Search

Upon reaction with α,β‐unsaturated nitriles (2 a–d) and/or salicylaldehyde, 3‐(naphthalen‐2‐yl)‐3‐oxopropanenitrile (1) yields pyridine derivatives 3 a–d and/or the imino chromene derivative 4. Compound 1 reacted with phenyl isothiocyanate in a basic medium to give the intermediate potassium salt 6. Upon stirring at room temperature, the intermediate 6 with some α‐halogenated compounds yielded the acyclic compounds 7, 9, 11, 13, and 15. On the other hand, refluxing intermediate 6 with the same α‐halogenated compounds in DMF in the presence of TEA afforded the corresponding thiophene derivatives 8, 10, 12, 14, and 16. The reaction of thiol 17 with hydrazine hydrate derivatives 18 a–d yielded the corresponding pyrazole derivatives 21 a–d. Compound 20 reacted with o‐phenylenediamine or o‐aminothiophenol in the presence of DMF/TEA to give the corresponding benzothiazole or benzoimidazole derivatives 27 a and 27 b, respectively. Thirty new synthesized compounds were examined for their antibacterial activity against Gram‐positive bacteria including S. aureus and B. subtilis, Gram‐negative bacteria such as P. aeruginosa and E. coli, and yeast‐like fungi like C. albicans in vitro. Compounds 15, 16, 21 d, 27 a, 27 b, exhibited the highest antibacterial activity against Gram‐positive bacteria. Molecular docking experiments were conducted to explore the binding affinities and interaction modalities of selected derivatives with the target PDB‐3cmt protein. [ABSTRACT FROM AUTHOR]

To discover new and highly effective herbicidal compounds, 29 (Z)-N-(2,6-dioxo-5-phenyl- 1,2,3,5,6,7,8,9-octahydro-4H-chromeno[2.3-d]pyrimidin-4-ylidene)-4-methylbenzenesulfonamide derivatives (VIaa-VIbe) were designed and synthesized. The structures of these compounds were characterized by melting point, ¹H NMR, 13C NMR, and HRMS. The spatial configuration of compound VIan was determined using X-ray single crystal diffraction. The herbicidal activity of these compounds was tested using the plate method with barnyard grass and piemarker as target weeds. The target compounds exhibited inhibition rates of over 70% against barnyard grass, with compound VIak showing 85% inhibition at a concentration of 200 mg/L, but the inhibitory effect on the piemarker was slightly lower. The inhibitory medium concentration (IC50) of compound VIak on seed germination of barnyard grass was 113 mg/L. Crop safety experiments showed that compound VIak at a dosage of 500 or 1000 mg/L caused varying degrees of phytotoxicity to maize, rice, and rapeseed. However, the phytotoxicity to soybean was the lowest among these crops and significantly lower than the control herbicide bensulfuronmethyl pretilachlor. Transmission electron microscopy showed that the chloroplasts of barnyard grass were broken and dispersed, most chloroplast envelope changed from elongated to oval, osmophilic particles appeared in the chloroplast, the lamella of the inner capsule disappeared, and the matrix stack was scattered, including a large number of large vesicles when barnyard grass seeds were treated with compound VIak. The enzyme activity assay showed that compound VIak at 50-450 mg/L showed a trend of slow increase to CAT acitivity and H2O2 content at first and then stable. It can be concluded that compound Vlak may inhibit the growth of barnyard grass by destroying chloroplast structure and affecting CAT activity and H2O2 content, thus providing lead compounds for the development of barnyard grass. [ABSTRACT FROM AUTHOR]

Abstract A series of benzoquinoline-employing heterocycles was synthesized by treating 3-chlorobenzo[f]quinoline-2-carbaldehyde with N-phenyl-3-methylpyrazolone, 4-aminoacetophenone, 1,2-diaminoethane, and 2-cyanoethanohydrazide. Also, pyridine, chromene, α,β-unsaturated nitrile, thiosemicarbazone, and 1,2-bis-aryl hydrazine derivatives were prepared from the cyanoethanohydrazone obtained. The DFT calculations and experiment outcomes were consistent. In vitro screening of their antiproliferative efficacy was examined against HCT116 and MCF7 cancer cell lines. The pyrazolone 2 and cyanoethanohydrazone 5 derivatives exhibited the most potency, which was demonstrated by their molecular docking towards the CDK-5 enzyme. The binding energies of compounds 2 and 5 were − 6.6320 kcal/mol (with RMSD of 0.9477 Å) and − 6.5696 kcal/mol (with RMSD of 1.4889 Å), respectively, which were near to that of co-crystallized ligand (EFP). This implies a notably strong binding affinity towards the CDK-5 enzyme. Thus, pyrazolone derivative 2 would be considered a promising candidate for further optimization to develop new chemotherapeutic agents. In addition, the ADME (absorption, distribution, metabolism, and excretion) analyses displayed its desirable drug-likeness and oral bioavailability properties.

Alzheimer's Disease (AD) is one of the most devastating chronic health problems of the last few decades. Unfortunately, current treatment and care options for AD are insufficient, making it a prominent topic for drug discovery studies. Currently, AD drug development studies have focused on the strategy of multitarget directed ligands (MTDLs). Following this strategy, we designed new ChE inhibitors with additional antioxidant and metal chelator effects. In this research, we designed and synthesized novel eight N'-(4-oxo-4H-chromen-3-yl)methylene propanehydrazide derivatives. We then evaluated the inhibition potency of all final compounds for cholinesterase enzymes. Among them, (6f) (IC50 AChE=16.91 µM) was found to be the most potent acetylcholinesterase inhibitor. Additionally, (6d) (IC50's AChE=26.91 µM and BChE=47.94 µM) exhibited dual cholinesterase inhibitor activity. Moreover, we investigated all title compounds for their antioxidant (DPPH, ORAC) and metal chelator activities. According to the ORAC-FL results, all the compounds exhibited good antioxidant activity ranging from 4.082 to 16.715 Trolox equivalents. We also observed chelator effects of all compounds for Cu(II), Fe(II), and Zn(II) ions at varying rates. Furthermore, we assessed the in-silico physicochemical parameters of the compounds to evaluate their drug-likeness or druggability. [ABSTRACT FROM AUTHOR]

