Antitumor agents. 181. Synthesis and biological evaluation of 6,7,2',3',4'-substituted-1,2,3,4-tetrahydro-2-phenyl-4-quinolones as a new class of antimitotic antitumor agents

Using Quinolin-4-Ones as Convenient Common Precursors for a Metal-Free Total Synthesis of Both Dubamine and Graveoline Alkaloids and Diverse Structural Analogues

The Rutaceae family is one of the most studied plant families due to the large number of alkaloids isolated from them with outstanding biological properties, among them the quinoline-based alkaloids Graveoline 1 and Dubamine 2. The most common methods for the synthesis of alkaloids 1 and 2 and their derivatives involves cycloaddition reactions or metal-catalyzed coupling processes but with some limitations in scope and functionalization of the quinoline moiety. As a continuation of our current studies on the synthesis and chemical transformation of 2-aminochalcones, we are reporting here an efficient metal-free approach for the total synthesis of alkaloids 1 and 2 along with their analogues with structural diversity, through a two-step sequence involving intramolecular cyclization, oxidation/aromatization, N-methylation and oxidative C-C bond processes, starting from dihydroquinolin-4-ones as common precursors for the construction of the structures of both classes of alkaloids.

Discovery, synthesis, activities, structure-activity relationships, and clinical development of combretastatins and analogs as anticancer drugs. A comprehensive review

Covering: 1982 to up to the end of 2022Bioassay guided purification of the extracts of Combretum caffrum led to the discovery of six series of combretastatins A-D with cytotoxic activities ranging from sub nM to >50 μM ED50's against a wide variety of cancer cell lines. Of these, cis-stilbenes combretastatins A-4 and A-1 were the most potent, exhibiting in vivo efficacy against a wide variety of tumor types in murine models. These antimitotic agents inhibited tubulin polymerization by reversibly binding to the colchicine binding sites. They inhibited tumor growth by a novel antivascular and antineogenesis mechanism in which they stopped blood flows to the blood vessels causing necrosis. Over 20 clinical trials of the phosphate prodrugs of combretastatin A-4 (CA4P) and A-1 (CA1P) showed objective and stable responses against many tumor types, with increased survival times of many patients along with the confirmed cure of certain patients inflicted with anaplastic thyroid cancers. Medicinal chemistry efforts led to the identification of three new leads (AVE8062, BNC105P, SCB01A) with improved in vitro and in vivo potency and an often-improved cellular spectrum. Unfortunately, these preclinical improvements did not translate clinically in any meaningful way. Objectively, CA4P remained the best compound and has garnered many Orphan drug designations by FDA. Clinical trials with tumor genetic mapping, particularly from previous responders, may help boost the success of these compounds in future studies. A comprehensive review of combretastatin series A-D, including bioassay guided discovery, total syntheses, and structure-activity relationship (SAR) studies, biological and mechanistic studies, and preclinical and clinical evaluations of the isolated combretastatins and analogs, along with the personal perspective of the author who originated this project, is presented.

Cu-Catalyzed Tandem C-N and C-C Bond Formation Leading to 4(1H)-Quinolones: A Scaffold with Diverse Biological Properties from Totally New Raw Materials in a Single Step

A novel Cu-catalyzed tandem C-N and C-C bond-formation reaction has been developed to furnish 2-substituted-4-(1H)-quinolones. 4-(1H)-quinolones play an important role in medicinal chemistry. Many 2-aryl(alkyl)-4(1H)-quinolones are found to exhibit diverse biological properties. While traditional methods have inherent issues [like starting materials with incompatible functional groups (NH2 and keto groups)], many modern methods either require activated starting materials (like Ynones) or employ expensive metals (Pd, Rh, Au, etc.) involving carbonylation using CO or metal complexes. Our protocol presents an environmentally friendly one-step method for the construction of these useful 2-substituted-4-(1H)-quinolones from easily available aryl boronic acid (or pinacolate ester) and nitriles as new raw materials, using a cheap Cu-catalyst and O2 (air) as a green oxidant. We further extended its application to the synthesis of various natural products, including the first formal total synthesis of punarnavine. A plausible mechanism involving an aryl nitrilium ion (formed due to the intermolecular C-N bond-forming coupling between aryl boron species and the nitrile group) followed by tandem intramolecular C-C bond formation has been proposed.

