Design, synthesis and molecular docking study of novel quinoxalin-2(1H)-ones as anti-tumor active agents with inhibition of tyrosine kinase receptor and studying their cyclooxygenase-2 activity

The C3-H Bond Functionalization of Quinoxalin-2(1H)-Ones With Hypervalent Iodine(III) Reagents

The modification of quinoxalin-2(1H)-ones via direct C-H bond functionalization has begun to receive widespread attention, due to quinoxalin-2(1H)-one derivatives' various biological activities and pharmaceutical properties. This mini review concentrates on the accomplishments of arylation, trifluoromethylation, alkylation, and alkoxylation of quinoxalin-2(1H)-ones with hypervalent iodine(III) reagents as reaction partners or oxidants. The reaction conditions and mechanisms are compared and discussed in detail.

Biological and molecular modeling studies on some transition metal(II) complexes of a quinoxaline based ONO donor bishydrazone ligand

In this report, synthesis, characterization, biological and molecular modeling studies of an ONO donor tridentate bishydrazone ligand, 3-[N'-(2-Hydroxy-3-methoxy-benzylidene)-hydrazino]-1H-quinoxalin-2-one (HHQ) and its 1:1 mononuclear Co(II) (HHQ-1), Ni(II) (HHQ-2), Cu(II) (HHQ-3) and Zn(II) (HHQ-4) complexes have been conferred. Octahedral geometry was assigned to HHQ-1, HHQ-2 and HHQ-4 and distorted octahedral geometry for HHQ-3. The lattice parameters, morphology and electrochemical behaviors of the compounds were studied by powder XRD, SEM and cyclic voltammetry analyses respectively. The antimicrobial assays were carried out against the bacterial (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) and fungal (Aspergillus flavus, Aspergillus niger and Candida albicans) strains. Furthermore, the DNA binding, cleaving and superoxide dismutase (SOD) activities of HHQ and its metal(II) complexes were discussed. The structures of HHQ and its derivatives were optimized by DFT techniques. Using molecular docking the molecular interaction dynamics amongst the DNA and SOD with HHQ and its metal(II) complexes were recognized.Communicated by Ramaswamy H. Sarma.

New pyrimidines and triazolopyrimidines as antiproliferative and antioxidants with cyclooxygenase-1/2 inhibitory potential

Aim: Cyclooxygenase-2 (COX-2) inhibition and scavenging-free radicals are important targets in cancer treatment. Materials & methods: Sulfanylpyrimidines and triazolopyrimidines were synthesized and evaluated as anticancer and antioxidant COX-1/2 inhibitors. Results: Compound 7 showed the same growth inhibitory activity as 5-fluorouracil against MCF-7. Compound 6f displayed broad-spectrum anticancer activity against the four tested cancer cell lines. Compounds 5b, 6a, 6c, 6d and 8 were found to be more active antioxidants than trolox. Compounds 6a, 6c, 6f and 8 revealed high COX-2 inhibitory activity and selectivity, which was confirmed by docking studies. Conclusion: Compound 6f could be considered as promising anticancer and antioxidant structural lead with COX-2 inhibition that deserve further derivatization and investigation.

Transition-metal-free direct C-3 cyanation of quinoxalin-2(1H)-ones with ammonium thiocyanate as the “CN” source

A practical protocol for TBHP-mediated oxidative C–H cyanation of quinoxalin-2(1H)-ones utilizing ammonium thiocyanate as the cyanide source has been developed under metal free conditions.

Peroxide-mediated site-specific C–H methylation of imidazo[1,2-a]pyridines and quinoxalin-2(1H)-ones under metal-free conditions

An effective approach to realize the direct methylation of imidazo[1,2-a]pyridines and quinoxalin-2(1H)-ones with peroxides under metal-free conditions is described.

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.

Visible-light-promoted acridine red catalyzed aerobic oxidative decarboxylative acylation of α-oxo-carboxylic acids with quinoxalin-2(1H)-ones

Visible-light-mediated procedure has been developed for the synthesis of 3-acyl quinoxalin-2(1H)-ones through acridine red catalyzed decarboxylative acylation of α-oxo-carboxylic acids with quinoxalin-2(1H)-ones.

tert-Butylhydroperoxide (TBHP) mediated oxidative cross-dehydrogenative coupling of quinoxalin-2(1H)-ones with 4-hydroxycoumarins, 4-hydroxy-6-methyl-2-pyrone and 2-hydroxy-1,4-naphthoquinone under metal-free conditions

