The anti-rheumatic potential of a series of 2,4-di-substituted-4H-naphtho[1,2-b]pyran-3-carbonitriles

Controlled Modification of Triaminoguanidine-Based μ3 Ligands in Multinuclear [VIVO]/[VVO2] Complexes and Their Catalytic Potential in the Synthesis of 2-Amino-3-cyano-4H-pyrans/4H-chromenes

Reaction of tris(2-hydroxybenzylidene)-triaminoguanidinium chloride (I·HCl) and tris(5-bromo-2-hydroxybenzylidene)-triaminoguanidinium chloride (II·HCl) with [VIVO(acac)2] (1:1 molar ratio) in refluxing methanol resulted in mononuclear [VIVO] complexes, [VIVO(H2L1')(MeOH)] (1) and [VIVO(H2L2')(MeOH)] (2), respectively, where I and II undergo intramolecular triazole ring formation. Aerial oxidation of 1 and 2 in MeOH in the presence of Cs2CO3 gave corresponding cis-[VVO2] complexes Cs[(VO2)(H2L1')] (3) and Cs[(VO2)(H2L2')] (4). However, reaction of an aerially oxidized methanolic solution of [VIVO(acac)2] with I·HCl and II·HCl in the presence of Cs2CO3 (in 1:1:1 molar ratio) gave mononuclear complexes Cs[(VO2)(H3L1)] (5) and Cs[(VO2)(H3L2)] (6) without intramolecular triazole ring formation. Similar anionic trinuclear complexes Cs2[(VO2)3(L1)] (7) and Cs2[(VO2)3(L2)] (8) were isolable upon increasing the amounts of the vanadium precursor and Cs2CO3 to 3 equiv to the reaction applied for 5 and 6. Keeping the reaction mixture of 1 in MeOH under air gave [VVO(H2L1')(OMe)] (9). Structures of 3, 7, 8, and 9 were confirmed by X-ray crystal structure study. A permanent porosity in the crystalline metal-organic framework of 7 confirmed by single-crystal X-ray investigation was further verified by the BET study. Along with a suitable reaction mechanism, these synthesized compounds were explored as effective catalysts for the synthesis of biomolecules 4H-pyran/4H-chromenes.

Discovery of benzochromene derivatives first example with dual cytotoxic activity against the resistant cancer cell MCF-7/ADR and inhibitory effect of the P-glycoprotein expression levels

A series of 1H-benzo[f]chromene moieties (4a-z) were synthesised under Ultrasonic irradiation and confirmed with spectral analyses. Derivative 4i solely possessed an X-ray single crystal. The anti-proliferative efficacy of the desired molecules has been explored against three cancer cells: MCF-7, HCT-116, and HepG-2 with the cytotoxically active derivatives screened against MCF-7/ADR and normal cells HFL-1 and WI-38. Furthermore, compounds 4b-d, 4k, 4n, 4q, and 4w, which possessed good potency against MCF-7/ADR, were tested as permeability glycoprotein (P-glycoprotein [P-gp]) expression inhibitors. The attained data confirmed that 4b-d, 4q, and 4w exhibited strong expression inhibition against the P-gp alongside its cytotoxic effect on MCF-7/ADR. The western blot results and Rho123 accumulation assays showed that compounds 4b-d, 4q, and 4w effectively inhibited the P-gp expression and efflux function. Meanwhile, 4b-d, 4q, and 4w induced apoptosis and accumulation of the treated MCF-7/ADR cells in the G1 phase and 4k and 4n in the S phase of the cell cycle.

Tetrahydrobenzo[h]quinoline derivatives as a novel chemotype for dual antileishmanial-antimalarial activity graced with antitubercular activity: Design, synthesis and biological evaluation

