Synthesis and antitumoral activity of novel thiazolobenzotriazole, thiazoloindolo[3,2-c]quinoline and quinolinoquinoline derivatives

Design, synthesis, HER2 inhibition and anticancer evaluation of new substituted 1,5-dihydro-4,1-benzoxazepines

A series of 11 new substituted 1,5-dihydro-4,1-benzoxazepine derivatives was synthesised to study the influence of the methyl group in the 1-(benzenesulphonyl) moiety, the replacement of the purine by the benzotriazole bioisosteric analogue, and the introduction of a bulky substituent at position 6 of the purine, on the biological effects. Their inhibition against isolated HER2 was studied and the structure–activity relationships have been confirmed by molecular modelling studies. The most potent compound against isolated HER2 is 9a with an IC₅₀ of 7.31 µM. We have investigated the effects of the target compounds on cell proliferation. The most active compound (7c) against all the tumour cell lines studied (IC₅₀ 0.42–0.86 µM) does not produce any modification in the expression of pro-caspase 3, but increases the caspase 1 expression, and promotes pyroptosis.

Synthesis of hybrids thiazole–quinoline, thiazole–indole and their analogs: in vitro anti-proliferative effects on cancer cell lines, DNA binding properties and molecular modeling

A quinoline–thiazole hybrid was synthesized, which showed cytotoxicity against the HL-60 cell line. Electrochemical and spectroscopic experiments suggested DNA as the biological target.

Experimental spectral characterization, Hirshfeld surface analysis, DFT/TD-DFT calculations and docking studies of (2Z,5Z)-5-(4-nitrobenzylidene)-3-N(2-methoxyphenyl)-2-N'(2-methoxyphenylimino) thiazolidin-4-one

We reported an experimental and theoretical spectroscopic studies of (2Z,5Z)-5-(4-nitrobenzylidene)-3-N (2-methoxyphenyl)-2-N' (2-methoxyphenylimino) thiazolidin-4-one (C24H19N3O5S) molecule, using FT-IR, NMR spectroscopy, and density functional theory (DFT) via time-dependent schema (TD-DFT) respectively. The molecular inter-contacts were explored using Hirshfeld surfaces (HS) analysis method. Vibrational frequencies, gauge-independent atomic orbital (GIAO)1H and13C NMR chemical shift values and frontier molecular orbitals (FMOs) have been calculated from the optimized structure of the molecule by DFT/B3LYP functional with 6-31G(d, p) basis set. Our theoretical results show a good agreement with the experimental data. The calculated UV-visible spectrum employing TD-DFT shows electronic transitions at 388 nm and 495 nm. To get insight on the charge interaction happening inside the molecule, HOMO and LUMO were scrutinized and their calculated energy gap was found to be 2.96 eV. The molecular docking was analyzed via interplay study ofacetyl cholinesterase, and Butyrylcholinesterase using molecular docking methodology.

Thiazole-containing compounds as therapeutic targets for cancer therapy

In the last few decades, considerable progress has been made in anticancer agents development, and several new anticancer agents of natural and synthetic origin have been produced. Among heterocyclic compounds, thiazole, a 5-membered unique heterocyclic motif containing sulphur and nitrogen atoms, serves as an essential core scaffold in several medicinally important compounds. Thiazole nucleus is a fundamental part of some clinically applied anticancer drugs, such as dasatinib, dabrafenib, ixabepilone, patellamide A, and epothilone. Recently, thiazole-containing compounds have been successfully developed as possible inhibitors of several biological targets, including enzyme-linked receptor(s) located on the cell membrane, (i.e., polymerase inhibitors) and the cell cycle (i.e., microtubular inhibitors). Moreover, these compounds have been proven to exhibit high effectiveness, potent anticancer activity, and less toxicity. This review presents current research on thiazoles and elucidates their biological importance in anticancer drug discovery. The findings may aid researchers in the rational design of more potent and bio-target specific anticancer drug molecules.

Identification of dehydroxy isoquine and isotebuquine as promising anticancer agents targeting K+ channel

Traditional antimalarial drugs based on 4-aminoquinolines have exhibited good antiproliferative activities against human tumor cells; however, their low relative efficacy has limited their corresponding clinical uses. In order to identify new potent anticancer agents based on 4-aminoquinoline, we evaluated the antiproliferative activity of a series of dehydroxy isoquines and isotebuquines against five human cancer lines. HeLa and SKBr3 were significantly more sensitive to the action of tested quinolines than the A549, MCF-7, and PC-3 cancer lines. Compound 2h was by far the most potent derivative against four of the tested lines (except to PC3 line), exhibiting low micromolar or nanomolar IC₅₀ values superior to adriamycin reference, low toxicities on dermis human fibroblasts (LD₅₀  > 250 μM), and excellent selectivity indexes against the mentioned cancer cells. A structure-activity relationship analysis put in evidence that a pyrrolidine or morpholine moiety as N-alkyl terminal substitution and the incorporation of the extra phenyl attached to aniline ring are pharmacophore essentials for improvement the anticancer activity of the studied dehydroxy isoquines and isotebuquines. From the results, compound 2h emerged as a promising anticancer candidate for further in vitro assays against resistant-strain and in vivo studies as well as pharmacokinetic and genotoxicity studies. Mechanistic assays suggested that the most active quinoline 2h act as calcium-activated potassium channel activator.