This study presents the synthesis and characterization of a new, recyclable, and thermally stable heterogeneous catalyst for the efficient synthesis of polyhydroquinoline and chromene derivatives. The catalyst was characterized using various techniques, including UV spectroscopy, FT‐IR, TGA, DTG, SEM, XRD, ICP Spectroscopy, and CHN analysis. The successfully designed phthalocyanine incorporates both Brønsted and Lewis acid functionality, along with zwitterionic properties. It was effectively utilized in the synthesis of polyhydroquinoline and chromene derivatives. The methodology offers several advantages, such as a simple procedure, excellent yields, and a short reaction time. The findings from this research provide valuable insights into formulating and advancing new catalysts for significant organic reactions. [ABSTRACT FROM AUTHOR]

Phthalide, benzoxazole, and chromene are important heterocyclic skeletons with extensive biological activities. In order to develop novel potential antifungal agents, twenty-two benzoxazole/chromene-containing phthalide derivatives were prepared, and their fungicidal activity against nine common plants pathogenic fungi were evaluated in vitro. The EC50 values indicated that compound Z-4b displayed superior antifungal activity against P. oryzae (11.0 μg/mL), F. solani (8.5 μg/mL), P. capsici (27.8 μg/mL), V. mali (3.1 μg/mL) and A. brassicae (4.3 μg/mL) strains, which was more potent than the two commercialized fungicides hymexazol and chlorothalonil. In addition, the structure-activity relationship analysis demonstrated that the combination site of oxazolamide with phthalide has an important effect on antifungal activity. This research offers a potential compound for the development of novel agricultural fungicides. [ABSTRACT FROM AUTHOR]

A series of benzoquinoline-employing heterocycles was synthesized by treating 3-chlorobenzo[f]quinoline-2-carbaldehyde with N-phenyl-3-methylpyrazolone, 4-aminoacetophenone, 1,2-diaminoethane, and 2-cyanoethanohydrazide. Also, pyridine, chromene, α,β-unsaturated nitrile, thiosemicarbazone, and 1,2-bis-aryl hydrazine derivatives were prepared from the cyanoethanohydrazone obtained. The DFT calculations and experiment outcomes were consistent. In vitro screening of their antiproliferative efficacy was examined against HCT116 and MCF7 cancer cell lines. The pyrazolone 2 and cyanoethanohydrazone 5 derivatives exhibited the most potency, which was demonstrated by their molecular docking towards the CDK-5 enzyme. The binding energies of compounds 2 and 5 were − 6.6320 kcal/mol (with RMSD of 0.9477 Å) and − 6.5696 kcal/mol (with RMSD of 1.4889 Å), respectively, which were near to that of co-crystallized ligand (EFP). This implies a notably strong binding affinity towards the CDK-5 enzyme. Thus, pyrazolone derivative 2 would be considered a promising candidate for further optimization to develop new chemotherapeutic agents. In addition, the ADME (absorption, distribution, metabolism, and excretion) analyses displayed its desirable drug-likeness and oral bioavailability properties. [ABSTRACT FROM AUTHOR]

The chromenopyridine scaffold represents an important class of heterocyclic compounds exhibiting a broad spectrum of biological properties. This review describes novel and efficient procedures for the synthesis of this scaffold. Herein, several methods were detailed and grouped according to their starting material (e.g., salicylaldehydes, chromones, chromanones and coumarins) and respective biological activity, when reported. This review highlights the potential of the reported synthetic strategies for preparing chromenopyridine derivatives with promising biological activity, paving the way for further developments in drug discovery. [ABSTRACT FROM AUTHOR]

New nano‐sized Ni(II), Pd(II), and Pt(II) Schiff base chelates of 2‐(((Z)‐6‐chloro‐3‐((E)‐([2‐hydroxyphenyl]imino)methyl)‐4H‐chromen‐4‐ylidene)amino)phenol were designed and manufactured. The structural characterization of these isolated compounds was accomplished through spectral measurements, thermal and elemental analyses, and magnetic moment and conductivity determinations. The nano‐sized metal(II) complexes molar conductance indicated that they exhibited non‐electrolytic behavior. The UV–Vis spectral data and magnetic moment provided evidence for producing octahedral geometries in the nano‐sized complexes of Ni(II), Pd(II), and Pt(II). Metal chelates' thermal characteristics and decomposition kinetics were examined through Coats‐Redfern technique. The kinetic aspects, including pre‐exponential factor (A), the entropy of activation (ΔS), and activation energy (E) were enumerated. The X‐ray diffraction (XRD) calculations results of the trivalent metal complexes showed that sharp and intense diffraction peaks signify their crystalline properties with nanoscale particle size, and another proof was obtained from the images of SEM, TEM, EDX, and AFM also homogeneous distribution over the complex surface was confirmed. Molecular modeling techniques were adopted to optimize the metal complexes geometry. The viscosity and UV–Vis absorption determinations were utilized to assess the calf thymus DNA (CT‐DNA) interaction with the nano‐sized metal(II) chelates. The acquired data revealed that the complexes exhibit a non‐intercalative or incomplete binding pattern when interacting with DNA. The calculated DNA‐complexes binding constants are 3.93 ± 0.02 × 10,4 1.67 ± 0.3 × 105 and 2.88 ± 0.03 × 105 M−1, for nano‐sized Ni(II), Pd(II) and Pt(II) Schiff base chelates, successively. Both Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) and Gram‐positive (Bacillus subtilis and Streptococcus pneumoniae) micro‐organisms were tested against H2L Schiff base ligand and its nano‐sized metal(II) complexes. Candida albicans and Aspergillus fumigatus were tested for antifungal activity, revealing that most complexes had activity lower than H2L ligand, while the complex of Ni(II) exhibited no discernible antifungal activities. Furthermore, the manufactured complexes underwent testing for their in‐vitro anticancer and antibacterial effectiveness. Furthermore, the complexes antioxidant activity was appraised through DPPH and ABTS inhibition tests, revealing distinct scavenging abilities on DPPH radicals. The complexes were ordered according to their scavenging capacity as follows: Ni(II) complex > Pd(II) complex > Pt(II) complex. Finally, the study of cell cycle arrest by the Ni(II), Pd(II), and Pt(II) complexes on HEPG2 has also been performed through flow cell cytometry. [ABSTRACT FROM AUTHOR]