Derivatives with tetrahydrobenzo[h]quinoline chemotype were synthesized via one-pot reactions and evaluated for their antileishmanial, antimalarial and antitubercular activities. Based on a structure-guided approach, they were designed to possess antileishmanial activity through antifolate mechanism, via targeting Leishmania major pteridine reductase 1 (Lm-PTR1). The in vitro antipromastigote and antiamastigote activity are promising for all candidates and superior to the reference miltefosine, in a low or sub micromolar range of activity. Their antifolate mechanism was confirmed via the ability of folic and folinic acids to reverse the antileishmanial activity of these compounds, comparably to Lm-PTR1 inhibitor trimethoprim. Molecular dynamics simulations confirmed a stable and high potential binding of the most active candidates against leishmanial PTR1. For the antimalarial activity, most of the compounds exhibited promising antiplasmodial effect against P. berghei with suppression percentage of up to 97.78%. The most active compounds were further screened in vitro against the chloroquine resistant strain P. falciparum, (RKL9) and showed IC50 value range of 0.0198-0.096 μM, compared to IC50 value of 0.19420 μM for chloroquine sulphate. Molecular docking of the most active compounds against the wild-type and quadruple mutant pf DHFR-TS structures rationalized the in vitro antimalarial activity. Some candidates showed good antitubercular activity against sensitive Mycobacterium tuberculosis in a low micromolar range of MIC, compared to 0.875 μM of isoniazid. The top active ones were further tested against a multidrug-resistant strain (MDR) and extensively drug-resistant strain (XDR) of Mycobacterium tuberculosis. Interestingly, the in vitro cytotoxicity test of the best candidates displayed high selectivity indices emphasizing their safety on mammalian cells. Generally, this work introduces a fruitful matrix for new dual acting antileishmanial-antimalarial chemotype graced with antitubercular activity. This would help in tackling drug-resistance issues in treating some Neglected Tropical Diseases.

A New Naphthopyran Derivative Combines c-Myb Inhibition, Microtubule-Targeting Effects, and Antiangiogenic Properties

Based on the promising c-Myb inhibitor 1b, a series of 2-amino-4-aryl-4H-naphtho[1,2-b]pyran-3-carbonitriles (1a, 2a-q, 3a-g) were repurposed or newly synthesized via a three-component reaction of 1-naphthol, and various aryl aldehydes and malononitrile and screened for their c-Myb inhibitory activities. 1b also served as a lead compound for seven new naphthopyran derivatives (3a-f), which were cytotoxic with nanomolar IC50 values, to inhibit the polymerization of tubulin, and to destabilize microtubules in living cells. Especially, the alkyne 3f, originally made for intracellular localization studies using click chemistry, showed an overall high activity in all assays performed. A strong G2/M cell cycle arrest was detected, which resulted in a distinct increase in sub-G1 cells through the induction of effector caspases 3 and 7. Inhibition of angiogenesis was confirmed in vitro and in vivo. In summary, 3f was found to be a pleiotropic compound with high selectivity for cancer cells, combining c-Myb inhibitory, microtubule destabilizing, and antiangiogenic effects.

Anticancer properties of arylchromenes and arylchromans: an overview

Cancers are a set of pathologies originated by cells that have the ability to divide and multiply uncontrollably, associated with the capacity to invade and colonize adjacent tissues. Chemotherapy is one of the main approaches of treatment for cancer patients. Despite of the numerous antineoplastic drugs available, cancer cannot be cured; particularly at the late stages deprived of any side effect. Arylchromenes and arylchromans are a group of small molecules, of natural or synthetic origin, of great interest as prototypes for the drug development, especially against cancer. In this chapter, we will present the antineoplastic activity studies of the most promising examples of these arylchromenes and arylchroman derivatives.

Para toluenesulfonic acid-catalyzed one-pot, three-component synthesis of benzo[5,6]chromeno[3,2-c]quinoline compounds in aqueous medium

A new series of benzo[5,6]chromeno[3,2-c]quinoline derivatives were successfully synthesized using various arylglyoxal monohydrates, quinoline-2,4-dione, and β-naphthol in H2O:EtOH (2:1) as a green solvent in the presence of catalytic amounts p-toluenesulfonic acid as a mild catalyst under reflux conditions with high yields (83–92%). The reaction conditions were optimized in different solvents at variable thermal conditions, and the optimized reaction condition for this synthesis has been reported. The structures of all new products were defined by 1H-NMR, 13C-NMR, FT-IR, mass spectral data, and HRMS.

