Antivascular and antitumor evaluation of 2-amino-4-(3-bromo-4,5-dimethoxy-phenyl)-3-cyano-4H-chromenes, a novel series of anticancer agents

Design and evaluation of sulfadiazine derivatives as potent dual inhibitors of EGFRWT and EGFRT790M: integrating biological, molecular docking, and ADMET analysis

A series of derivatives (5-14) were synthesized through the diazotization of sulfadiazine with active methylene compounds. The chemical structures of these newly designed compounds were validated through spectral and elemental analysis techniques. The antiproliferative potential of derivatives 5-14 was assessed against three distinct cancer cell lines (A431, A549, and H1975) using the MTT assay. The results revealed that compounds 8, 12, and 14 exhibited the most potent antiproliferative activity, with IC50 values ranging from 2.31 to 7.56 μM. Notably, these values were significantly lower than those of known EGFR inhibitors, including erlotinib, gefitinib, and osimertinib, suggesting the potential of these derivatives as novel antiproliferative agents. Furthermore, compound 12 was identified as the most potent inhibitor of both EGFRWT and EGFRT790M protein kinases, with IC50 values of 14.5 and 35.4 nM, respectively. These results outperformed those of gefitinib and osimertinib, which exhibited IC50 values of 18.2 and 368.2 nM, and 57.8 and 8.5 nM, respectively. Molecular docking studies of compounds 8, 12, and 14 within the ATP-binding sites of both EGFRWT and EGFRT790M corroborated the in vitro results when compared to erlotinib, gefitinib, and osimertinib. The docking results indicated that compound 8 exhibited a favorable binding affinity for both EGFRWT and EGFRT790M, with binding scores of -6.40 kcal mol-1 and -7.53 kcal mol-1, respectively, which were comparable to those of gefitinib and osimertinib, with binding scores of -8.01 and -8.72 kcal mol-1, respectively. Furthermore, an assessment of the most promising EGFR inhibitors (8, 12, and 14) using the egg-boiled method for their in silico ADME properties revealed significant lipophilicity, blood-brain barrier (BBB) penetration, and gastrointestinal (GIT) absorption. Collectively, our designed analogs, particularly compounds 8, 12, and 14, exhibit promising dual antiproliferative and EGFRWT and EGFRT790M kinase inhibitory properties, positioning them as efficient candidates for further therapeutic development.

5-Oxo-7,7-Dimethyl-5,6,7,8-Tetrahydro-4-H-Chromene Bearing N, N-Dimethylaniline as Turn-Off Fluorescent Chemosensor for Picric Acid in Real Water Sample

We have synthesized a one-pot, three-component pyran-based fluorescence chemosensor using onion extract as a green catalyst. The confirmed structure of the 1:2 binding of receptor SPR-2-picric acid adduct revealed that the pyran-based receptor accommodated two guest picric acid molecules through non-covalent interactions. UV-Vis and fluorescence spectroscopy show high selectivity and sensitivity towards picric acid. The 1D/2D NMR and Job's plot analysis show the complexation and stoichiometric binding of the receptor SPR-2 with picric acid are 1:2. The 1H NMR spectral studies confirm that the formation of receptor SPR-2-picric acid adduct via weak hydrogen bonding. The cooperativity of the receptor SPR-2-picric acid adduct shows negative cooperativity due to the weak hydrogen bonding of receptor SPR-2 and picric acid. Further, the density functional theory (DFT) confirmed the molecular level interaction of the SPR-2 and receptor SPR-2-Picric acid adduct. The receptor was effectively used to assess picric acid concentrations in real water samples.

Design, spectroscopic characterizations, and biological investigation of oxospiro[chromine-4,3-indolene]-based compounds as promising antiproliferative EGFR inhibitors and antimicrobial agents