[Display omitted] • Probe COM-CH sensing ability towards Th4+ chromogenic and fluorogenic methods in ACN: H 2 O (8:2, v/v). • Probe COM-CH photophysical, solvatochromism, aggregation were studies by UV–Vis and fluorescence spectral studies. • Probe COM-CH form a 2:1 stoichiometry complex with Th4+ ions with an estimated binding constant of 1.92 × 108 M−2. • Probe COM-CH is used for the in-vivo bioimaging of Th4+ in Caenorhabditis elegans. The manuscript presents the synthesis of a new di-chromene Schiff base (COM-CH) by combining 7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide and 4-oxo-4H-chromene-3-carbaldehyde, and its characterization using various analytical techniques. The probe COM-CH functional group contains a hard donor atom that selectively complexes with Th4+ ions. This report investigated COM-CH 's sensing ability towards Th4+ chromogenic and fluorogenic methods in ACN: H 2 O (8:2, v/v) with Th4+ ions. The COM-CH-Th4+ complex was excited at 430 nm, resulting in a bright emission band at 475 nm with a 45 nm Stokes shift. The COM-CH probe demonstrated the highest performance at pH 4.0 to 8.0, with a sensitivity of 18.7 nM. The complex formation of COM-CH with Th4+ was investigated using NMR, FTIR spectrometry, and density functional theory calculations. The COM-CH and Th4+ are bound with 2:1 stoichiometry and an association constant of 1.92 × 108 M−2. The probe's performance enabled the analysis of monazite sand and water samples for Th4+ content. The probe successfully detected Th4+ content in Caenorhabditis elegans, marking the first Th4+ detection in animal models. [ABSTRACT FROM AUTHOR]

A novel ionic responsive Schiff base organic gelator was successfully designed and synthesized. The solvent selection experiment showed that the gelator showed good thermoreversible gelator behavior in aniline, valerate alcohol and isopropyl alcohol. FT-IR studies have shown that C=O and N–H of molecules participate in the formation of intermolecular hydrogen bonds, thus promoting the formation of gelator states. The XRD and SEM results show that the molecules self-assemble in the dry gelator to form the entangled network structure. In addition, the fluorescence spectrum test of gelling agent G showed that gelling agent G could specifically recognize Cu2+. Gelator G has good selectivity, low detection limit (2.92 × 10–8 M) and high sensitivity, which can be applied to the detection of Cu2+ in biology, environment and other fields. The results show that gelator G has broad application prospects in materials science, chemistry, biomedicine and other fields. It also confirms that benzopyran-derived hydrazone Schiff base compounds have far-reaching research significance. [ABSTRACT FROM AUTHOR]

A protocol for the synthesis of 3,4-dihydropyrano[c]chromenes (DHPCs) using tris(2-hydroxyethyl)ammonium lactate (THAL) as an ionic liquid (IL) and biodegradable catalyst has been developed. This method involves the reaction of aldehydes, malononitrile, and 4-hydroxycoumarin under solvent-free conditions at 80 °C. The efficiency of THAL as catalyst was evaluated by conducting a series of control experiments using dimedone, 2-hydroxynaphthalene-1,4-dione, and 1,3-dimethylbarbituric acid as substrates under optimized conditions. [ABSTRACT FROM AUTHOR]

In this research, a coated graphite polyvinyl chloride (PVC) membrane electrode was fabricated for the potentiometric determination of lithium based on 13-(3-nitrophenyl)-12H,14H-benzo[g]chromeno[2,3-b]chromene-7,12,14(13H)-trione (L) as the ionophore. The best Nernstian response was observed from the membrane composition of 31% PVC, 7% L, 2% NaTPB, and 60% dioctyl phthalate (DOP) as the plasticizer. The designed sensor showed a wide linearity over the concentration range of 1 x 10-8-1 x 10-3 M with a slope of 60.2 ± 0.3 mV decade-1, and the limit of detection (LOD) of 7.5 x 10-9 M. The selectivity of the designed sensor was investigated by the matched potential method and no serious interference was observed. The response time and life span of the electrode were 5 s and 16 weeks, respectively. The potential response of the electrode was independent of solution pH in the pH range of 3.0-12.0. The influence of the presence of organic solvents on the potential response of the electrode was also scrutinized, and the results showed that the designed sensor keeps its Nernstian behavior in solutions with 20% non-aqueous content. In the end, the electrode was successfully applied to determine lithium carbonate in tablet, urine, and serum samples with recovery% values of 96.0 to 106.33 and RSD% 1.99-4.45. [ABSTRACT FROM AUTHOR]

The 2-cyano-3-(indol-3-yl)acryloyl chloride, a building block synthon prepared in good yield, was utilized for the synthesis of various indolylacrylamide and indole-based heterocycles. Thus, the aforementioned acid chloride was allowed to react with various oxygen, sulfur, and nitrogen nucleophiles, in addition to mono- and bidentate nucleophiles. The pyrazolidine derivatives were produced on interactions with phenylhydrazine and 2-cyanoethanohydrazide. The antioxidant activity of the synthesized compounds was assessed using the phosphomolybdenum technique and ascorbic acid as a standard. The findings displayed that indolyl-based azine, pyrazolidine, cyanoacetamide, and benzodiazepine derivatives were the most active antioxidants. [ABSTRACT FROM AUTHOR]