Enantioselective Synthesis of Aza-Flavanones with an All-Carbon Quaternary Stereocenter via NHC-Catalyzed Intramolecular Annulation

An enantioselective synthesis of functionalized aza-flavanone derivatives using the N-heterocyclic carbene-catalyzed intramolecular Stetter reaction of sulphoamido benzaldehydes has been reported. This procedure presents the first original approach for synthesizing chiral functionalized flavonoids at the 3-position, containing an all-carbon quaternary stereogenic center. This advancement significantly enriches the chemical toolbox for the preparation of complex nitrogen-containing compounds and opens up new avenues for further research and development in synthetic organic chemistry.

CVM-1118 (foslinanib), a 2-phenyl-4-quinolone derivative, promotes apoptosis and inhibits vasculogenic mimicry via targeting TRAP1

CVM-1118 (foslinanib) is a phosphoric ester compound selected from 2-phenyl-4-quinolone derivatives. The NCI 60 cancer panel screening showed CVM-1125, the major active metabolite of CVM-1118, to exhibit growth inhibitory and cytotoxic effects at nanomolar range. CVM-1118 possesses multiple bioactivities, including inducing cellular apoptosis, cell cycle arrest at G₂/M, as well as inhibiting vasculogenic mimicry (VM) formation. The TNF receptor associated protein 1 (TRAP1) was identified as the binding target of CVM-1125 using nematic protein organization technique (NPOT) interactome analysis. Further studies demonstrated CVM-1125 reduced the protein level of TRAP1 and impeded its downstream signaling by reduction of cellular succinate levels and destabilization of HIF-1α. The pharmacogenomic biomarkers associated with CVM-1118 were also examined by Whole Genome CRISPR Knock-Out Screening. Two hits (STK11 and NF2) were confirmed with higher sensitivity to the drug in cell knock-down experiments. Biological assays indicate that the mechanism of action of CVM-1118 is via targeting TRAP1 to induce mitochondrial apoptosis, suppress tumor cell growth, and inhibit vasculogenic mimicry formation. Most importantly, the loss-of-function mutations of STK11 and NF2 are potential biomarkers of CVM-1118 which can be applied in the selection of cancer patients for CVM-1118 treatment. CVM-1118 is currently in its Phase 2a clinical development.

Biological evaluation of polycyclic chalcone based acrylamides in human MCF-7 and HeLa cancer cell lines

Breast and cervical cancer account for the majority of cancer-narrated fatalities among women worldwide, necessitating the development of novel, effective therapeutic ways to combat the disease. In this study, we synthesized 6-methoxy naphthalene and anthracene-based acrylamide chalcone (NBA and ABA) and evaluated its activity for cell multiplication inhibition against two cancer cell lines from humans such as MCF-7 (Human Breast) and HeLa (Cervical) by MTT assay. Physiochemical characterization, such as FT-IR and NMR analyses, validated the synthesized NBA and ABA. Both NBA and ABA have shown antiproliferative action against two cancer cell lines, each with IC50 values of 38.46 and 48.25 μg/mL for HeLa cells and 38.02 and 36.35 μg/mL for MCF-7 cell lines. The results suggest that these acrylamide chalcones for cancer therapy at the lowest concentration. NBA and ABA could prevent cervical and breast cancer in-vitro, and their anti-cancer activity was closely related to methoxy-substituted naphthalene, anthracene ring, α, β-unsaturated carbonyl and amide group. According to docking data, the NBA and ABA have dock scores ranging from -8.7 to -11.44 kcal/mol. The highest dock score for compound ABA was -11.58 kcal/mol and compound NBA was -10.77 kcal/mol with Braf (5VAM) binding site.

