Structure-activity relationships studies of the anti-angiogenic activities of linomide

Novel Multi-Target Agents Based on the Privileged Structure of 4-Hydroxy-2-quinolinone

In this work, the privileged scaffold of 4-hydroxy-2quinolinone is investigated through the synthesis of carboxamides and hybrid derivatives, as well as through their bioactivity evaluation, focusing on the ability of the molecules to inhibit the soybean LOX, as an indication of their anti-inflammatory activity. Twenty-one quinolinone carboxamides, seven novel hybrid compounds consisting of the quinolinone moiety and selected cinnamic or benzoic acid derivatives, as well as three reverse amides are synthesized and classified as multi-target agents according to their LOX inhibitory and antioxidant activity. Among all the synthesized analogues, quinolinone-carboxamide compounds 3h and 3s, which are introduced for the first time in the literature, exhibited the best LOX inhibitory activity (IC50 = 10 μM). Furthermore, carboxamide 3g and quinolinone hybrid with acetylated ferulic acid 11e emerged as multi-target agents, revealing combined antioxidant and LOX inhibitory activity (3g: IC50 = 27.5 μM for LOX inhibition, 100% inhibition of lipid peroxidation, 67.7% ability to scavenge hydroxyl radicals and 72.4% in the ABTS radical cation decolorization assay; 11e: IC50 = 52 μM for LOX inhibition and 97% inhibition of lipid peroxidation). The in silico docking results revealed that the synthetic carboxamide analogues 3h and 3s and NDGA (the reference compound) bind at the same alternative binding site in a similar binding mode.

Design, synthesis, graph theoretical analysis and molecular modelling studies of novel substituted quinoline analogues as promising anti-breast cancer agents

The most promising class of heterocyclic compounds in medicinal chemistry are those with the quinolin-2-one nucleus. It is a versatile heterocyclic molecule that has been put together with numerous pharmaceutical substances and is crucial in the creation of anticancer medications. In this view, the present research work deals with design, synthesis, and characterization of various analogous of quinolin-2-one nucleus and evaluation of their anticancer activity against MCF-7 cells (adenoma breast cancer cell line). Fourteen new compounds have been synthesised using suitable synthetic route and are characterized by FTIR, 1H NMR, 13C NMR and Mass spectral data. Molecular docking studies of the title compounds were carried out using PyRx 0.8 tool in AutoDock Vina program. All the synthesised compounds were exhibited well conserved hydrogen bonding with one or more amino acid residues in the active pocket of EGFR tyrosine kinase (PDB ID: 1m17). The docking score of the derivatives ranged from - 6.7 to - 9.5 kcal mol-1, standard drug Imatinib with - 9.6 kcal mol-1 and standard active ligand 4-anilinoquinazoline with - 7.7 kcal mol-1. The designed compound IV-A1 showed least binding energy (- 9.5 kcal mol-1) against EGFR tyrosine kinase receptor. Further, top scored compound, IV-A1 found to be most significant against MCF-7 cells with IC50 value of 0.0870 µM mL-1, TGI of 0.0958 µM mL-1, GI50 of 0.00499 µM mL-1, LC50 of 1.670 µM mL-1.

Lossen rearrangement by Rh(III)-catalyzed C-H activation/annulation of aryl hydroxamates with alkynes: access to quinolone-containing amino acid derivatives

A convenient and robust method for the preparation of new CF₃-containing 2-quinolones has been developed via a Rh(III)-catalyzed C-H activation/Lossen rearrangement/annulation cascade of N-pivaloyloxy-arylamides with internal alkynes bearing an α-CF₃-α-amino acid moiety on the triple bond. This work expands the scope of valuable products that are available through C-H activation/annulation reactions of arylamides in organic synthesis.

Design, Synthesis, and Characterization of Novel Linomide Analogues and their Evaluation for Anticancer Activity

BACKGROUND

According to WHO, in 2017, about 90.5 million people suffered from cancer and about 8.8 million deaths occurred due to disease. Although the chemotherapeutic agents have decreased the mortality among the cancer patients but high toxicity and non-specific targets are still major drawbacks. Many researchers have identified linomide, a 4-hydroxy-2-quinolone derivative, as a lead molecule for the development of anticancer agents. With this background, we thought of the following objective.