We report an efficient and atom-economical method of C-3 functionalization of quinoxalin-2(1H)-ones with 4-hydroxycoumarins, 4-hydroxy-6-methyl-2-pyrone, and 2-hydroxy-1,4-naphthoquinone via the free radical cross-coupling pathway under metal-free conditions. tert-Butylhydroperoxide (TBHP) smoothly promotes the reaction furnishing the cross-dehydrogenative coupling (CDC) products in very good to excellent yields. The protocol neither uses any toxic reagents nor metal catalysts to carry out the reaction, and all the products have been obtained without column chromatography purification. Different radical trapping experiments with 2,2,6,6-tetramethylpiperidine-1-oxyl, butylated hydroxytoluene, and diphenyl ethylene confirm the involvement of radicals.

Electrochemical decarboxylative C3 alkylation of quinoxalin-2(1H)-ones with N-hydroxyphthalimide esters

Electrochemical decarboxylative C3 alkylation of a wide range of quinoxalin-2(1H)-ones under metal- and additive-free conditions was reported.

Transition-metal free C3-amidation of quinoxalin-2(1H)-ones using Selectfluor as a mild oxidant

A practical and efficient synthetic route to construct a variety of 3-amidated quinoxalin-2(1H)-ones was developed via transition-metal free direct oxidative amidation of quinoxalin-2(1H)-ones with amidates using Selectfluor reagent as a mild oxidant. This protocol features mild reaction conditions, operational simplicity, broad substrate scope, and good to excellent yields.

Selective COX-2 inhibitors as anticancer agents: a patent review (2014-2018)

INTRODUCTION

COX-2 is a key enzyme in the process of prostaglandins (PGs) synthesis. The products of this enzyme could play a major role as the mediators of the inflammatory response and some other medical states such as cancer. The design and synthesis of novel selective COX-2 inhibitors have always been attractive to researchers. This review discusses the structures of novel COX-2 inhibitors synthesized during the last five years and describes their efficacy as anticancer agents.

AREAS COVERED

It is well established that COX-2 is overexpressed in many different cancers and treatment with selective COX-2 inhibitors could relieve their symptoms and limit their adverse sequences.

EXPERT OPINION

The diversity of selective COX-2 inhibitors is mainly related to the types of scaffolds. Monocyclic, bicyclic, tricyclic, and acyclic scaffolds with different pharmacological effects and toxicological profiles could be found in the family of selective COX-2 inhibitors. The great interest of the researchers in this field is due to the importance of selective COX-2 inhibitors as a relatively safe and effective set of compounds which could present different properties such as antirheumatic, anti-inflammatory, antiplatelet, anti-Alzheimer's disease, anti-Parkinson's disease, and anticancer.

Revealing quinquennial anticancer journey of morpholine: A SAR based review

Morpholine, a six-membered heterocycle containing one nitrogen and one oxygen atom, is a moiety of great significance. It forms an important intermediate in many industrial and organic syntheses. Morpholine containing drugs are of high therapeutic value. Its wide array of pharmacological activity includes anti-diabetic, anti-emetic, growth stimulant, anti-depressant, bronchodilator and anticancer. Multi-drug resistance in cancer cases have emerged in the last few years and have led to the failure of many chemotherapeutic drugs. Newer treatment methods and drugs are being developed to overcome this problem. Target based drug discovery is an effective method to develop novel anticancer drugs. To develop newer drugs, previously reported work needs to be studied. Keeping this in mind, last five year's literature on morpholine used as anticancer agents has been reviewed and summarized in the paper herein.

Green synthesis of enantiopure quinoxaline alcohols using Daucus carota

Green chemistry comprises a new approach in the synthesis of biologically active compounds using biocatalysts, thus diminishing the hazards for human health and environmental pollution. Asymmetric bioreduction is one of the most widely employed strategies in chemoenzymatic synthesis to produce enantiomerically pure chiral alcohols. The present study highlights the use biocatalyst Daucus carota for selective bioreduction of quinoxaline ketones 1a-6a to their corresponding optically pure alcohols 1b-6b in high yields (up to 84%) and good enantioselectivity (up to 98%). The absolute configuration of the chiral product (R)-1-(3-methyl 7-nitroquinoxalin-2-yl) ethan-1-ol 2b was confirmed by X-ray crystallography studies. The chiral R-configuration of the products obtained was confirmed by absolute configuration studies and was assigned following anti-Prelogs rule. Quinoxaline pharmacophores form a part of well-known potent drug molecules; hence, the chiral products were studied for determination of their molecular properties using SwissADME property analyser. All the chiral products show no Lipinski rule violations and are expected to have good oral bioavailability. As per the molecular properties prediction studies, the compound 6b (R)-1-(6,7-dichloro-3- methylquinoxalin-2-yl) ethanol is observed to show the best physicochemical properties to be a good lead molecule. Thus, the sustainable methodology was developed, and it confirms the synthesis of novel quinoxaline chiral alcohols in a simple, inexpensive, and eco-friendly condition using D carota.