Small molecule PZL318: forming fluorescent nanoparticles capable of tracing their interactions with cancer cells and activated platelets, slowing tumor growth and inhibiting thrombosis

Low selectivity of chemotherapy correlates with poor outcomes of cancer patients. To improve this issue, a novel agent, N-(1-[3-methoxycarbonyl-4-hydroxyphenyl]-β-carboline-3-carbonyl)-Trp-Lys-OBzl (PZL318), was reported here. The transmission electron microscopy, scanning electron microscopy, and atomic force microscopy images demonstrated that PZL318 can form nanoparticles. Fluorescent and confocal images visualized that PZL318 formed fluorescent nanoparticles capable of targeting cancer cells and tracing their interactions with cancer cells. In vitro, 40 μM of PZL318 inhibited the proliferation of tumorigenic cells, but not nontumorigenic cells. In vivo, 10 nmol/kg of PZL318 slowed the tumor growth of S180 mice and alleviated the thrombosis of ferric chloride-treated ICR mice, while 100 μmol/kg of PZL318 did not injure healthy mice and they exhibited no liver toxicity. By analyzing Fourier transform–mass spectrometry and rotating-frame Overhauser spectroscopy (ROESY) two-dimensional nuclear magnetic resonance spectra, the chemical mechanism of PZL318-forming trimers and nanoparticles was explored. By using mesoscale simulation, a nanoparticle of 3.01 nm in diameter was predicted containing 13 trimers. Scavenging free radicals, downregulating sP-selectin expression and intercalating toward DNA were correlated with the antitumor mechanism of PZL318.

Benzotriazole: An overview on its versatile biological behavior

Discovered in late 1960, azoles are heterocyclic compounds class which constitute the largest group of available antifungal drugs. Particularly, the imidazole ring is the chemical component that confers activity to azoles. Triazoles are obtained by a slight modification of this ring and similar or improved activities as well as less adverse effects are reported for triazole derivatives. Consequently, it is not surprising that benzimidazole/benzotriazole derivatives have been found to be biologically active. Since benzimidazole has been widely investigated, this review is focused on defining the place of benzotriazole derivatives in biomedical research, highlighting their versatile biological properties, the mode of action and Structure Activity Relationship (SAR) studies for a variety of antimicrobial, antiparasitic, and even antitumor, choleretic, cholesterol-lowering agents.

A novel protocol for the facile construction of tetrahydroquinoline fused tricyclic frameworks via an intramolecular 1,3-dipolar nitrile oxide cycloaddition reaction

An efficient method towards the synthesis of quinoline fused tricyclic compounds involving an intramolecular 1,3-dipolar nitrile oxide cycloaddition reaction utilizing Baylis–Hillman derivatives in good yields has been described for the first time.

Efficient synthesis of α- and δ-carbolines by sequential Pd-catalyzed site-selective C–C and twofold C–N coupling reactions

Two concise and efficient approaches were developed for the synthesis of α- and δ-carboline derivatives.

Facile “on water” domino reactions for the expedient synthesis of 2H-thiopyrano[2,3-b]quinolines

A facile synthesis of novel 3-nitro-2-aryl-2H-thiopyrano[2,3-b]quinolines from the domino reactions of 2-mercaptoquinoline-3-carbaldehyde and substituted β-nitrostyrenes in the presence of triethylamine (TEA) in water is described.

BPIC: A novel anti-tumor lead capable of inhibiting inflammation and scavenging free radicals

Inflammation has a critical role in the tumor progression, free radical damage can worse the status of patients in cancer condition. The anti-cancer agents capable of inhibiting inflammation and scavenging free radicals attract a lot of our interest. Aimed at the discovery of such anti-tumor agent, a novel intercalator, benzyl 1-[4-hydroxy-3-(methoxycarbonyl)-phenyl-9H-pyrido[3,4-b]indole-3-carboxylate (BPIC) was presented. The docking investigation of BPIC and doxorubicin towards the DNA (PDB ID: 1NAB) gave equal score and similar feature. The anti-proliferation assay of 8 cancer cells identified S180 cells had equal sensitivity to BPIC and doxorubicin. The anti-tumor assay defined the efficacy of BPIC been 2 folds higher than that of doxorubicin. At 1μmol/kg of dose BPIC effectively inhibited xylene-induced ear edema and decreased the plasma TNF-α and IL-8 of the mice. BPIC scavenged ∙OH, ∙O2(-) and NO free radicals in a concentration dependent manner and NO free radicals had the highest sensitivity. BPIC could be a novel anti-tumor lead capable of simultaneously inhibiting inflammation and scavenging free radicals.