Utilizing microwave heating and an aqueous saturated solution of K2CO3 as a catalyst, a rapidone-pot synthesis of oxospiro[chromene-4.3-indoline] derivatives was produced in high yields. The experimental results confirmed that the saturated solution of K2CO3 gives outstanding yield to dangerous metals and strong bases during investigations into high-performance catalysts. The used catalyst is green, affordable, incredibly mild, and widely accessible. However, it generates samples, reduces the amount of byproducts, and is expected to be used in industrial-scale heterocyclic derivatives. New oxospiro[chromene-4.3-indoline] derivatives have been created from various isatin by condensing with various phenols. The biological activities results showed that when compared to erlotinib, the derivatives 3b, 4b, 5b, and 6b were the most effective analogues on A549, MCF-7, HepG-2, and HCT-116 cells, with an IC50 range of 3.32 to 11.88 µM. In A549 cells, compounds 3b, 4b, 5b, and 6b induced apoptosis, as shown by the up-regulation of Bax, the up-regulation of Bcl-2, and the stimulation of caspase-3 and -9. With IC50 value of 0.19 ± 0.09, compound3b was demonstrated to be the most effective against EGFRWT. Compounds 4b and 6b have good antibacterial activity toward Staphylococcus aureus, comparable to ciprofloxacin, and about half as much activity as ampicillin, according to the MIC value. Compound 6b's MIC is about 25% lower than clotrimazole drug. The in silico molecular docking outcomes of compounds 3b, 4b, 5b, and 6b in the EGFR active site depicted their ability to adopt essential binding interactions compared to the reference Erlotinib. Moreover, the investigation of the physicochemical properties of the most promising dual acting antiproliferative and antimicrobial compounds 4b and 6b through the egg-boiled method illustrated acceptable lipophilicity, GIT absorption, and blood-brain barrier penetration characteristics.

Design and Synthesis of Novel N-Benzylidene Derivatives of 3-Amino-4-imino-3,5-dihydro-4H-chromeno[2,3-d]pyrimidine under Microwave, In Silico ADME Predictions, In Vitro Antitumoral Activities and In Vivo Toxicity

The synthesis of a series of new N-benzylidene derivatives of 3-amino-4-imino-3,5-dihydro-4H-chromeno[2,3-d]pyrimidine 10(a-l) bearing two points of molecular diversity is reported. These new compounds were synthesized in five steps including two steps under microwave dielectric heating. They were fully characterized using 1H and 13C NMR, FTIR and HRMS. The in silico physicochemical properties of compounds 10(a-l) were determined according to Lipinski's rules of five (RO5) associated with the prediction of their bioavailability. These new compounds 10(a-l) were tested for their antiproliferative activities in fibroblasts and eight representative human tumoral cell lines (Huh7 D12, Caco2, MDA-MB231, MDA-MB468, HCT116, PC3, MCF7 and PANC1). Among them, the compounds 10h and 10i showed sub-micromolar cytotoxic activity on tumor cell lines (0.23 < IC50 < 0.3 μM) and no toxicity on fibroblasts (IC50 > 25 μM). A dose-dependent inhibition of Store-Operated Ca+2 Entry (SOCE) was observed in the HEK293 cell line with 10h. In vitro embryotoxicity and angiogenesis on the mCherry transgenic zebrafish line showed that 10h presented no toxic effect and no angiogenic effect on embryos with a dose of 5 μM at 72 hpf.

Tubulin inhibitors. Selected scaffolds and main trends in the design of novel anticancer and antiparasitic agents

Design of tubulin inhibitors as anticancer drugs dynamically developed over the past 20 years. The modern arsenal of potential tubulin-targeting anticancer agents is represented by small molecules, monoclonal antibodies, and antibody-drug conjugates. Moreover, targeting tubulin has been a successful strategy in the development of antiparasitic drugs. In the present review, an overall picture of the research and development of potential tubulin-targeting agents using small molecules between 2018 and 2023 is provided. The data about some most often used and prospective chemotypes of small molecules (privileged heterocycles, moieties of natural molecules) and synthetic methodologies (analogue-based, fragment-based drug design, molecular hybridization) applied for the design of novel agents with an impact on the tubulin system are summarized. The design and prospects of multi-target agents with an impact on the tubulin system were also highlighted. Reported in the review data contribute to the "structure-activity" profile of tubulin-targeting small molecules as anticancer and antiparasitic agents and will be useful for the application by medicinal chemists in further exploration, design, improvement, and optimization of this class of molecules.