Ring-opening C(sp3)–C coupling of cyclobutanone oxime esters for the preparation of cyanoalkyl containing heterocycles enabled by photocatalysis

A ring-opening C(sp³)–C coupling of cyclobutanone oxime esters for the preparation of cyanoalkyl containing heterocycles was realized under visible-light or sunlight irradiation.

Highly efficient copper-catalyzed direct C–H amidation of quinoxalin-2(1H)-ones with amidates under microwave irradiation

A novel and convenient protocol for the construction of 3-amidated quinoxalin-2(1H)-ones was developed via copper-catalyzed direct oxidative amidation of quinoxalin-2(1H)-ones with amidates using K₂S₂O₈ as an oxidant, and under microwave irradiation.

Pd(TFA)2-catalyzed direct arylation of quinoxalinones with arenes

Pd(TFA)₂-catalyzed cross-dehydrogenative coupling reaction for the direct C-3 arylation of quinoxalin-2-ones with arenes is described.

Visible-light-promoted direct C–H/S–H cross-coupling of quinoxalin-2(1H)-ones with thiols leading to 3-sulfenylated quinoxalin-2(1H)-ones in air

A new and efficient visible-light-mediated strategy has been developed for the synthesis of 3-sulfenylated quinoxalin-2(1H)-ones via rhodamine B catalyzed C–H/S–H cross-coupling of quinoxalin-2(1H)-ones with thiols in air at room temperature.

Transition-metal-free decarboxylative C3-difluoroarylmethylation of quinoxalin-2(1H)-ones with α,α-difluoroarylacetic acids

A facile and efficient transition-metal-free decarboxylative radical coupling reaction of α,α-difluoroarylacetic acids with quinoxalin-2(1H)-ones has been developed under mild conditions.

Antitumoral activity of quinoxaline derivatives: A systematic review

Cancer is a leading cause of death and a major health problem worldwide. While many effective anticancer agents are available, the majority of drugs currently on the market are not specific, raising issues like the common side effects of chemotherapy. However, recent research hold promise for the development of more efficient and safer anticancer drugs. Quinoxaline and its derivatives are becoming recognized as a novel class of chemotherapeutic agents with activity against different tumors. The present review compiles and discusses studies concerning the therapeutic potential of the anticancer activity of quinoxaline derivatives, covering articles published between July 2013 and July 2018.

Design, synthesis, biological assessment and molecular docking studies of new 2-aminoimidazole-quinoxaline hybrids as potential anticancer agents

In a search for novel antiproliferative agents, a series of quinoxaline derivatives containing 2-aminoimidazole (8a-8x) were designed and synthesized. The structures of synthesized compounds were confirmed by IR, ¹H NMR, ¹³C NMR, Mass Spectroscopy and analyzed using HSQC, COSY, ROESY, HMBC techniques. The anticancer activity of all derivatives were evaluated for colon cancer and breast cancer cell lines by the MTT assay and acridine orange/ethidium bromide double staining method. The anti-cancer effect in human colon cancer (HCT-116) and breast cancer (MCF-7) cell lines exhibited that compounds 8a, 8s, 8t, 8w, 8x appeared as potent antiproliferative agents and especially inhibited the human colon cancer cell proliferation with percentage of inhibition by over 50%. The most active compound was (E)-4-phenyl-1-((quinoxalin-2-ylmethylene)amino)-1H-imidazol-2-amine (8a) with the highest inhibition for MCF-7 (83.3%) and HCT-116 (70%) cell lines after 48 and 24h, respectively. Molecular docking studies of these derivatives within c-kit active site as a validated target might be suggested them as appropriate candidates for further efforts toward more potent anticancer compounds.