New chromene derivatives were synthesized based on 4‐(3,4‐dimethoxy)‐4H‐chromene scaffold. All target compounds exhibited cytotoxic activity against HepG2 cells (IC50 = 2.40–141.22 μM). Chromens 5 and 9 showed superior cytotoxicity over staurosporine (IC50 = 18.27 μM) and vinblastine (IC50 = 5.20 μM). c‐Src kinase inhibition assay of compounds 5 and 9 displayed the dominant c‐Src inhibitory activity of 5 (IC50 = 0.184 μM) over 9 (IC50 = 0.288 μM). The safety of the most potent compound 5 against normal WI‐38 cells was confirmed via its IC50 of 115.75 μM comparable with 5‐FU (IC50 = 16.28 μM). Moreover, the promising chromene 5 displayed potent cytotoxicity against resistant HepG2 cells with IC50 of 26.03 μM comparable with 5‐FU (IC50 = 42.68 μM). The most active chromene 5 arrested the HepG2 cell cycle at the S phase and induced a 29‐fold increase in the total number of apoptotic cells indicating pre‐G1 apoptosis. The ability of compound 5 to induce apoptosis was supported via elevation of caspase‐3, caspase‐7, caspase‐9 and proapoptotic Bax protein levels in addition to downregulation of the antiapoptotic Bcl2 protein. Molecular docking studies of compound 5 showed good binding interaction pattern inside c‐Src kinase enzyme active site. [ABSTRACT FROM AUTHOR]

From an EtOAc-soluble fraction of the roots of Paramignya trimera, one undescribed chromene derivative, paratrimerin Z (1), was isolated. Its structure was elucidated on the basis of NMR spectroscopic interpretation. The absolute configuration of 1 was determined by the specific rotation analysis of its acid-catalyzed hydrolysis product. Paratrimerin Z (1), at a concentration of 100 μM, did not show cytotoxicity against Hep3B human liver cancer cell line. [ABSTRACT FROM AUTHOR]

In a one-pot tandem condensation reaction, three functional ionic liquids (ILs) derived from pyridinium were employed as green, reusable, and efficient catalysts for the synthesis of important medicinal chemistry derivatives such as 2-amino-4H-chromenes. Additionally, benzimidazoles and benzothiazoles were synthesized using these catalysts. The ILs were favored for their easy set-up, high yields, and short synthesis times for the desired products. Moreover, the ILs could be easily recovered and reuse multiple times without significant loss of catalytic activity. Characterization of the synthesized compound was achieved through FT-IR, 1H NMR, 13C NMR, TGA and melting point analysis. The compounds were prepared with good to excellent isolated yields under mild conditions, while the synthesis of benzimidazoles and benzothiazole derivatives was successful at both reflux and room temperature conditions. Finally, each class of compound was described along with its corresponding synthesis mechanism.

Exploration of artificial aggregation-induced emission luminogens (AIEgens) has garnered extensive interest in the past two decades. In particular, AIEgens possessing natural characteristics (BioAIEgens) have received more attention recently due to the advantages of biocompatibility, sustainability and renewability. However, the extremely limited number of BioAIEgens extracted from natural sources have retarded their development. Herein, a new class of BioAIEgens based on the natural scaffold of chromene have been facilely synthesized via green reactions in a water system. These compounds show regiostructure-, polymorphism- and substituent-dependent fluorescence, which clearly illustrates the close relationship between the macroscopic properties and hierarchical structure of aggregates. Due to the superior biocompatibility of the natural scaffold, chromene-based BioAIEgens can specifically target the endoplasmic reticulum (ER) via the introduction of tosyl amide. This work has provided a new chromene scaffold for functional BioAIEgens on the basis of green and sustainable 'in-water' synthesis, applicable regiostructure-dependent fluorescence, and effective ER-specific imaging. [ABSTRACT FROM AUTHOR]

In search of the better anticancer agents, a series of chromene-1,3,4-oxadiazole containing 1,2,3-triazole derivatives were synthesized using 6-fluoro-2-(5-(prop-2-yn-1-ylsulfonyl)-1,3,4-oxadiazol-2-yl)-4H-chromen-4-one and freshly prepared substituted aryl azides. The newly synthesized derivatives were evaluated for their in vitro cytotoxic activity against MCF-7 and A-549. Among all the synthesized compounds, 6-fluoro-2-(5-(((1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl)sulfonyl)-1,3,4-oxadiazol-2-yl)-4H-chromen-4-one and 2-(5-(((1-(3,5-dimethoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl)sulfonyl)-1,3,4-oxadiazol-2-yl)-6-fluoro-4H-chromen-4-one shows potent anticancer activity as compared to remaining derivatives. Similarly, the compounds 2-(5-(((1-(3,5-dimethoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl)sulfonyl)-1,3,4-oxadiazol-2-yl)-6-fluoro-4H-chromen-4-one and 2-(5-(((1-(3,5-dichlorophenyl)-1H-1,2,3-triazol-4-yl)methyl)sulfonyl)-1,3,4-oxadiazol-2-yl)-6-fluoro-4H-chromen-4-ones were found to be active against EGFR. [ABSTRACT FROM AUTHOR]

The potential of phosphites as nucleophiles for the asymmetric synthesis of chiral chromene derivatives has been overlooked in the literature. Herein, we report a promising approach via asymmetric organocatalyzed phospha‐Michael addition to iminochromenes, using a bifunctional squaramide, which gives access to chromenylphosphonates, an interesting family of bioactive compounds. Our optimized protocol provides very good reactivity, affording yields of up to 95% and with chiral products exhibiting an enantiomeric excess of up to 98%. [ABSTRACT FROM AUTHOR]