Synthesis of Novel Pyrimido[4,5-b] Quinolines Containing Benzyloxy and 1,2,3-Triazole Moieties by DABCO as a Basic Catalyst

DABCO was used as a basic and inexpensive catalyst for the synthesis of some new benzyloxy pyrimido[4,5-b]quinoline derivatives and 1,2,3- triazole-fused pyrimido[4,5-b]quinolines by the one-pot multi-component reaction of various benzyloxy benzaldehydes or benzylic -1,2,3-triazol-4-yl-methoxy benzaldehydes with dimedone and 6-amino-1,3-dimethyluracil at 90 °C under the solvent-free condition.

Copper‐Catalyzed 1,2‐Dicarbonylative Cyclization of Alkenes with Alkyl Bromides via Radical Cascade Process

Herein, we developed a new procedure on 1,2-dicarbonylative cyclization of 4-aryl-1-butenes with alkyl bromides. Using simple copper catalyst, two molecules of carbon monoxide were introduced into the double bond with the formation of four new C-C bonds and a new ring. Various α-tetralones and 2,3-dihydroquinolin-4-ones were formed in moderate to good yields.

Advances in antitumor research of CA-4 analogs carrying quinoline scaffold

Combretastatin A-4 (CA-4) is a potent inhibitor of tubulin polymerization and a colchicine binding site inhibitor (CBSI). The structure-activity relationship study of CA-4 showed that the cis double bond configuration and the 3,4,5-trimethoxy group on the A ring were important factors to maintain the activity of CA-4. Therefore, starting from this condition, chemists modified the double bond and also substituted 3,4,5-trimethoxyphenyl with various heterocycles, resulting in a new generation of CA-4 analogs such as chalcone, Flavonoid derivatives, indole, imidazole, etc. Quinoline derivatives have strong biological activity and have been sought after by major researchers for their antitumor activity in recent years. This article reviews the research progress of novel CA-4 containing quinoline analogs in anti-tumor from 1992 to 2022 and expounds on the pharmacological mechanisms of these effective compounds, including but not limited to apoptosis, cell cycle, tubulin polymerization inhibition, immune Fluorescence experiments, etc., which lay the foundation for the subsequent development of CA-4 containing quinoline analogs for clinical use.

Relay Photocatalytic Reaction of N-Aryl Amino Acids and 2-Bromo-3,3,3-trifluoropropene: Synthesis of 4-(Difluoromethylidene)-tetrahydroquinolines

The bulk industrial chemical 2-bromo-3,3,3-trifluoropropene (BTP) was first employed as a coupling partner in photocatalytic defluorinative reactions with N-aryl amino acids. Photoredox activation of the C(sp²)-Br bond of the resultant 2-bromo-1,1-difluoroalkenes generates gem-difluoro vinyl radicals for further radical cyclization. Various 4-(difluoromethylidene)-tetrahydroquinolines were assembled in good yields by combining two photoredox cycles with a single photocatalyst.

Insights on a new sulfonamide chalcone with potential antineoplastic application

Chalcones (E)-1,3-diphenyl-2-propene-1-ones, a class of biosynthetic precursor molecules of flavonoids, have a wide variety of biological applications. Besides the natural products, many synthetic derivatives and analogs became an object of continued interest in academia and industry. In this work, a synthesis and an extensive structural study were performed on a sulfonamide chalcone 1-Benzenesulfonyl-3-(4-bromobenzylidene)-2-(2-chlorophenyl)-2,3-dihydro-1H-quinolin-4-one with potential antineoplastic application. In addition, in silico experiments have shown that the sulfonamide chalcone fits well in the ligand-binding site of EGFR with seven μ-alkyl binding energy interactions on the ligand-binding site. Finally, the kinetic stability and the pharmacophoric analysis for EGFR indicated the necessary spatial characteristics for potential activity of sulfonamide chalcone as an antagonist.

Diastereoselective Synthesis of Dihydro-quinolin-4-ones by a Borane-Catalyzed Redox-Neutral endo-1,7-Hydride Shift

The borane-catalyzed synthesis of dihydroquinoline-4-ones is developed. The amino-substituted chalcones undergo a 1,7-hydride shift upon Lewis acid activation to form a zwitterionic iminium enolate, which collapses to the dihydroquinoline-4-one scaffold. The reaction proceeds in high yields (75-99%) with an excellent diastereoselectivity of up to >99:1 (cis:trans). The reaction mechanism is investigated by kinetic, isotope labeling, and computational experiments.