Synthesis and Characterization of a New Class of Chromene-Azo Sulfonamide Hybrids as Promising Anticancer Candidates with the Exploration of Their EGFR, hCAII, and MMP-2 Inhibitors Based on Molecular Docking Assays

In this study, novel selective antitumor compounds were synthesized based on their fundamental pharmacophoric prerequisites associated with EGFR inhibitors. A molecular hybridization approach was employed to design and prepare a range of 4H-chromene-3-carboxylates 7a-g, 8, and 11a-e derivatives, each incorporating a sulfonamide moiety. The structures of these hybrid molecules were verified using comprehensive analytical and spectroscopic techniques. During the assessment of the newly synthesized compounds for their anticancer properties against three tumor cell lines (HepG-2, MCF-7, and HCT-116), compounds 7f and 7g displayed remarkable antitumor activity against all tested cell lines, outperforming the reference drug Cisplatin in terms of efficacy. Consequently, these promising candidates were selected for further investigation of their anti-EGFR, hCAII, and MMP-2 potential, which exhibited remarkable effectiveness against EGFR and MMP2 when compared to Sorafenib. Additionally, docking investigations regarding the EGFR binding site were implemented for the targeted derivatives in order to attain better comprehension with respect to the pattern in which binding mechanics occur between the investigated molecules and the active site, which illustrated a higher binding efficacy in comparison with Sorafenib.

Tandem phospha-Michael addition/cyclization/dehydration of 2-hydroxychalcones with H-phosphine oxides for the synthesis of 4-phosphorylated 4H-chromenes

A Hg(OTf)2-catalyzed tandem phospha-Michael addition/cyclization/dehydration of 2-hydroxychalcones with H-phosphine oxides is presented. This protocol provides a new and supplementary approach for the preparation of 4-phosphorylated 4H-chromenes in good yields (up to 99%). In addition, this domino reaction allows the successful construction of two new C-P and C-O bonds in a one-pot operation.

Recyclable mesalamine-functionalized magnetic nanoparticles (mesalamine/GPTMS@SiO2@Fe3O4) for tandem Knoevenagel-Michael cyclocondensation: grinding technique for the synthesis of biologically active 2-amino-4H-benzo[b]pyran derivatives

In the present study, mesalamine-functionalized on magnetic nanoparticles (mesalamine/GPTMS@SiO2@Fe3O4) is fabricated as an efficient and magnetically recoverable nanocatalyst. The as-prepared nanocatalyst was successfully synthesized in three steps using a convenient and low-cost method via modification of the surface of Fe3O4 nanoparticles with silica and GPTMS, respectively, to afford GPTMS@SiO2@Fe3O4. Finally, treatment with mesalamine as a powerful antioxidant generates the final nanocatalyst. Then, its structure was characterized by FT-IR, SEM, TEM, EDX, XRD, BET, VSM, and TGA techniques. The average size was found to be approximately 38 nm using TEM analysis and the average crystallite size was found to be approximately 27.02 nm using XRD analysis. In particular, the synthesized nanocatalyst exhibited strong thermal stability up to 400 °C and high magnetization properties. The activity of the synthesized nanocatalyst was evaluated in the tandem Knoevenagel-Michael cyclocondensation of various aromatic aldehydes, dimedone and malononitrile under a dry grinding method at room temperature to provide biologically active 2-amino-4H-benzo[b]pyran derivatives products in a short time with good yields. The presented procedure offers several advantages including gram-scale synthesis, good green chemistry metrics (GCM), easy fabrication of the catalyst, atom economy (AE), no use of column chromatography, and avoiding the generation of toxic materials. Furthermore, the nanocatalyst can be reused for 8 cycles with no loss of performance by using an external magnet.

Fe3O4@nano-almondshell/Si(CH2)3/2-(1-piperazinyl)ethylamine as an effective magnetite almond shell-based nanocatalyst for the synthesis of dihydropyrano[3,2-c]chromene and tetrahydrobenzo[b]pyran derivatives

The preparation and design of nano-catalysts based on magnetic biopolymers as green and biocompatible nano-catalysts have made many advances. This paper deals with the preparation of magnetite biopolymer-based Brønsted base nano-catalyst from a nano-almond (Prunus dulcis) shell. This magnetite biopolymer-based nano-catalyst was obtained through a simple process based on the core-shelling of nano-almond shell and Fe₃O₄ NPs and then the immobilization of 3-chloropropyltrimethoxysilane as linker and 2-aminoethylpiperazine as a basic section. Structural and morphological analysis of this magnetite biopolymer-based nano-catalyst were done using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, Thermogravimetric analysis, Vibrating sample magnetization, Energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller, and Transmission electron microscopy techniques. The performance of the synthesized Fe₃O₄@nano-almondshell/Si(CH₂)₃/2-(1-piperazinyl)ethylamine as a novel magnetite biopolymer-based nano-catalyst for the synthesis of dihydropyrano[3,2-c]chromene and tetrahydrobenzo[b]pyran was investigated and showed excellent efficiency.