A one-pot protocol was developed to prepare new thiazol-2(3H)-imines in efficient yields. Therefore, the reaction of the appropriate aromatic amine, phenyl isothiocyanate and chloroacetone (ratio 1:1:1) was mediated using different solvents and bases. The optimized protocol was to conduct the reaction in ethanol at reflux in the presence of 1.2 equivalents of sodium acetate. The reaction produced the regioisomeric (Z)-N-aryl-3-phenylthiazol-2(3H)-imine, as detected by 1D and 2D NMR spectral data. Using a similar protocol, new arene- or chromene-linked thiazol-2(3H)-imines were prepared by the use of the respective α-bromoketones. The new products were screened against six different bacterial strains. In general, chromene-linked thiazol-2(3H)-imines displayed superior antibacterial activity over other products. Thiazol-2(3H)-imines linked to 6-methyl and 6-methoxy-2-oxo-2H-chromene units had the most effective antibacterial activity with MIC/MBC values of 2.0/4.0 and 1.9/3.9 µM, respectively, against Staphylococcus aureus, Streptococcus mutans, and Escherichia coli strains. [ABSTRACT FROM AUTHOR]

The title compound, C23H15BrN2OS, was the unexpected product in an attempted synthesis of the isomeric 3-(benzo[d]thiazol-2-yl)-6-bromo-1-p-tolylquinolin-2(1H)-one. The Cchromene=N—C angle is wide [125.28 (8)°]. The benzothiazole and chromene ring systems are almost coplanar, with their planes parallel to (1\overline{1}0); the toluene ring system is rotated by ca 40° out of the chromene plane. The molecular packing involves layers with π-stacking, borderline `weak' hydrogen bonds and possible C—H...π contacts.

The chromenopyridine scaffold represents an important class of heterocyclic compounds exhibiting a broad spectrum of biological properties. This review describes novel and efficient procedures for the synthesis of this scaffold. Herein, several methods were detailed and grouped according to their starting material (e.g., salicylaldehydes, chromones, chromanones and coumarins) and respective biological activity, when reported. This review highlights the potential of the reported synthetic strategies for preparing chromenopyridine derivatives with promising biological activity, paving the way for further developments in drug discovery.

An efficient process to access chromeno-fused azafluorenones (chromeno[2,3-b]indeno[2,1-e]pyridine) via the three-component reaction between 2-amino-4H-chromen-4-ones, aromatic aldehydes and 1H-indene-1,3(2H)-dione is described. This approach includes successive the Aldol condensation, the Michael addition, intramolecular nucleophilic addition and aromatization. The structure of a product obtained was determined based on X-ray diffraction studies. Chromeno[2,3-b]indeno[2,1-e]pyridine derivatives were synthesized effectively via a K2CO3-promoted three-component reaction of 2-amino-4H-chromen-4-ones, aromatic aldehydes and 1H-Indene-1,3(2H)-dione under mild conditions. [ABSTRACT FROM AUTHOR]

Inhibiting α‐glucosidase is a reliable method for reducing blood sugar levels in diabetic individuals. Several novel chromen‐linked hydrazine carbothioamide (3a–r) were designed and synthesized by condensation of chromone‐3‐carbaldehyde with a variety of substituted thiosemicarbazides. The structures of these new analogues were elucidated through various advanced spectroscopic techniques (1H NMR, 13C NMR, and ESI‐MS). The resulted compounds were screened for α‐glucosidase inhibitory potential and all the compounds (3a–r) exhibited potent inhibition of α‐glucosidase with IC50 values ranging 0.29–53.70 µM. Among them compounds 3c, 3f, 3h, and 3r displayed the highest α‐glucosidase inhibitor capability with IC50 values of 1.50, 1.28, 1.08, and 0.29 µM, respectively. Structure–activity relationship showed that different substituted groups are responsible for the variation in the α‐glucosidase inhibition. The kinetics studies of the most active inhibitor (3r) were performed, to investigate the mode of inhibition and dissociation constants (Ki), that indicated a competitive inhibitor with Ki value of 1.47 ± 0.31 µM. Furthermore, molecular docking studies was performed to reveal the possible interactions, such as H‐bonding, or π–π stacking, with the key residues of α‐glucosidase. Docking analysis revealed the importance of hydrazine carbothioamide moiety of compounds in the attachment of ligands with the crucial residues of α‐glucosidase. The estimated pharmacokinetic, physicochemical, and drug likeness properties of compounds 3a–r reflects that these molecules have acceptable range of these properties. [ABSTRACT FROM AUTHOR]

It was well known that hydrazine–hydrazone derivatives have an important role in different synthetic and medicinal fields. Therefore, the hydrazide–hydrazone derivative 3 was treated with electrophilic reagents achieving some quinoline-based heterocyclic systems such as chromene and pyridine derivatives and screened for their rodenticidal activity. The potent compounds were subjected to density functional theory studies. Seven compounds were tested for hemorrhoidal activity. Compounds 5, 6, and 7 were more effective against rodents than the other synthesized compounds, which were controlled by the most potent active second-generation products, such as chlorophacinone, brodifacoum, and warfarin. This could be attributed to their existence in more tautomeric structures. As a result, they could be used as rodenticides. [ABSTRACT FROM AUTHOR]

Novel heterocyclic compounds containing a benzothiazole moiety (2–16) were synthesized via the reaction of benzothiazole cyanoacetamide derivative (2) with different types of reagents. All compounds were characterized by 1H NMR, MS, and IR techniques. The newly synthesized compounds were examined for their in vitro antibacterial activity against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and fungi (Candida albicans) microorganisms. Compounds (5, 6, 7, and 15) are promising antimicrobial agents and could be the lead compounds for more potent drugs. Binding modes of the synthesized compounds were analyzed by docking studies that showed good binding scores against the diverse amino acids of the two selected proteins (PDB Codes – 2EXB and 3HUN). The conducted docking studies were found to be consistent with antimicrobial results. Thus, the results indicate that the designed structures can be a potential lead as antimicrobial agents. [ABSTRACT FROM AUTHOR]