OBJECTIVE

The objective of this research work involves the synthesis of a series of N-(2-(4- hydroxy-2-oxo-1-phenyl-1,2-dihydroquinolin-3-yl)-2-oxoethyl)-N-alkyl substituted benzene sulfonamides IVa-d (1-3) by replacing the anilide moiety at the third position of linomide with sulfamoylacyl and also N-methyl by N-phenyl functionality. To perform in silico anticancer activity by using Molegro Virtual Docker (MVD-2013, 6.0) software and in vitro anticancer activity by MTT assay.

METHODS

The starting material 4-hydroxy-1-phenylquinolin-2(1H)-one was treated with N-bromosuccinamide to yield compound II. Condensation of compound II with primary amines resulted in compounds IIIa-d, which, on coupling with substituted aromatic sulfonyl chlorides yield the title compounds IVa-d (1-3).

RESULTS

All the synthesized compounds were satisfactorily characterized by spectral data. The results of docking revealed that the synthesized compounds exhibited well-conserved hydrogen bonds with one or more amino acid residues in the active pocket of EGFRK tyrosine kinase domain (PDB ID: 1m17). The MolDock Score of compound IVd-1 (-115.503) was the highest amongst those tested. The in vitro anticancer activity results showed that compound IVc-1 (R= - (CH2) 2-CH3 ; R'= -H) and IV d-1 (R= -CH2-C6H5; R'= -H) were found to be most potent against K562 cell line with an IC50 of 0.451 μM/ml and 0.455 μM/ml respectively. Compound IVd-1 also showed better potency against A549 cell line with IC50 value of 0.704 μM/ml.

CONCLUSION

The results of in silico and in vitro anticancer activity are in agreement with each other. Compound IV d-1 was found to be most active of the series.

One-pot copper-catalyzed three-component reaction: a modular approach to functionalized 2-quinolones

A copper-catalyzed three-component annulation for the synthesis of functionalized 2-quinolones was developed. Three reactions including an S_N2, a Knoevenagel, and finally C–N bond formation are involved in the designed cascade reaction using 2-bromoacylarenes, 2-iodoacetamide, and nucleophiles as the three components. A new catalytic system was discovered during the study and this modular approach is highly efficient to access functionalized 2-quinolone derivatives, compatible with a broad range of functional groups, scalable, and step-economic. Further derivatization of the obtained product demonstrates the synthetic utility of this method.

A copper-catalyzed three-component annulation for the synthesis of functionalized 2-quinolones was developed.

Transition-metal free direct C–H functionalization of quinoxalin-2(1H)-ones with oxamic acids leading to 3-carbamoyl quinoxalin-2(1H)-ones

A practical transition-metal free decarboxylative coupling reaction of oxamic acids with quinoxalin-2(1H)-ones has been developed under mild conditions.

Step-economical synthesis of 3-amido-2-quinolones by dendritic copper powder-mediated one-pot reaction

The one-pot protocol by the dendritic copper powder-mediated Knoevenagel condensation/annelation is delineated here for the synthesis of 3-amido-2-quinolones. It is practical with moisture tolerance and easy setup, and is compatible with many functional groups under mild conditions. This method was applied for the preparation of the key intermediates of biologically relevant 3-amido-2-quinolones.

One-Pot Three-Component Synthesis of Novel Diethyl((2-oxo-1,2-dihydroquinolin-3-yl)(arylamino)methyl)phosphonate as Potential Anticancer Agents

With the aim of discovering new anticancer agents, we have designed and synthesized novel α-aminophosphonate derivatives containing a 2-oxoquinoline structure using a convenient one-pot three-component method. The newly synthesized compounds were evaluated for antitumor activities against the A549 (human lung adenocarcinoma cell), HeLa (human cervical carcinoma cell), MCF-7 (human breast cancer cell), and U2OS (human osteosarcoma cell) cancer cell lines in vitro, employing a standard 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The results of pharmacological screening indicated that many compounds exhibited moderate to high levels of antitumor activities against the tested cancer cell lines and that most compounds showed more potent inhibitory activities comparable to 5-fluorouracil (5-FU) which was used as a positive control. The mechanism of representative compound 4u (diethyl((2-oxo-1,2-dihydroquinolin-3-yl)(phenyl-amino)methyl)phosphonate) indicated that the compound mainly arrested HeLa cells in S and G2 stages and was accompanied by apoptosis in HeLa cells. This action was confirmed by acridine orange/ethidium bromide staining, Hoechst 33342 staining, and flow cytometry.