Preparation and characterization of the h-BN/Fe3O4/APTES-AMF/CuII nanocomposite as a new and efficient catalyst for the one-pot three-component synthesis of 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles

The intriguing features of surface-engineered hexagonal two-dimensional boron nitride (h-BN) nanostructures have captivated the immense interest of researchers working in the arena of materials science. Inspired by striking attributes exhibited by h-BN nanosheets as the support material, we devoted our efforts towards synthesizing a novel magnetically retrievable h-BN/Fe₃O₄/APTES-AMF/Cu^II catalytic system, which was then comprehensively characterized using various techniques including SEM, TEM, EDX, SEM-based elemental mapping, ED-XRF, AAS, XRD, FT-IR, VSM, XPS, TGA, and BET. Further, the catalytic potential of h-BN/Fe₃O₄/APTES-AMF/Cu^II nanocomposites was investigated in the one-pot multicomponent coupling reaction to gain access to a library of biologically active 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles under ambient conditions. In addition, the use of green solvent, facile magnetic recoverability, and reusability of up to six successive runs made this protocol environmentally benign and economical. This work throws light on the development of covalently functionalized 2D-BN nanostructure-based copper catalysts and establishes its significance in furnishing industrially demanding products that would pave the way towards sustainable chemistry.

Brønsted acid catalyzed mechanochemical domino multicomponent reactions by employing liquid assisted grindstone chemistry

Here, we have demonstrated a metal-free energy-efficient mechanochemical approach for expedient access to a diverse set of 2-amino-3-cyano-aryl/heteroaryl-4H-chromenes, tetrahydrospiro[chromene-3,4'-indoline], 2,2'-aryl/heteroarylmethylene-bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) as well as tetrahydro-1H-xanthen-1-one by employing the reactivity of 5,5-dimethylcyclohexane-1,3-dione/cyclohexane-1,3-dione with TsOH⋅H₂O as Brønsted acid catalyst under water-assisted grinding conditions at ambient temperature. The ability to accomplish multiple C-C, C=C, C-O, and C-N bonds from readily available starting materials via a domino multicomponent strategy in the absence of metal-catalyst as well as volatile organic solvents with an immediate reduction in the cost of the transformation without necessitates complex operational procedures, features the significant highlights of this approach. The excellent yield of the products, broad functional group tolerances, easy set-up, column-free, scalable synthesis with ultralow catalyst loading, short reaction time, waste-free, ligand-free, and toxic-free, are other notable advantages of this approach. The greenness and sustainability of the protocol were also established by demonstrating several green metrics parameters.

Visible-light-induced alkylation of 2-iminochromene

A metal-free, photochemical protocol for C-4 alkylation of 2-iminochromene has been developed by employing the naturally abundant feedstock carboxylic acid. Selective C-4 alkylation under photoredox conditions to access C-4 alkylated 2-iminochromene in up to 81% yield was achieved. In addition, biologically relevant chromophores can be easily incorporated under this protocol.

Loading of g-C3 N4 on Core-Shell Magnetic Mesoporous Silica Nanospheres as a Solid Base Catalyst for the Green Synthesis of some Chromene Derivatives under Different Conditions

Using heterogeneous basic catalysts has a great importance in chemical reactions because of their advantages (such as easy separation and thermal stability at harsh conditions) over homogeneous catalysts. In this study, magnetic mesoporous silica nanoparticles (mSiO2 ) containing graphitic carbon nitride layers (mSiO2 /g-C3 N4 (x)) were fabricated through a facile process (x signifies the amount of melamine applied during synthesis). Graphitic carbon nitride layers were decorated on mSiO2 by calcination of immobilized melamine (as graphitic carbon nitride precursor) on mSiO2 in the last step of catalyst synthesis. The structure of the prepared catalysts was confirmed using XRD, BET, FESEM, EDX, elemental mapping and TEM methods. The catalytic efficiency of the so-obtained solid base composite was investigated for the synthesis of some dihydropyranochromenes and spiro-dihydropyranochromenes under thermal and microwave conditions. Using mSiO2 /g-C3 N4 (x) led to high yields under green conditions and in short reaction times and without a decrease in catalytic activity after four consecutive cycles.