The title compound, C23H15BrN2OS, was the unexpected product in an attempted synthesis of the isomeric 3-(benzo[d]thiazol-2-yl)-6-bromo-1-p-tolylquinolin-2(1H)-one. The Cchromene N-C angle is wide [125.28 (8)°]. The benzothiazole and chromene ring systems are almost coplanar, with their planes parallel to (110); the toluene ring system is rotated by ca 40° out of the chromene plane. The molecular packing involves layers with π-stacking, borderline 'weak' hydrogen bonds and possible C-H...π - contacts. [ABSTRACT FROM AUTHOR]

In the title co-crystal, C20H14N2O4·C2H4O2, the expected proton transfer from acetic acid to amine has not occurred. In the crystal, the chromene molecules are linked by N—H...O and N—H...N hydrogen bonds to generate [100] columns. The acetic acid molecules form inversion dimers linked by pairwise O—H...O hydrogen bonds and occupy voids between the columns.

2-Amino-4H-benzo[H]chromene-3-carbonitrile and 2-amino-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile are two important pharmacophores with extensive applications in medicinal chemistry. The multicomponent Knoevenagel–Michael reaction is one of the most efficient strategies to construct these two scaffolds. Previous efforts have been made in converting the traditional organic solvents to eco-friendly solvents including H2O generally in the presence of complex catalysts. Here we present our work of using sodium fluoride (NaF) as the catalyst to synthesize a wide scope of the two types of substrates starting from α- or β-naphthol or 4-hydroxycoumarin. Using 12 mol% NaF under the microwave irradiation condition, the reactions were completed within 15–25 min with all the yields exceeding 85%. The reaction products were purified simply by washing with H2O and can be further purified by crystallization with MeOH. The analysis of green chemistry-related parameters suggested that the current method was highly environmentally benign, highlighting the potential of this method in the use of drug discovery and development. [ABSTRACT FROM AUTHOR]

Target molecules based on Adamantane-pyrido[2,3-d]pyrimidine derivatives were prepared. Adamantane-pyrido[2,3-d]pyrimidine series using N-(hydroxyadamantan-1-yl)-5-(2,4-substitutedphenyl)-2-Methyl-4-Oxo-7-(2-oxo-2H-Chromen-3-yl)pyrido[2,3-d]Pyrimidine-3(4H) carboxamide (6a-j) was synthesized by reaction between 3-(2-chloroacetyl)-5-(2,4-substitutedphenyl)- 2-Methyl-7-(2-Oxo-2H-Chromen-3-yl) pyrido[2,3-d]pyrimidin-4(3H)-one (5a-j) and 3-aminoadamantan- 1-ol. These derivatives of Adamantane-pyrido[2,3-d]Pyrimidine were investigated In vitro for their biological characteristics against the strains which were isolated clinically and confirmation of their structure was done by FTIR, 1H-NMR, 13C NMR and LCMS. The newly synthesized derivatives gave promising antimicrobial activity. [ABSTRACT FROM AUTHOR]

In this project, crosslinked Styrene-Co-Maleic anhydride Polymer Catalyst modified with NiSO4 hexahydrate, as an efficient heterogeneous polymer-based nanocatalyst was synthesized in three steps. First, Styrene-Co-Maleic anhydride polymer was synthesized by radical polymerization of styrene in maleic anhydride, then the resulted copolymer was crosslinked with 1,3-phenylenediamine and finally the crosslinked copolymer was modified with NiSO4. This polymer-based nanocatalyst was investigated and identified using Fourier-transform infrared spectroscopy (FT-IR), Energy Dispersive X-Ray (EDX) (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM). In order to investigate the catalytic properties of CPSMA-Ni, the synthesis of various types of 2-amino-4H-chromane derivatives was investigated using the reaction of aldehyde derivatives with malononitrile in the presence of dimedone, resorcinol or naphthols. 2-Amino-4H-Cromans were synthesized with good to excellent efficiency (85%-96%) under mild conditions. This heterogeneous polymeric catalyst has a good performance in the synthesis of chromium derivatives. This catalyst can be recycled without pre-activation and reloaded up to 5 consecutive runs without significant decrease in its efficiency.

Novel 4H chromene coupled triazole hybrids 8a-l were synthesized through a hassle free multicomponent one pot synthesis and click chemistry protocols. The structures of novel compounds were established by interpretation of 1H NMR, 13C NMR, IR and Mass spectral data. The novel hybrids were screened for their invitro antioxidant activity by employing DPPH and Hydrogen peroxide radical scavenging assays, using Ascorbic acid as standard reference. Novel compounds 8h and 8i exhibited superior radical quenching percentage with IC50 value of 1.29 ± 0.35 and 1.23 ± 0.34 µM respectively, compared to the IC50 value of (1.46 ± 0.52 µM) Ascorbic acid. Compounds 8f, 8j and 8k also demonstrated best IC50 value of 3.02 ± 0.62, 2.45 ± 0.53 and 3.18 ± 0.25 µM in comparison to reference. The molecular docking studies of target compounds against the crystal structure of NADPH oxidase endorsed best docking scores and binding interactions, and are in agreement to experimental data.