A highly efficient and green approach for the synthesis of pyrimido[4,5-b]quinolines using N,N-diethyl-N-sulfoethanaminium chloride

A highly efficient and green protocol for the synthesis of pyrimido[4,5-b]quinolines has been described. The one-pot multicomponent reaction of dimedone with arylaldehydes and 6-amino-1,3-dimethyluracil in the presence of N,N-diethyl-N-sulfoethanaminium chloride ([Et3N–SO3H][Cl]) as an ionic liquid (IL) catalyst under solvent-free conditions afforded the mentioned compounds in high yields and short reaction times. Our protocol is superior to many of the reported protocols in terms of two or more of these factors: the reaction times, yields, conditions (solvent-free versus usage of organic solvents), temperature and catalyst amount.

Palladium-catalyzed 1,2-amino carbonylation of 1,3-dienes with (N-SO2Py)-2-iodoanilines: 2,3-dihydroquinolin-4(1H)-ones synthesis

A palladium-catalyzed 1,2-amino carbonylation of 1,3-dienes with (N-SO₂Py)-2-iodoanilines has been developed for the construction of 2,3-dihydroquinolin-4(1H)-one scaffolds.

Palladium-catalyzed directing group assisted and regioselectivity reversed cyclocarbonylation of arylallenes with 2-iodoanilines

A palladium-catalyzed regioselective cyclocarbonylation of N-(2-pyridyl)sulfonyl (N-SO₂Py)-2-iodoanilines with allenes was developed. The regioselectivity of arylallenes was reversed. Control experiments and DFT calculations were performed to understand the reaction details.

One-Pot Synthesis of 4-Quinolone via Iron-Catalyzed Oxidative Coupling of Alcohol and Methyl Arene

Herein, we describe the iron(III)-catalyzed oxidative coupling of alcohol/methyl arene with 2-amino phenyl ketone to synthesize 4-quinolone. Alcohols and methyl arenes are oxidized to the aldehyde in the presence of an iron catalyst and di-tert-butyl peroxide, followed by a tandem process, condensation with amine/Mannich-type cyclization/oxidation, to complete the 4-quinolone ring. This method tolerates various kinds of functional groups and provides a direct approach to the synthesis of 4-quinolones from less functionalized substrates.

Chelating Group Enabled Palladium-Catalyzed Regiodivergent Carbonylative Synthesis of 2,3-Dihydroquinolin-4(1H)-ones

A new procedure on palladium-catalyzed carbonylative cyclization of N-(2-pyridyl)sulfonyl (N-SO₂ Py)-2-iodoanilines with terminal alkenes has been developed for the rapid construction of dihydroquinolin-4(1H)-one scaffolds. Enabled by the chelating group and using benzene-1,3,5-triyl triformate (TFBen) as the CO source, both aromatic and aliphatic alkenes were smoothly transformed into the corresponding 2,3-dihydroquinolin-4(1H)-ones in good yields with excellent regioselectivities. Notably, the reaction of aromatic alkenes produces 2-aryl-2,3-dihydroquinolin-4(1H)-ones, while 3-alkyl-2,3-dihydroquinolin-4(1H)-ones were obtained when aliphatic alkenes were used. This protocol has been applied in the synthesis of antitumor agent A as well.

An Overview of Privileged Scaffold: Quinolines and Isoquinolines in Medicinal Chemistry as Anticancer Agents

Cancer is one of the most difficult diseases and causes of death for many decades. Many pieces of research are continuously going on to get a solution for cancer. Quinoline and isoquinoline derivatives have shown their possibilities to work as an antitumor agent in anticancer treatment. The members of this privileged scaffold quinoline and isoquinoline have shown their controlling impacts on cancer treatment through various modes. In particular, this review suggests the current scenario of quinoline and isoquinoline derivatives as antitumor agents and refine the path of these derivatives to find and develop new drugs against an evil known as cancer.

A novel organic–inorganic hybrid material: production, characterization and catalytic performance for the reaction of arylaldehydes, dimedone and 6-amino-1,3-dimethyluracil

A novel silica-based organic–inorganic hybrid catalyst was prepared, characterized and applied for the synthesis of pyrimido[4,5-b]quinolines.