Functionalization of magnetic nanoparticles by creatine as a novel and efficient catalyst for the green synthesis of 2-amino-4H-chromene derivatives

By employing the naturally-originated molecule of creatine, Fe₃O₄@SiO₂-creatine as an environmentally benign magnetic organometallic nanobiocatalyst was successfully prepared via a convenient and green route. Then to acquire an inclusive comprehension of different properties of the catalyst, it was studied by various characterization techniques such as FT‐IR, FE-SEM, TEM, EDX, XRD, and VSM analyses. It was found that the size distribution of nanoparticles was an average diameter size of 70 nm. To examine the catalytic activity, it was applied in sequential knoevenagel condensation-Michael addition room temperature reaction of dimedone, malononitrile, and different substituted aromatic aldehydes to produce a variety of 2-amino-tetrahydro-4H-chromene-3-carbonitrile derivatives in a single step. Among the multiple outstanding advantages that can be mentioned for this work, some of the most noticeable ones include: affording the products in short reaction times with high yields, operating the reaction at ambient conditions and ease of catalyst separation.

Marine cuttlefish derived 2H-benzochromenone: Pharachromenone as a dual inhibitor of pro-inflammatory 5-lipoxygenase and cyclooxygenase-2

Cephalopod cuttlefish, Sepia pharaonis, has been considered as a commercially important resource, which is widely regarded as nutritious food in the southwest of Indian and Mediterranean coasts. Chemical analysis of the crude extract of S. pharaonis resulted in the isolation of an undescribed 2H-benzochromenone, pharachromenone, which was characterized as methyl-2″-(7-hydroxy-4-(5'-methylpent-5'-en-1'-yl-oxy-methyl)-2-oxo-2H-benzo[h]chromen-5-yl-methyl)-butanoate by mass and nuclear magnetic resonance spectral experiments. Pharachromenone revealed effective biopotency against 5-lipoxygenase (IC₅₀ 1.85 mM) and cyclooxygenase-2 (IC₅₀ 0.52 mM) than that displayed by nonsteroidal anti-inflammatory drug ibuprofen (IC₅₀ 4.36 mM, p < .05). Promising antioxidant property for pharachromenone (IC₅₀ 1.42-1.61 mM) compared with those exhibited by antioxidative agents butylated hydroxyl anisole (BHA) and α-tocopherol (IC₅₀ 1.40-1.90 mM) could conceivably validate its dual inhibition potential against 5-lipoxygenase and cyclooxygenase-2. Greater electronic parameters, lesser steric bulkiness, along with acceptable lipophilic-hydrophobic balance significantly contributed toward its promising anti-inflammatory activities. Molecular docking studies showing significantly greater inhibition constant (Ki) 8.24 nM and binding energy (-11.03 kcal/mol) of pharachromenone than the standard ibuprofen (Ki 4.65 μM, binding energy -7.27 kcal/mol) at the binding site of 5-lipoxygenase recognized its noncompetitive binding, which could describe the promising anti-inflammatory potential. Pharachromenone could be developed as a functional food component against oxidative stress-related inflammatory disorders. PRACTICAL APPLICATIONS: The cuttlefish Sepia pharaonis (family Sepiidae) comprises a major share in the global fishery sector due to its culinary delicacy and nutritionally valued high-quality meat. Furthermore, cephalopod mollusks are gaining pharmaceutical acceptance as resources to derive bioactive compounds with therapeutic significance. Bioassay-guided chromatographic fractionation of crude extract of S. pharaonis could result in the isolation of a 2H-benzochromenone derivative, pharachromenone exhibiting potent antioxidant and anti-inflammatory properties. This study recognized the therapeutic potential of a marine cuttlefish-originated food constituent against inflammatory conditions, and could be anticipated as a high-value functional food lead to minimize oxidative stress-related inflammatory disorders.

Indole derivatives as tubulin polymerization inhibitors for the development of promising anticancer agents

The α- and β-tubulins are the major polypeptide components of microtubules (MTs), which are attractive targets for anticancer drug development. Indole derivatives display a variety of biological activities including antitumor activity. In recent years, a great number of indole derivatives as tubulin polymerization inhibitors have sprung up, which encourages medicinal chemists to pursue promising inhibitors with improved antitumor activities, excellent physicochemical, pharmacokinetic and pharmacodynamic properties. In this review, the recent progress from 2010 to present in the development of indole derivatives as tubulin polymerization inhibitors was summarized and reviewed, which would provide useful clues and inspirations for further design of outstanding tubulin polymerization inhibitors.