Design of a Schiff Base Complex of Copper Coated on Epoxy-Modified Core-Shell MNPs as an Environmentally Friendly and Novel Catalyst for the One-Pot Synthesis of Various Chromene-Annulated Heterocycles

An ecofriendly inorganic-organic hybrid and novel Schiff base complex of copper coated on epoxy-modified Fe3O4@SiO2 MNPs was successfully designed and prepared from readily available chemicals. In this method, a Schiff base complex as a linker is utilized to protect copper nanoparticles to the core-shell Fe3O4 exterior without agglomeration. The resulted Schiff base complex of copper coated on epoxy-modified Fe3O4@SiO2 MNPs was characterized and confirmed via different analyses such as FT-IR, TGA, XRD, VSM, FE-SEM, TEM, ICP, EDX, and BET. The novel catalyst was examined for the synthesis of various chromene-annulated heterocycles through the one-pot three component reaction of aromatic aldehydes, various phenols (2-hydroxynaphthalene-1,4-dione/resorcinol/β-naphthol), and malononitrile in ethanol at reflux conditions. This method includes important aspects like no usage of column chromatography, very short reaction times, simplicity of product isolation using ethanol, excellent yields, simple procedures, and magnetic recoverability of the catalyst. All in all, our method makes a novel and significant advancement in the synthesis of various chromene-annulated heterocycles.

Novel biocompatible core/shell Fe3O4@NFC@Co(ii) as a new catalyst in a multicomponent reaction: an efficient and sustainable methodology and novel reusable material for one-pot synthesis of 4H-pyran and pyranopyrazole in aqueous media

Today, due to the developing need for inexpensive catalysts, recyclable magnetic nanocatalysts immobilized on polysaccharides possess many advantages over classical heterogeneous catalysts. However, cellulose has been an appealing material in catalysis science and technology. In this work, by controlling the interaction between the inorganic complexes and the support material, we designed a high activity nanostructured combination of a magnetic nanoparticle Fe3O4@NFC@Co(ii) terminated complex as a multi-nuclear catalyst. This protocol involves an environment friendly approach using cobalt acetate. The magnetic nanostructure Fe3O4@NFC@Co(ii) can be used as a novel, green, and a powerful catalyst that demonstrates a short reaction time, high yield and easy procedure for the cascade Knoevenagel-Michael-cyclocondensation reaction for the one-pot synthesis of 4H-pyrans and pyranopyrazoles. The superparamagnetic nanocomposite could be conveniently separated by using an external magnet. Moreover, the catalyst could be reused at least five times in new reaction runs without a noticeable loss of activity. The prepared catalyst was characterized by FT-IR, XRD, VSM, FESEM, EDAX, TEM, ICP, and TGA techniques. The experiments were achieved with good yields and implied that the catalytic method was effective and convenient for heterocyclic synthesis.

Ultrasound-assisted multicomponent synthesis of 4H-pyrans in water and DNA binding studies

A simple approach to synthesize new highly substituted 4H-pyran derivatives is described. Efficient Et3N acts as a readily accessible catalyst of this process performed in pure water and with only a 20 mol% of catalyst loading. The extremely simple operational methodology, short reaction times, clean procedure and excellent product yields render this new approach extremely appealing for the synthesis of 4H-pyrans, as potentially biological scaffolds. Additionally, DNA interaction analysis reveals that 4H-pyran derivatives behave preferably as minor groove binders over major groove or intercalators. Therefore, this is one of the scarce examples where pyrans have resulted to be interesting DNA binders with high binding constants (Kb ranges from 1.53 × 104 M-1 to 2.05 × 106 M-1).

Design and Synthesis of Novel Heterocyclic-Based 4H-benzo[h]chromene Moieties: Targeting Antitumor Caspase 3/7 Activities and Cell Cycle Analysis

Novel fused chromenes (4,7–11) and pyrimidines (12–16) were designed, synthesized, and evaluated for their mammary gland breast cancer (MCF-7), human colon cancer (HCT-116), and liver cancer (HepG-2) activities. The structural identity of the synthesized compounds was established according to their spectroscopic analysis, such as FT-IR, NMR, and mass spectroscopy. The preliminary results of the bioassay disclosed that some of the target compounds were proven to have a significant antiproliferative effect against the three cell lines, as compared to Doxorubicin, Vinblastine, and Colchicine, used as reference drugs. Particularly, compounds 7 and 14 exerted promising anticancer activity towards all cell lines and were chosen for further studies, such as cell cycle analysis, cell apoptosis, caspase 3/7 activity, DNA fragmentation, cell invasion, and migration. We found that these potent cytotoxic compounds induced cell cycle arrest at the S and G2/M phases, prompting apoptosis. Furthermore, these compounds significantly inhibit the invasion and migration of the different tested cancer cells. The structure-activity relationship (SAR) survey highlights that the antitumor activity of the desired compounds was affected by the hydrophobic or hydrophilic nature of the substituent at different positions.

