could be achieved through the addition of acceptor or donating groups to the already‐present indole nucleus.     

Design,Synthesis, and Biological Evaluation of Pyrazole Derivatives

In this in vitro study, a series of novel pyrazole derivatives were designed, synthesized, and evaluated against five human cancer cell lines (PC3, A549, HL60, HCT116, and SW620) for their antiproliferative and p53‐MDM2 binding inhibitory activities. Although biological evaluations showed that this series of compounds possessed weak p53‐MDM2 inhibitory activities, most of them displayed moderate to potent antiproliferative activities against the tested cells lines. Compound 11c exhibited the best potency for MDM2 (FP‐IC₅₀ = 29.22 μm ) and demonstrated antiproliferative activities in response to the five tested cell lines (IC₅₀ = 4.09–16.82 μm ). Compared with the positive control Nutlin‐1, there was enhanced antiproliferative activity to p53‐mutated or p53‐deficient cell lines (SW620, HL60, and PC3).     

Design,synthesis, and cytotoxic evaluation of novel furo[2,3‐b]quinoline derivatives

A number of novel furo[2,3‐b]quinoline derivatives were designed and synthesized by introducing benzyl ether, benzoate, and benzenesulfonate to 6‐position of furo[2,3‐b]quinoline and their chemical structures were confirmed by ESI‐MS, ¹H NMR, and ¹³C NMR spectra. All target compounds were evaluated in vitro against four human cancer cell lines (HCT‐116, MCF‐7, U2OS, and A549) by MTT method. Cytotoxic assay showed that compounds 8a , 8e , 10a , 10b, and 10c exhibited more potent cytotoxicities compared to 2‐bromine‐6‐hydroxy‐furo‐[2,3‐b]quinoline ( 7 ). Compound 10c exhibited higher antiproliferative activity (IC₅₀ values ranging from 4.32 to 24.96 μm ) against four human cancer cell lines (HCT‐116, MCF‐7, U2OS, and A549) and weak cytotoxicity on normal cell HL‐7702, which suggested that 10c might be an ideal anticancer candidate. Compounds 8a , 10a , 10b showed good selectivities to MCF‐7 and HCT‐116, which could be considered as ideal selective candidates for further study. The SARs showed that the introduction of the benzyl ether and benzenesulfonate could significantly improve cytotoxicities, while the benzoate failed to enhance potency obviously.     

Synthesis and in vitro cytotoxicity study of 3-(1H-indol-3-yl)-1,3-diphenylpropan-1-ones

A series of 3-(1H-indol-3-yl)-1,3-diphenylpropan-1-ones 3a–l were synthesized in good to excellent yield by Michael addition of indole 1 with α,β-unsaturated ketones 2a–l in presence of indium(III) sulphate (20 mol%). The structure of the title compounds were established by ¹H NMR, ¹³C NMR, mass and elemental analysis. All the synthesized compounds were evaluated for in vitro cytotoxicity against five different cancer cell lines such as ACHN (human kidney adenocarcinoma), Panc1 (pancreatic), Calu1 (lung), H460 (non small cell lung), HCT116 (human colon cancer cell) and MCF10A (normal breast epithelium) using propidium iodide staining assay protocol. The result showed that the compounds 3e and 3l have excellent cytotoxic activity with the IC₅₀ value ranging from 1.4–2.7 to 2.4–3.4 μM, respectively, in comparison with the other compounds, Flavopiridol and Gemcitabine were employed as a positive control. The findings conferred 3-(1H-indol-3-yl)-1,3-diphenylpropan-1-ones seem to be promising candidates for the development of new anticancer drugs.     

Thiourea and thioether derivatives of sorafenib: synthesis, crystal structure, and antiproliferative activity

A series of novel sorafenib derivatives containing diaryl thiourea and thioether, 9a–u, was designed and synthesized, and their antiproliferative activities against HCT116 and MDA-MB-231 cell lines were also evaluated and described. Most compounds exhibited potent antiproliferative activity against HCT116 cells with IC₅₀ = 1.8–80.4 μM. Compounds 9p, 9r, and 9s demonstrated competitive antiproliferative activities to sorafenib, against all two cancer cell lines. The structures of all the newly synthesized compounds were determined by ¹H NMR, ¹³C NMR, and HRMS, and compound 9n was characterized by single-crystal X-ray diffraction. Primary structure–activity relationships (SAR) have also been established.     