N-Phenyl-4-hydroxy-2-quinolone-3-carboxamides as selective inhibitors of mutant H1047R phosphoinositide-3-kinase (PI3Kα)

This work describes our efforts to optimize the lead PI3Kα inhibitor N-benzyl 4-hydroxy-2-quinolone-3-carboxamide using structure-based design and molecular docking. We identified a series of N-phenyl 4-hydroxy-2-quinolone-3-carboxamides as selective inhibitors of mutant H1047R versus wild-type PI3Kα and we also showed that the cell growth inhibition by these compounds likely occurs by inhibiting the formation of pAKT and induction of apoptosis.

Investigation of the potential utility of a linomide analogue for treatment of choroidal neovascularization

The aim of this study was to test the selectivity, in-vivo effectiveness, and potential mechanism of action of a linomide analogue (N-phenyl-1,2-dihydro-4-hydroxyl-2-oxo-quinoline-3-carboxamide, Lin05) for inhibition of choroidal neovascularization. The selectivity of Lin05 was tested in cell proliferation assays with human umbilical vein endothelial cells (HUVEC) and a retinal pigmented epithelial cell line(ARPE-19). In-vivo anti-angiogenic effect of Lin05 was investigated utilizing an experimental laser-induced choroidal neovascularization (ECNV) model in adult Brown Norway rats. Western blot and/or reverse transcriptase-PCR was used to test the effect of Lin05 on potential targets. Our results indicate that Lin05 is at least an 8-fold more selective inhibitor of endothelial cell proliferation compared to RPE cells. Systemic administration of Lin05 in an ECNV model was associated with a significant decrease in both vascular leakage on fluorescein angiography and lesion size by histopathology (p = 0.02). No systemic toxicity was detected for Lin05 in major organs such as the liver, lung and kidneys. Lin05 did not inhibit VEGF-induced VEGFR2 (KDR) phosphorylation in HUVEC nor was associated with decreased VEGF gene expression. Also it did not inhibit insulin-like growth factor (IGF-1) and Epidermal Growth Factor (EGF) induced activation of p42/p44 MAPK activation. It inhibited both PDGF- and bFGF-induced p42/p44 MAPK phosphorylation. However, the effect on PDGF was variable in different HUVEC cells. In conclusion, Lin05 is a potential anti-angiogenic agent for the treatment of eye diseases associated with pathological neovascularization. The anti-angiogenic effect of Lin05 is likely through inhibition of bFGF but not through inhibition of the VEGF/KDR pathway.

A new synthetic approach to functionalize pyrimido[4,5-b]quinoline-2,4(1H,3H)-diones via a three-component one-pot reaction

Functionalized pyrimido[4,5-b]quinoline-2,4 (1H,3H)-diones were synthesized by a three-component one-pot reaction involving barbituric acid, aldehydes, and anilines. The use of commercially available anilines allowed the facile syntheses of pyrimido[4,5-b]quinolinediones substituted in all the positions on the benzene ring with electron donor or electron withdrawing groups. This straightforward method circumvents the preparation of unstable substituted 2-aminobenzaldehydes that limits the scope of previously described syntheses. Furthermore, access to the 5-substituted derivatives is now also possible starting from aliphatic or aromatic aldehydes. Our strategy and methodology offer significant and practical improvements over other methodologies.

Role of HIF signaling on tumorigenesis in response to chronic low-dose arsenic administration

Trivalent inorganic arsenic (arsenite, arsenic trioxide, As(III)) is a primary contaminant of groundwater supplies worldwide. As(III), marketed as trisenox, is also an FDA-approved agent to treat cancer It has been previously shown by our laboratory that As(III) administered at doses lower than a therapeutic anticancer dose results in an increase in tumor formation and blood vessel density of tumors. In this work it was found that chronic administration of As(III) approaching the EPA action level of 10 ppb, given in the drinking water of mice 5 weeks prior to B16-F10 melanoma implantation, increased the growth rate of primary tumors and the number of metastases to the lung. Further, levels of arsenic in the tumor and lung were found to be much greater than those in the blood and similar to pro-angiogenic As(III) doses. Levels of hypoxia inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) surrounding the blood vessels in the tumors of the As(III)-treated mice were also found to be increased. Exposure of isolated B16-F10 tumor cells to chronic (3 or 7 day) but not acute (4 h) low-dose As(III) was found to increase HIF-1alpha expression and secretion of VEGF. Finally, coadministration of an inhibitor of HIF (YC-1) or a VEGFR-2 kinase inhibitor (SU5416) was found to antagonize the pro-angiogenic effects of low-dose As(III). Together, these results suggest that chronic exposure to low-dose As(III) could stimulate growth of tumors through a HIF-dependent stimulation of angiogenesis.