Dengue fever is a mosquito-borne viral disease that has become a serious health issue across the globe. It is caused by a virus of the Flaviviridae family, and it comprises five different serotypes (DENV-1 to DENV-5). As there is no specific medicine or effective vaccine for controlling dengue fever, there is an urgent need to develop potential inhibitors against it. Traditionally, various natural products have been used to manage dengue fever and its co-morbid conditions. A detailed analysis of these plants revealed the presence of various chromene derivatives as the major phytochemicals. Inspired by these observations, authors have critically analyzed the anti-dengue virus potential of various 4H chromene derivatives. Further, in silico, in vitro, and in vivo reports of these scaffolds against the dengue virus are detailed in the present manuscript. These analogues exerted their activity by interfering with various stages of viral entry, assembly, and replications. Moreover, these analogues mainly target envelope protein, NS2B-NS3 protease, and NS5 RNA-dependent RNA polymerase, etc. Overall, chromene-containing analogues exerted a potent activity against the dengue virus and the present review will be helpful for the further exploration of these scaffolds for the development of novel antiviral drug candidates. [ABSTRACT FROM AUTHOR]

In this research, a novel bimetallic nanoparticles supported by 1,3‐bis (triethoxysilylpropyl) imidazolium hydrogen sulfate ionic liquid (Ni.Cu@SiO2.BSPIm/HSO4) are designed and prepared, and its catalytic activity is investigated in organic reaction. The prepared nanocatalyst was characterized using Fourier‐transform infrared spectroscopy (FT‐IR), energy‐dispersive X‐ray, thermogravimetric analysis, field emission scanning electron microscopy, and X‐ray powder diffraction techniques. This catalyst exhibited great activity in the one‐pot synthesis of chromene derivatives through condensation reaction. The products were obtained with high purity in high to excellent yields and short reaction times. The organic products were identified by melting points, FT‐IR, and 1H NMR analyses. [ABSTRACT FROM AUTHOR]

Marine algae that constitute hundreds of millions of tons of biomass are the oldest representatives of the plant kingdom. Recently, there has been growing interest in the utilization of algae as sustainable feedstocks for natural products with an economic value. Among these natural products are the meroditerpenoids, which are renowned for their protective effects against oxidative stress, inflammation, cancer, obesity, diabetes, and neurodegenerative disorders. Meroditerpenoids have a mixed biosynthetic origin and display a wide range of structural diversity. Their basic structure consists of a ring system bearing a diterpenoid side chain. Structural variations are observed in terms of the functional groups and saturation/cyclization of the diterpenoid side chain. This review classifies algal meroditerpenoids as plastoquinones, chromanols, chromenes, chromones, cyclic meroditerpenoids, nahocols, and isonahocols and examines their potential applications in functional foods and biopharmacology. Their lipid solubility, low molecular weight, and propensity to cross the blood-brain barrier places meroditerpenoids as potential drug candidates. There is growing interest in the study of algal meroterpenoids, and recent research has reported the structure of several new meroterpenoids and their biological activities. Further research is needed to extend the use of algal meroditerpenoids in preclinical trials. Understanding the mechanism of their biosynthesis will allow the development of de novo biosynthesis and biomimetic synthesis strategies for the industrial-scale production of meroditerpenoids and their synthetic derivatives to aid pharmaceutical research. This review is the first to summarize up-to-date information on all brown algae-derived meroditerpenoids. [ABSTRACT FROM AUTHOR]

In this research, the synthesis of novel indeno[1,2-b]pyrano[2,3-f]chromene-2,12(13H)-dione derivatives in the presence of a newly introduced magnetically recoverable nanosolid acid catalyst is reported. At the first, phosphoric acid-functionalized silica-coated Fe3O4 nanoparticles (Fe3O4@SiO2–(CH2)3OPO3H2) were prepared and well characterized using infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and energy-dispersive X-ray spectroscopy (EDS) techniques. Then, the catalytic activity of the prepared Fe3O4@ SiO2–(CH2)3OPO3H2 nanocatalyst was investigated for the synthesis of novel indeno[1,2-b]pyrano[2,3-f]chromene-2,12(13H)-dione derivatives via a one-pot and three-component condensation between 5,7-dihydroxy-4-methylcoumarin, indane-1, 3-dione, and various aromatic aldehydes under solvent-free condition. All the products are unknown, and their characterization was performed with the spectral data information obtained from their FT-IR, 1H and 13CNMR, elemental analysis, and their melting points. The reusability study of the introduced nanosolid acid catalyst showed that the catalytic stability is almost completely remained up to five consecutive runs. [ABSTRACT FROM AUTHOR]

In search of the better anticancer agents, a series of chromene based 1,2,4-oxadiazoles derivatives were synthesized using 6-fluoro-4-oxo-4H-chromene-2-carboxylic acid and readily available substituted benzonitrile. The newly synthesized derivatives were evaluated for their in vitro cytotoxic activity against MCF-7 and HeLa. Among the screened compounds, three compounds like 6-fluoro-2-(3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl)-4H-chromen-4-one (5g), 4-(5-(6-fluoro-4-oxo-4H-chromen-2-yl)-1,2,4-oxadiazol-3-yl)benzonitrile (5h), and 6-fluoro-2-(3-(3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-5-yl)-4H-chromen-4-one (5l) were found to be active against tested the cell lines. Molecular docking and ADME studies have also been conducted to complement the experimental results. [ABSTRACT FROM AUTHOR]

This study aimed to synthesize, characterize, and explore the eco-friendly and antifungal potential of precocenes and their derivatives. The organic synthesis of the mono-O-alkyl-2,2-dimethyl 2H-1-chromene series, including the natural product precocene I, and the di-O-alkyl 2,2-dimethyl-2H-1-chromene series, including the natural 2H-1-chromenes precocenes II and III, was achieved. The synthetic compounds were subjected to spectroscopic analysis, 1HNMR,13CNMR, and mass characterization. The antifungal activity of synthesized precocenes I, II, and III, as well as their synthetic intermediates, was evaluated by the poison food technique. Precocene II (EC50 106.8 µg × mL−1 and 4.94 µg mL−1), and its regioisomers 7a (EC50 97.18 µg × mL−1 and 35.30 µg × mL−1) and 7d (EC50 170.58 × µg mL−1), exhibited strong fungitoxic activity against Aspergillus niger and Rhizoctonia solani. Some of the novel chromenes, 11a and 11b, which had never been evaluated before, yielded stronger fungitoxic effects. Finally, docking simulations for compounds with promising fungitoxic activity were subjected to structure–activity relationship analyses against the polygalactouronases and voltage-dependent anion channels. Conclusively, precocenes and their regioisomers demonstrated promising fungitoxic activity; such compounds can be subjected to minor structural modifications to yield promising and novel fungicides. [ABSTRACT FROM AUTHOR]