Design, synthesis, and biological evaluation of artemisinin-indoloquinoline hybrids as potent antiproliferative agents

A series of artemisinin-indoloquinoline hybrids were designed and synthesized in an attempt to develop potent and selective anti-tumor agents. Compounds 7a–7f, 8 and 9 were prepared and characterized. Their antiproliferative activities against MV4-11, HCT-116, A549, and BALB/3T3 cell lines in vitro were tested. Nearly all of the tested compounds (7–9, except for compounds 7d and 7e against HCT-116) showed an increased antitumor activity against HCT-116 and A549 cell lines when compared to the dihydroartemisinin control. Especially for the artemisinin-indoloquinoline hybrid 8, with an 11-aminopropylamino-10H-indolo[3,2-b]quinoline substituent, the antiproliferative activity against the A549 cell line had improved more than ten times. The IC₅₀ value of hybrid 8 against A549 cell lines was decreased to 1.328 ± 0.586 μM, while dihydroartemisin showed IC₅₀ value of >20 µM in the same cell line. Thus, these results have proven that the strategy of introducing a planar basic fused aromatic moiety, such as the indoloquinoline skeleton, could improve the antiproliferative activity and selectivity towards cancer cell lines.

A review on anticancer potential of bioactive heterocycle quinoline

The advent of Camptothecin added a new dimension in the field anticancer drug development containing quinoline motif. Quinoline scaffold plays an important role in anticancer drug development as their derivatives have shown excellent results through different mechanism of action such as growth inhibitors by cell cycle arrest, apoptosis, inhibition of angiogenesis, disruption of cell migration, and modulation of nuclear receptor responsiveness. The anti-cancer potential of several of these derivatives have been demonstrated on various cancer cell lines. In this review we have compiled and discussed specifically the anticancer potential of quinoline derivatives, which could provide a low-height flying bird's eye view of the quinoline derived compounds to a medicinal chemist for a comprehensive and target oriented information for development of clinically viable anticancer drugs.

Synthesis of 8-hydroxyquinoline derivatives as novel antitumor agents

This letter describes the preparation of quinoline derivatives and their cytotoxic potentials toward human carcinoma cell lines. Among the selected compounds, 8-hydroxy-2-quinolinecarbaldehyde (3) showed the best in vitro cytotoxicity against the human cancer cell lines, including MDA231, T-47D, Hs578t, SaoS2, K562, SKHep1 (with a MTS50 range of 12.5-25 μg/mL) and Hep3B (with a MTS50 range of 6.25±0.034 μg/mL). The in vivo antitumor activity of compound 3 on subcutenaous Hep3B hepatocellular carcinoma xenograft in athymic nude mice was then studied. The results showed that the dose of 10 mg/kg/day of compound 3 with intraperitoneal injection for 9 days totally abolished the growth of the xenograft tumor of Hep3B with no histological damage on vital organs as compared with the control. The experimental results suggested that compound 3 has a good potential as an antitumor agent.

Benzyl 1,2,3,5,11,11a-hexahydro-3,3-dimethyl-1-oxo-6H-imidazo[3',4':1,2]pyridin[3,4-b]indole-2-substituted acetates: One-pot-preparation, anti-tumor activity, docking toward DNA and 3D QSAR analysis

To discover the anti-tumoral indoles a series of benzyl 1,2,3,5,11,11a-hexahydro-3,3-dimethyl-1-oxo-6H-imidazo[3',4':1,2]pyridin[3,4-b]indole-2-substituted acetates (2a-n) are prepared via one-pot-preparation. The IC(50) values of 2a-n in vitro against human lung carcinoma, prostate cancer, nasopharyngeal carcinoma, vincristine-resistant KB subline and human breast carcinoma cells range from 40 nM to 60 microM. On Sarcoma 180 (S180) tumor-bearing mouse model four of them (2e,g,h,i) significantly inhibited the tumor growth. At the dose of 0.1mg/kg the efficacy of the most potent 2h was equal to that of 1.0mg/kg of doxorubicin. In contrast to doxorubicin, at 1.0mg/kg of dose 2e,g,h,i did not induce the treated S180 mice to have organ atrophy and body emaciation. The healthy mice receiving 10, 100 and 500 mg/kg of 2e,g,h,i gave no any neurotoxic response. Even up to the dose of 500 mg/kg the healthy mice occurred no death. The interaction of 2a-n with DNA was confirmed by the fluorescence quenching experiments and automated flexible ligand docking. By 3D QSAR analysis the IC(50) values of 2a-n against prostate cancer cells were correlated with the structures and conformations of their side chains. To increase the data related to their physical-chemical properties the experimental LogP values were also provided.