Green and Mechanochemical One-Pot Multicomponent Synthesis of Bioactive 2-amino-4H-benzo[b]pyrans via Highly Efficient Amine-Functionalized SiO2@Fe3O4 Nanoparticles

An ecofriendly, magnetically retrievable amine-functionalized SiO2@Fe3O4 catalyst was successfully synthesized and affirmed by several physicochemical characterization tools, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), energy-dispersive X-ray spectroscopy (EDX), and powder X-ray diffraction. Thereafter, the catalytic performance of this environmentally benign NH2@SiO2@Fe3O4 catalyst was investigated in the one-pot multicomponent synthesis of 2-amino-4H-benzo[b]pyran derivatives. The reaction was simply achieved by grinding of various substituted aromatic aldehydes, dimedone, and malononitrile at room temperature under solvent and waste-free conditions with excellent yields and high purity. Moreover, the developed catalyst not only possesses immense potential to accelerate the synthesis of bioactive pyran derivatives but also exhibits several remarkable attributes like broad functional group tolerance, durability, improved yield, reusability, and recyclability. Besides, various other fascinating advantages of this protocol are milder reaction conditions, cost effectiveness, short reaction time, and simple work up procedures.

Synthesis, Antimicrobial and Antitumor Evaluations of a New Class of Thiazoles Substituted on the Chromene Scaffold

BACKGROUND & OBJECTIVE

A new series of thiazoles substituted on the chromene scaffold were prepared by facial approaches starting from (E)-1-(2,3-Dihydrochromen-4-ylidene)thiosemicarbazide derivatives (2a,b). The thiosemicarbazides (2a,b) were reacted with a series of α-halo carbonyl compounds to give the corresponding rhodanine analogues and reacted also with C-acetyl-or Cethoxy- N-hydrazonoyl chlorides to afford the corresponding tri- and tetra-substituted hybrid hydrazinyl thiazole substituted chromenes.

METHODS

The newly synthesized compounds were screened for their in vitro antimicrobial and antitumor activities by agar diffusion method and MTT assay, respectively.

RESULTS

The results of the antimicrobial activity revealed that some of the new compounds exhibited excellent activity against pathogenic microorganism; Candida albicans compared with Ciprofloxacin and nystatin, as the reference drugs. All of the tested compounds exhibited significant cytotoxic activities comparable to that of the reference drug; Doxorubicin® (on HCT116 (colorectal carcinoma human cell line).

Evaluation of Pyrano[3,2 C] Quinoline Analogues as Anticancer Agents

Background:

Quinoline analogues exhibited diversified biological activities depending on the structure type. A number of natural products with pyrano[3,2-c]quinolone structural motifs and patented chromenes were reported as promising cytotoxic agents.

Objective:

The present study is aimed to evaluate a new series of pyrano[3,2-c]quinoline scaffolds derived from the fusion of bioactive quinolone pharmacophore with structurally diverse aryl substituted chromene for its cytotoxicity.

Methods:

A library of pyrano[3,2-c]quinoline analogues was prepared from one-pot multi component synthesis using various aromatic aldehydes, malononitrile and 2,4-dihydroxy-1-methylquinoline. The new synthetics were primarily screened for its cytotoxicity (IC50) against different human cancer cell lines in vitro. The promising synthetics were further evaluated in vitro for their potency against different kinase activity. The promising compounds were finally tested for their in vivo efficacy in SCID type mice HCT-116 tumor model.

Results:

The screening results revealed that compounds 4c, 4f, 4i and 4j showed promising activity in in vitro study. However, compound 4c was found to be the most potent candidate with 23% tumor growth inhibition in HCT-116 tumor mice model.

Conclusion:

The structure activity relationship suggested that 3-substitution on the aryl ring at C4 position of the pyrano[3,2 c]quinolone moiety seems to have an important position for cytotoxicity activity. However, 3- chloro substitution at C4 aryl ring showed a significant alteration of the bioactive conformer of the parent scaffold and outcome with compound 4c as the most potent candidate of the series.