Carbene-Catalyzed Enantioselective Decarboxylative Annulations to Access Dihydrobenzoxazinones and Quinolones

A direct decarboxylative strategy for the generation of aza-o-quinone methides (aza-o-QMs) by N-heterocyclic carbene (NHC) catalysis has been discovered and explored. This process requires no stoichiometric additives in contrast with current approaches. Aza-o-QMs react with trifluoromethyl ketones through a formal [4+2] manifold to access highly enantioenriched dihydrobenzoxazin-4-one products, which can be converted to dihydroquinolones through an interesting stereoretentive aza-Petasis-Ferrier rearrangement sequence. Complementary dispersion-corrected density functional theory (DFT) studies provided an accurate prediction of the reaction enantioselectivity and lend further insight to the origins of stereocontrol. Additionally, a computed potential energy surface around the major transition structure suggests a concerted asynchronous mechanism for the formal annulation.

Synthesis of dihydroquinolinones via iridium-catalyzed cascade C-H amidation and intramolecular aza-Michael addition

An iridium-catalyzed annulation of chalcones with sulfonyl azides via cascade C-H amidation and intramolecular aza-Michael addition was developed, affording a variety of 2-aryl-2,3-dihydro-4-quinolones in moderate to good yields. This reaction features easy operation, readily available starting materials, and the cascade formation of two C-N bonds in one pot.

Induction of cytotoxicity and apoptosis in FLT3 mutant expressing cells using novel pyrimido cyanoacrylates and quinoline derivatives

BACKGROUND

Aberrant activation of FMS-like tyrosine kinase 3 (FLT3) is associated with acute myeloid leukemia (AML). Leukemic cells expressing constitutively active FLT3 mutants are resistance to the current cancer therapies (radiotherapy and chemotherapy); hence, there is an increased interest to identify new agents for the treatment of AML. The main aim of this study was evaluating cytotoxic effects of novel pyrimidocyanoacrylates and quinoline derivatives on FLT3 overexpressing cells.

MATERIALS AND METHODS

Five novel pyrimidocyanoacrylates & 2-chloro 3-carbaldehyde quinolone derivative compounds, E1QAC1, E1QAC2, E1QAC3, E1QAC4, and E1QAC5 were designed and synthesized at the Department of Chemistry, Faculty of Sciences, Ferdowsi University, Mashhad, Iran. FDC-P1 cells expressing human wild-type FLT3 (FD-FLT3-WT) and internal tandem duplication (ITD) mutants (FD-FLT3-ITD) used in this study. The cells maintained in DMEM medium supplemented with 10% fetal calf serum (FCS) and murine granulocyte-macrophage colony stimulating factor (mGM-CSF). Potency for induction of cytotoxicity (IC₅₀ value) and apoptosis was determined after treating the cells with concentration of the compounds by resazurin assay. Bax and Bcl2 activation status was also investigated by Western blot analysis.

RESULTS

All the compounds had concentration-dependent effects on inhibition of cell proliferation and induction of apoptosis in both cell lines. E1QAC4 was the most potent compound for inhibition of cell proliferation (with IC50 value of 19 μM) and apoptosis induction in the FLT3-WT cells. However, FD-FLT3-ITD cells were nearly five-times more resistant to all the compounds (except than E1QAC2) that the FLT3-WT expressing cells. Western blotting results also showed that FD-FLT3-ITD cells had lower levels of Bax and higher levels of Bcl2 than the FD-FLT3-WT cells.

CONCLUSION

The five novel heterocyclic compounds (E1QAC1-5) had cytotoxic effects and induced apoptosis in FD-FLT3 cells. Therefore, it is worthwhile to consider them as potential lead compound for development of new therapeutic agents for AML patients.