Synthesis, anticancer and antibacterial activities of piperine analogs

A series of piperine analogs were synthesized by the condensation of piperic acid with different aminoacids and substituted aniline. The synthesized compounds (4a–4e) were evaluated for their anticancer activity against human cancer cell lines (MCF-7, Breast Cancer cell line, and Hela cervix cell line) and antibacterial activity against human pathogens (Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Shigella dysenteriae, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa). The efficacies of the synthesized compounds were superior to those of piperine in all tested human cancer cell lines. Among the tested conjugates, 4c showed significant anticancer activity against Hela cervix cell line with IC₅₀ of 0.736 μmol and 4a showed significant activity against breast cancer cell line. The antibacterial activity of the tested compounds was also found to be superior to that of piperine. The approach is novel as the abundantly available natural product piperine is utilized as precursor for the synthesis of new potential antimicrobial and anticancer agents.     

Benzoxazole/benzothiazole‐derived VEGFR‐2 inhibitors: Design,synthesis, molecular docking,and anticancer evaluations

A novel series of benzoxazole/benzothiazole derivatives 4a–c – 11a–e were designed, synthesized, and evaluated for anticancer activity against HepG2, HCT‐116, and MCF‐7 cells. HCT‐116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 4c was found to be the most potent derivative against HepG2, HCT‐116, and MCF‐7 cells, with IC₅₀ values = 9.45 ± 0.8, 5.76 ± 0.4, and 7.36 ± 0.5 µM, respectively. Compounds 4b, 9f , and 9c showed the highest anticancer activities against HepG2 cells with IC₅₀ values of 9.97 ± 0.8, 9.99 ± 0.8, and 11.02 ± 1.0 µM, respectively, HCT‐116 cells with IC₅₀ values of 6.99 ± 0.5, 7.44 ± 0.4, and 8.15 ± 0.8 µM, respectively, and MCF‐7 cells with IC₅₀ values of 7.89 ± 0.7, 8.24 ± 0.7, and 9.32 ± 0.7 µM, respectively, in comparison with sorafenib as reference drug with IC₅₀ values of 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively. The most active compounds 4a–c, 9b,c,e,f,h , and 11c,e were further evaluated for their VEGFR‐2 inhibition. Compounds 4c and 4b potently inhibited VEGFR‐2 at IC₅₀ values of 0.12 ± 0.01 and 0.13 ± 0.02 µM, respectively, which are nearly equipotent to the sorafenib IC₅₀ value (0.10 ± 0.02 µM). Furthermore, molecular docking studies were performed for all synthesized compounds to assess their binding pattern and affinity toward the VEGFR‐2 active site.     

Anticancer,antioxidant and antibiotic activities of mushroom Ramaria flava

Ramaria flava is a species of edible mushroom with some bioactivity. The anticancer, antioxidant and antibiotic activities and chemical composition of R. flava ethanol extract (EE) were evaluated. The present study exhibited that the EE displayed the strongest inhibitory activity against tumor cell MDA-MB-231 with an IC₅₀ value of 66.54 μg/mL in three tested tumor cell lines, and the inhibition percent was 71.66% at the concentration of 200 μg/mL (MTT assay). The total phenolic compounds varied among four fractions of the EE from 6.66 to 61.01 mg gallic acid equivalent (GAE) per g dry weight. Water fraction exhibited high DPPH and OH radical-scavenging activities with low IC₅₀ values of 5.86 and 18.08 μg/mL, respectively. Meanwhile, three phenolic compounds from water fraction were also identified by HPLC. The antibiotic activities of the EE were evaluated against three microorganisms and three fungi strains by means of the agar well diffusion method and the poisoned medium technique, respectively. The EE also showed moderate antibiotic activities. These results suggest that R. flava could hold a good potential source for human health.     