New naphthopyran analogues of LY290181 as potential tumor vascular-disrupting agents

A series of 19 analogues of the antiproliferative naphthopyran LY290181 were prepared for structure-activity relationship studies. We found the best activities for test compounds bearing small substituents at the meta position of the phenyl ring. The mode of action of LY290181 and eight new analogues was studied in detail. The compounds were highly anti-proliferative with IC₅₀ values in the sub-nanomolar to triple-digit nanomolar range. The new analogues led to G2/M arrest due to interruption of the microtubule dynamics. In 518A2 melanoma cells they caused a mitotic catastrophe which eventually led to apoptosis. The naphthopyrans also induced a disruption of the vasculature in the chorioallantoic membrane (CAM) of fertilized chicken eggs as well as in xenograft tumors in mice. In a preliminary therapy trial, the difluoro derivative 2b retarded the growth of resistant xenograft tumors in mice.

1,2-Benzoxathiin-4(3H)-one 2,2-dioxide - new enol nucleophile in three-component interaction with benzaldehydes and active methylene nitriles

The reactivity of 1,2-benzoxathiin-4(3H)-one 2,2-dioxide was studied in multicomponent type reactions for the first time, namely, in a three-component interaction with active methylene nitriles and aromatic aldehydes in order to construct condensed 2-amino-4H-pyran derivatives. The reaction outcome strongly depended on the nature of an active methylene nitrile and an arenecarbaldehyde. Application of malononitrile resulted in novel 2-amino-4-aryl-4H-pyrano[3,2-c][1,2]benzoxathiine-3-carbonitrile 5,5-dioxides in most cases, whereas the utilization of ethyl cyanoacetate resulted in a complex mixture of products. In the last case, three different products were isolated depending on the arenecarbaldehyde used, namely ethyl 2-amino-4-aryl-4H-pyrano[3,2-c][1,2]benzoxathiine-3-carboxylate 5,5-dioxides, ethyl 2-cyano-3-arylacrylates, and salts of 3,3′-(arylmethylene)bis(4-hydroxybenzo[e][1,2]oxathiine 2,2-dioxides). Attempts to obtain separately ethyl 2-amino-4-aryl-4H-pyrano[3,2-c][1,2]benzoxathiine-3-carboxylate 5,5-dioxides enabled us to propose reaction pathways leading to these products. The salts were obtained for the first time. The preparative method for the synthesis of triethylammonium salts of 3,3′-(arylmethylene)bis(4-hydroxybenzo[e][1,2]oxathiine 2,2-dioxides) was proposed by the direct interaction of 1,2-benzoxathiin-4(3H)-one 2,2-dioxide with arenecarbaldehydes. The application of ammonium acetate as a catalyst allowed us to synthesize 7-aryl-7,14-dihydrobenzo[5,6][1,2]oxathiino[4,3-b]benzo[5,6][1,2]oxathiino[3,4-e]pyridine 6,6,8,8-tetraoxides containing a novel heterocyclic system. These facts, combined with our past investigations, allowed us to assert that the reactivity of enol nucleophiles that include the COCH₂SO₂X fragment has not been reported previously.

Reactivity of 1,2-benzoxathiin-4(3H)-one 2,2-dioxide was for the first time studied in multicomponent type reactions involving active methylene nitriles and aromatic aldehydes.