The review describes syntheses of new benzo-fused spiro heterocycles by reactions of isatins, oxindoles, and indenoquinoxalines with nitroalkenes, chalcones in the presence of proline or thioproline, amino acids, malononitrile, cyclic and acyclic aliphatic 1,3-diketones or aldehydes, and ethyl acetoacetate. Some compounds exhibiting various biological activities have been noted. [ABSTRACT FROM AUTHOR]

Background: Sulfonamide derivatives are well-reported hCA IX inhibitors; however, they inhibit all types of hCA without any selectivity, leading to severe adverse effects. Hence, developing a novel nonsulfonamide class of tumor-associated hCA IX inhibitors through non-classical inhibition may provide greater selectivity and better pharmacokinetics., Objective: The objective of this study was to develop non-sulfonamide derivatives as potential human carbonic anhydrase (hCA) inhibitors and develop a new series of chromene-linked bis-indole derivatives., Methods: We synthesized and characterized the chromene-linked bis-indole derivatives and further evaluated them against four hCA isoforms, i.e., hCA I, hCA II, hCA IX, and hCA XII, and determined the ADMET parameters by the In-silico method., Results: Most of the compounds showed significantly greater affinity and selectivity towards the tumorassociated hCA IX over other hCA isoforms within the lower micromolar to submicromolar range. In particular, the bromo-substituted bis-indole derivative 6t showed an excellent inhibition of hCA IX isoform with an affinity (Ki) of 2.61 μM. In contrast, the cyano group substituted bis-indole derivative 6s and also displayed a strong inhibition of hCA IX isoform with an affinity (Ki) of 2.73 μM. Many other potential candidates, including 6g, 6i, 6k, 6m, 6o, 6p, and 6r, showed higher affinity at tumor-associated hCA IX with lower than 10 μM compared to other hCA isoforms., Conclusion: Therefore, the chromene-linked bis-indole derivatives can serve as a novel non-sulfonamide class of tumor-associated hCA IX inhibitors., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Three series of thiazolidinedione (TZD) derivatives (5a-f, 7a-f, and 9a-f) were prepared efficiently. Afterward, the synthesized candidates' antibacterial efficacy against both gram-positive and gram-negative bacteria was assessed. Compounds 7c, 7d, and 7f had values comparable to that of ampicillin, a reference antibiotic, whereas compounds 5c, 5d, and 7e exhibited the greatest values (23.0±1.0, 27.7±0.6, and 20.0±1.0, respectively) against gram-positive bacteria (Staphylococcus aureus). The optimal structure of the produced molecules was determined by DFT computing. To assess the binding energy and elucidate the interaction between the potential candidates and different proteins, in silico docking is employed. ADMET analysis to assess the synthesized compounds' toxicity, metabolism, excretion, distribution, and absorption., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)

An intramolecular charge transfer (ICT)–based fluorescent probe P-ONOO− was synthesized to detect ONOO−. After responding to peroxynitrite, the dicyano-vinyl group of P-ONOO− generates the aldehyde group, emitting strong green fluorescence accompanied by quenching of the yellow fluorescence. According to the calculated Fukui function, the modification of the alkoxy group can enhance the f+ of P-ONOO−, which can enhance the probe's nucleophilic addition reactivity with ONOO−. It has been experimentally verified that P-ONOO− shows fast response (within 30 s), excellent sensitivity (the detection limit = 10.4 nM), and good selectivity towards ONOO−. Additionally, the probe P-ONOO− has high membrane permeability and good biocompatibility, which can image endogenous ONOO− and exogenous ONOO− in HeLa cells. [ABSTRACT FROM AUTHOR]

The present work highlights a rapid, efficient, eco-friendly protocol for synthesizing one-pot polyhydroquinolines via Hantzsch reaction and 2-amino-4H-chromene derivatives under catalyst-free condition. The present mild and greener method uses ethanol: water (1:1) without catalyst at R.T. and 90 °C. The structurally diverse substrates were selected to ascertain the ability of the current approach to handle different functional groups, including ketones as one of the substrates. The current methodology is economical and environmentally friendly for the three and four-component reaction of aliphatic, acyclic, aromatic, heterocyclic aldehydes in shorter reaction time, simple workup procedure, no catalyst with excellent yields, and high atom efficiency are the added advantages of this protocol. [ABSTRACT FROM AUTHOR]

An efficient synthesis of some new chromene derivatives by condensing a series of aromatic aldehydes with 4-hydroxycoumarin and 3,4-methylenedioxyphenol catalyzed by Ag2Cr2O7 nanoparticles in aqueous media at room temperature is described for the first time. Avoiding hazardous solvent, using inexpensive, recyclable and nontoxic catalyst, very mild reaction conditions, high yields of products, short reaction time, simple experimental, and easy purification are the remarkable advantages of this procedure. A feasible protocol for the preparation of some new chromene derivatives in aqueous media at room temperature. The use of Ag2Cr2O7 nanoparticles as efficient catalyst under very mild reaction conditions for the synthesis of the above-mentioned compounds is described for the first time. The catalyst can be recovered and reused in at least four consecutive reactions without observation of appreciable loss in its catalytic activity. [ABSTRACT FROM AUTHOR]

Many novel thiazole derivatives were designed and synthesized using 4-phenylthiazol-2-amine. The reactivity of the latter compound toward different chemical reagents was studied. The structure of the newly synthesized compounds was established based on elemental analysis and spectral data. Furthermore, twenty compounds of the synthesized systems were selected and evaluated in (µM) as significant anticancer agents towards three human cancer cell lines [MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), and SF-268 (CNS cancer)] and normal fibroblasts human cell line (WI-38). The results showed that compounds 9 and 14a displayed higher effeciency than the reference doxorubicin.