The chromene derivative 4-Clpgc inhibits cell proliferation and induces apoptosis in the K562 cell line

Chronic myeloid leukemia (CML) is a malignant blood disease with a particular chromosomal aberration that is known as a common form of leukemia. The chromene family exhibits strong anti-cancer effects. Therefore, the effects of six members of the dihydropyrano [2,3-g] chromene family on cell toxicity and apoptosis induction in K562 cancer cells were investigated and compared with those of normal peripheral blood mononuclear cells (PBMCs). The K562 cells were cultured in the presence of the aforementioned chromene derivatives at concentrations of 40 to 200 μM for 24 to 72 h. The effects of these compounds on the growth and viability of the K562 cell line and PBMCs were studied through MTT assay. Furthermore, apoptosis induction was investigated using flow cytometry. Real-time PCR was used for relative quantification of BCL2, Bax, TP53 and BCR- ABL genes after 48 h of exposing K562 cells and PBMCs to 4-Clpgc. Based on the results, these chromene derivatives inhibited the growth of K562 cells. According to the obtained data, 4-Clpgc was the strongest compound with IC50 values of 102 ± 1.6 μM and 143 ± 9.41 μM in K562 cells and PBMCs, while pgc was the weakest one with IC50 levels of 278 ± 2.7 μM and 366 ± 47 μM in K562 cells and PBMCs (after 72 h), respectively. The results demonstrated that the apoptotic cell percentage in the control group increased from 6.09% to 84.10% and 17.2% to 20.06% in K562 cells and PBMCs after 48 h of treatment, respectively. Moreover, 4-Clpgc treatment increased the expression of Bax and TP53 genes by 42.74 and 35.88 folds in K562 cells and 9.60 and 7.75 folds in PBMCs, respectively. On the other hand, the expression of BCL2 was reduced by 1.47 and 1.38 folds in K562 cells and PBMCs, respectively. These compounds were associated with less toxic effects on normal cells, compared to the cancer cells. In conclusion, these derivatives can be considered as appropriate candidates for leukemia treatment.

Lemon juice catalyzed C-C bond formation via C-H activation of methylarene: a sustainable synthesis of chromenopyrimidines

An economical and proficient approach has been developed for the synthesis of chromenopyrimidines via three-component reaction of thiobarbituric acid/barbituric acid, methylarenes and dimedone/1,3-cyclohexanedione by using lemon juice as a natural, biodegradable catalyst and TBHP as an oxidant. This transformation involves metal-free C-C bond formation via C-H activation of methylarenes under mild reaction conditions.

Profiling the Stromal and Vascular Heterogeneity in Patient-derived Xenograft Models of Head and Neck Cancer: Impact on Therapeutic Response

Head and neck squamous cell carcinomas (HNSCC) represent a group of epithelial neoplasms that exhibit considerable heterogeneity in clinical behavior. Here, we examined the stromal and vascular heterogeneity in a panel of patient-derived xenograft (PDX) models of HNSCC and the impact on therapeutic response. Tumor sections from established tumors were stained for p16 (surrogate for human papillomavirus (HPV) infection), stromal (Masson’s trichrome) and vascular (CD31) markers. All PDX models retained the HPV/p16 status of the original patient tumor. Immunohistochemical evaluation revealed the presence of multiple vessel phenotypes (tumor, stromal or mixed) in the PDX panel. Vascular phenotypes identified in the PDX models were validated in a tissue microarray of human HNSCC. Treatment with a microtubule targeted vascular disrupting agent (VDA) resulted in a heterogeneous antivascular and antitumor response in PDX models. The PDX with the tumor vessel phenotype that exhibited higher CD31+ vessel counts and leaky vasculature on magnetic resonance imaging (MRI) was sensitive to VDA treatment while the PDX with the stromal vessel phenotype was resistant to therapy. Collectively, our results demonstrate the phenotypic and functional vascular heterogeneity in HNSCC and highlight the impact of this heterogeneity on response to antivascular therapy in PDX models of HNSCC.

Cesium-Carbonate-Mediated Benzalation of Substituted 2-Aryl-3-nitro-2 H-chromenes with Substituted 4-Benzylidene-2-phenyloxazol-5(4 H)-ones

Cs₂CO₃-mediated domino benzalation reaction with a variety of 2-aryl-3-nitro-2 H-chromenes and 4-benzylidene-2-phenyloxazol-5(4 H)-ones has been realized. The reaction proceeds smoothly with a broad substrate scope, thus providing a variety of substituted ( Z)-4-(( Z)-benzylidene)chroman-3-one oximes in moderate to high yields, which were easily transformed into biologically important 4 H-chromeno[3,4- c]isoxazoles.