Introducing novel potent anticancer agents of 1H-benzo[f]chromene scaffolds, targeting c-Src kinase enzyme with MDA-MB-231 cell line anti-invasion effect

In our effort to develop novel and powerful agents with anti-proliferative activity, two new series of 1H-benzo[f]chromene derivatives, 4a–h and 6a–h, were synthesised using heterocyclocondensation methodologies under microwave irradiation condition. The structures of the target compounds were established on the basis of their spectral data, IR, ¹H NMR, ¹³ C NMR, ¹³ C NMR-DEPT/APT, and MS data. The new compounds have been examined for their anti-proliferative activity against three cancer cell lines, MCF-7, HCT-116, and HepG-2. Vinblastine and Doxorubicin have been used as positive controls in the viability assay. The obtained results confirmed that most of the tested molecules revealed strong and selective cytotoxic activity against the three cancer cell lines. Moreover, these molecules exhibited weak cytotoxicity on the HFL-1 line, which suggested that they might be ideal anticancer candidates. The SAR study of the new benzochromene compounds verified that the substituents on the phenyl ring of 1H-benzo[f]chromene nucleus, accompanied with the presence of bromine atom or methoxy group at the 8-position, increases the ability of these molecules against the different cell lines. Due to their high anti-proliferative activity, compounds 4c and 6e were selected to be examined their proficiency to inhibit the invasiveness of the highly sensitive and invasive breast cancer cell line, MDA-MB-231. The anti-invasion behaviour of these molecules against the highly sensitive, non-oestrogen, and progesterone MDA-MB-231 cell line gave rise to their decreasing metastatic effect compared to the reference drug. Furthermore, this report explores the apoptotic mechanistic pathway of the cytotoxicity of the target compounds and reveals that most of these compounds enhance the Caspase 3/7 activity that could be considered as potential anticancer agents.

Crystal structure of 3-amino-1-(4-bromophenyl)-9-methoxy-1H-benzo[f]chromene-2-carbonitrile, C21H15BrN2O2

C21H15BrN2O2, triclinic, P1̅ (no. 2), a = 8.6873(3) Å, b = 9.9252(3) Å, c = 11.0013(3) Å, α = 77.977(2)°, β = 70.989(2)°, γ = 89.321(2)°, V = 875.55(5) Å3, Z = 2, Rgt(F) = 0.0369, wRref(F2) = 0.1043, T = 296(2) K.

Design of New Benzo[h]chromene Derivatives: Antitumor Activities and Structure-Activity Relationships of the 2,3-Positions and Fused Rings at the 2,3-Positions

A series of novel 4H-benzo[h]chromenes 4, 6-11, 13, 14; 7H-benzo[h]chromeno[2,3-d]pyrimidines 15-18, 20, and 14H-benzo[h]chromeno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives 19a-e, 24 was prepared. The structures of the synthesized compounds were characterized on the basis of their spectral data. Some of the target compounds were examined for their antiproliferative activity against three cell lines; breast carcinoma (MCF-7), human colon carcinoma (HCT-116) and hepatocellular carcinoma (HepG-2). The cytotoxic behavior has been tested using MTT assay and the inhibitory activity was referenced to three standard anticancer drugs: vinblastine, colchicine and doxorubicin. The bioassays demonstrated that some of the new compounds exerted remarkable inhibitory effects as compared to the standard drugs on the growth of the three tested human tumor cell lines. The structure-activity relationships (SAR) study highlights that the antitumor activity of the target compounds was significantly affected by the lipophilicity of the substituent at 2- or 3- and fused rings at the 2,3-positions.

Synthesis, in-vitro cytotoxicity of 1H-benzo[f]chromene derivatives and structure–activity relationships of the 1-aryl group and 9-position

A series of 1H-benzo[f]chromene-2-carbonitriles was synthesized and evaluated for their cytotoxic activities against MCF-7, HCT-116, and HepG-2 cancer cells. The SAR studies reported that the substitution in the phenyl ring at 1-position of 1H-benzo[f]chromene nucleus with the specific group, H atom, or methoxy group at 9-position increases the ability of the molecule against the different cell lines.

Peculiarities of 2-amino-3-R-4-aryl-4H-pyranes multicomponent synthesis derived from 1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide

The new 2-amino-3-R-4-aryl-6-ethyl-4,6-dihydropyrano[3,2-c][2,1] benzothiazine 5,5-dioxides were synthesized via three-component interaction of 1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide with arylcarbaldehydes and active methylene nitriles.