Part II: New candidates of pyrazole-benzimidazole conjugates as checkpoint kinase 2 (Chk2) inhibitors

The development of checkpoint kinase 2 (Chk2) inhibitors for the treatment of cancer has been an ongoing and attractive objective in drug discovery. In this study, twenty-one feasible pyrazole-benzimidazole conjugates were synthesized to study their effect against Chk2 activity using Checkpoint Kinase Assay. The antitumor activity of these compounds was investigated using SRB assay. A potentiation effect of the synthesized Chk2 inhibitors was also investigated using the genotoxic anticancer drugs cisplatin and doxorubicin on breast carcinoma, (ER+) cell line (MCF-7). In vivo Chk2 and antitumor activities of 8d as a single-agent, and in combination with doxorubicin, were evaluated in breast cancer bearing animals induced by N-methylnitrosourea. The effect of 8d alone and in combination with doxorubicin was also studied on cell-cycle phases of MCF-7 cells using flow cytometry analysis. The results revealed their potencies as Chk2 inhibitors with IC50 ranges from 9.95 to 65.07 nM. Generally the effect of cisplatin or doxorubicin was potentiated by the effect of most of the compounds that were studied. The in vivo results indicated that the combination of 8d and doxorubicin inhibited checkpoint kinase activity more than either doxorubicin or 8d alone. There was a positive correlation between checkpoint kinase inhibition and the improvement observed in histopathological features. Single dose treatment with doxorubicin or 8d produced S phase cell cycle arrest whereas their combination created cell cycle arrest at G2/M from 8% in case of doxorubicin to 51% in combination. Gold molecular modelling studies displayed a high correlation to the biological results.

Metal-free oxidative coupling of quinoxalin-2(1H)-ones with arylaldehydes leading to 3-acylated quinoxalin-2(1H)-ones

An efficient protocol for the synthesis of 3-aroylquinoxalin-2(1H)-ones has been developed via a metal-free oxidative cross-coupling reaction of quinoxalin-2(1H)-ones with aryl aldehydes under mild conditions with good yields.

Photophysical properties of quinoxalin-2(1H)-ones: application in the preparation of an azide-based fluorogenic probe for the detection of hydrogen sulfide

Fluorescent quinoxalinones with good quantum yields were obtained and used in the preparation of a probe for the detection of H₂S.

Metal-free oxidative ring contraction of benzodiazepinones: an entry to quinoxalinones

Herein is reported a practical method for the construction of 3-benzoylquinoxalinones from benzodiazepinones in the presence of DMSO which serves both as a solvent and an oxidant.

α-Amylase Modulation: Discovery of Inhibitors Using a Multi-Pharmacophore Approach for Virtual Screening

Better control of postprandial hyperglycemia can be achieved by delaying the absorption of glucose resulting from carbohydrate digestion. Because α-amylase initiates the hydrolysis of polysaccharides, the design of α-amylase inhibitors can lead to the development of new treatments for metabolic disorders such as type II diabetes and obesity. In this study, a rational computer-aided approach was developed to identify novel α-amylase inhibitors. Three-dimensional pharmacophores were developed based on the binding mode analysis of six different families of compounds that bind to this enzyme. In a stepwise virtual screening workflow, seven molecules were selected from a library of 1.4 million. Five out of seven biologically tested compounds showed α-amylase inhibition, and the two most potent compounds inhibited α-amylase with IC₅₀ values of 17 and 27 μm. The scaffold benzylideneacetohydrazide was shared by four of the discovered inhibitors, emerging as a novel drug-like non-carbohydrate fragment and constituting a promising lead scaffold for α-amylase inhibition.

Solid Phase Synthesis of (Benzannelated) Six-Membered Heterocycles via Cyclative Cleavage of Resin-Bound Pseudo-Oxazolones

A solid supported procedure for the synthesis of benzoxazinones, dihydropyrazinones, quinoxalinones, and dihydrooxazinones using immobilized oxazolones in combination with difunctional nucleophiles as cleavage agent is presented. The scope of the novel method has been demonstrated through subsequent modification of the parent oxazolone scaffold on solid supports using conversions with electrophiles or CuAAC reactions to give functionalized pyrazin-2-ones. The described method allows the synthesis of the target heterocycles in good yields via three to five steps on solid phases with only one chromatographic purification step.

Pyrazino[2,3-g]quinoxaline-2,7-dione based π-conjugated polymers with affinity towards acids and semiconductor performance in organic thin film transistors

Pyrazino[2,3-g]quinoxaline-2,7-dione (PQx) is used as a building block for π-conjugated polymer semiconductors that demonstrate a strong acid affinity and ambipolar semiconductor performance in thin film transistors.