Antibacterial and antioxidant activities for natural and synthetic dual-active compounds

Antimicrobial resistance is widely recognized as a grave threat to global health in the 21st century, since the past decades have seen a dramatic increase in human-pathogenic bacteria that are resistant to one or multiple antibiotics. New antimicrobial agents are urgently required, particularly in the treatment of chronic infections such as cystic fibrosis, often associated with persistent colonization by drug-resistant pathogens and epithelial damage by pulmonary oxidative stress. In such events, it would be favourable to find agents that could have antioxidant and antibacterial activities combined in one molecule. The discovery of compounds that can show a dual-target activity considerably increased in the last years, reflecting the growing confidence that this new approach could lead to better therapeutic solutions for complex multigenic diseases. The aim of this review is to report those natural and synthetic compounds displaying significant antioxidant and antibacterial activities. In recent years there has been a growing attention on plant-derived antimicrobials as an alternative to antibiotics, for their efficacy and low tendency in developing bacterial resistance. Moreover, it was found that some natural products could enhance the activity of common antibiotics displaying a synergistic effect. We then report some selected synthetic compounds with an in-built capacity to act on two targets or with the combination in a single structure of two pharmacophores with antioxidant and antibacterial activities. Recent literature instances were screened and the most promising examples of dual-active antibacterial-antioxidant molecules were highlighted.

CHM-1, a novel microtubule-destabilizing agent exhibits antitumor activity via inducing the expression of SIRT2 in human breast cancer cells

Breast cancer is a major public health problem throughout the world. In this report, we investigated whether CHM-1, a novel synthetic antimitotic agent could be developed into a potent antitumor agent for treating human breast cancer. CHM-1 induced growth inhibition in MDA-MB-231, MDA-MB-453 and MCF-7 cells in a concentration-dependent manner. Importantly, CHM-1 is less toxic to normal breast (HBL-100) cells. CHM-1 interacted with tubulin, markedly inhibited tubulin polymerization, and disrupted microtubule organization. Proteins from control and CHM-1-treated animal tumor specimens were analyzed by two-dimensional electrophoresis and MALDI-TOF mass spectrometry. Our results indicated that CHM-1 increased the expression of SIRT2 protein, an NAD-dependent tubulin deacetylase. A prodrug strategy was also investigated to address the problem of low aqueous solubility and low bioavailability of the antitumor agent CHM-1. The water-soluble prodrug of CHM-1 (CHM-1-P) was synthesized. After oral and intravenous administration, CHM-1-P induced a dose-dependent inhibition of tumor growth. The aforementioned excellent anti-tumor activity profiles of CHM-1 and its prodrug CHM-1-P, suggests that CHM-1-P deserves to further develop as a clinical trial candidate for treating human breast carcinoma.

Highly efficient asymmetric construction of novel indolines and tetrahydroquinoline derivatives via aza-Barbier/C–N coupling reaction

An efficient approach towards stereoselective synthesis of chiral indolines and tetrahydroquinolines via Zn-mediated allylation of chiral-N-tert-butanesulfinyl imines and intramolecular C–N cross-coupling is described.

Intercalation of a Zn(II) complex containing ciprofloxacin drug between DNA base pairs

In this study, an attempt has been made to study the interaction of a Zn(II) complex containing an antibiotic drug, ciprofloxacin, with calf thymus DNA using spectroscopic methods. It was found that Zn(II) complex could bind with DNA via intercalation mode as evidenced by: hyperchromism in UV-Vis spectrum; these spectral characteristics suggest that the Zn(II) complex interacts with DNA most likely through a mode that involves a stacking interaction between the aromatic chromophore and the base pairs of DNA. DNA binding constant (K_b = 1.4 × 10⁴ M^-1) from spectrophotometric studies of the interaction of Zn(II) complex with DNA is comparable to those of some DNA intercalative polypyridyl Ru(II) complexes 1.0 -4.8 × 10⁴ M^-1. CD study showed stabilization of the right-handed B form of DNA in the presence of Zn(II) complex as observed for the classical intercalator methylene blue. Thermodynamic parameters (ΔH < 0 and ΔS < 0) indicated that hydrogen bond and Van der Waals play main roles in this binding prose. Competitive fluorimetric studies with methylene blue (MB) dye have shown that Zn(II) complex exhibits the ability of this complex to displace with DNA-MB, indicating that it binds to DNA in strong competition with MB for the intercalation.