Synthesis and cytotoxic evaluation of novel 2,3-di-O-alkyl derivatives of l-ascorbic acid

A new series of 2,3-di-O-alkyl derivatives of 5,6-O-isopropylidene-l-ascorbic acid were synthesized using phase transfer catalysis in aqueous media. These derivatives were screened for their superoxide radical scavenging activity and anticancer activity against human breast cancer cell line (MCF-7), leukemic cell line (HL-60), and cervical cell line (HeLa). All these derivatives exhibited enhanced scavenging effect than l-ascorbic acid except for the 4-fluorobenzyl or 2/4-chlorobenzyl alkyl group either at 3-O and/or 2-O position displayed pro-oxidant activity. These pro-oxidant derivatives (2c–e, m) exhibited potent anticancer activities against all the cell lines (IC₅₀ = 25.79–57.21 μM). However, these compounds were also cytotoxic to human normal leukemic macrophages THP-1. On the other hand, antioxidant derivatives displayed albeit slight (2k, IC₅₀ = 57.96–63.45 μM), but selective inhibitory effect toward all tumor cell lines. Thus, pro-oxidant and antioxidant properties can be used to predict the cytotoxic selectivity of drug against normal and cancer cells.     

Evaluation of in vitro cytotoxicity of one-dimensional chain [Fe(salen)(L)]n complexes against human cancer cell lines

The 1d-polymeric iron(III) complexes [Fe(salen)(μ-L)]_n (1–6), involving a deprotonated form of the N-donor heterocyclic compounds (L) imidazole (complex 1), 1,2,4-triazole (2), benztriazole (3), 5-methyltetrazole (4), 5-aminotetrazole (5) and 5-phenyltetrazole (6), were studied for their in vitro cytotoxic activity against human cancer cell lines including lung carcinoma (A549), cervix epithelial carcinoma (HeLa), osteosarcoma (HOS), malignant melanoma (G361), breast adenocarcinoma (MCF7), ovarian carcinoma (A2780) and cisplatin-resistant ovarian carcinoma (A2780cis). Cytotoxicity in vitro (IC₅₀ = 0.39–0.48 μM) was achieved for 2–6 against A2780 (IC₅₀ of cisplatin equals 11.5 μM) as well as for 5 and 6 against all the tested cells, with IC₅₀ = 2.5–37.7 μM. The Uv–Vis spectroscopic study showed that the complexes are unstable in organic solvents (e.g. dimethyl sulfoxide, dimethylformamide) containing even trace amounts of water (and thus also in the medium, i.e. 0.1% DMF, v/v, used in the MTT assay), where they partially or completely decompose to the mixtures involving, besides [Fe(salen)(μ-L)]_n itself, also the starting compounds [{Fe(salen)}₂(μ-O)] and appropriate organic compound (HL). In efforts to find how the resulting cytotoxicity of the most active compounds 5 and 6 is influenced by this fact, the in vitro cytotoxicity testing of mixtures of reactants [{Fe(salen)}₂(μ-O)] and HL, as well as the respective reactants, was also performed. It has been found that the cytotoxicity of 5 and 6 against all the tested cell lines is probably caused by a combined effect of the individual components presented within the corresponding mixture in the medium used.     

Synthesis and evaluation of isonicotinoyl hydrazone derivatives as antimycobacterial and anticancer agents

A new series of isonicotinoyl hydrazone derivatives (3a–3o) have been synthesized, characterized and evaluated for in vitro antimycobacterial activity against M. tuberculosis H37Rv and two clinical isolates using tetrazolium microplate assay (TEMA). Some of these compounds showed moderate to good antimycobacterial activity at micro molar concentrations. Among them, 3k and 3m were the most potent analogues with an inhibition concentration at 0.59 and 0.65 μM, respectively, against M. tuberculosis H37Rv compared to parent drug, isoniazid (0.57 μM). Additionally, all the synthesized compounds were subjected to in vitro anticancer activity against human colorectal cancer cell lines (HCT 116). Compounds 3b and 3l displayed antiproliferative activity at inhibitory concentration 3.1 and 0.29 μM, respectively, when compared to standard, 5-fluorouracil (5 μM). These results can be considered as an important start point for the rational design of new leads for antitubercular and anticancer drug discovery.