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In this article, three unsymmetrical 7-(diethylamino)quinolone chalcones with D-π-A-D and D-π-A-π-D type push-pull molecular arrangements were synthesized via a Claisen-Schmidt reaction. Using 7-(diethylamino)quinolone and vanillin as electron donor (D) moieties, these were linked together through the α,ß-unsaturated carbonyl system acting as a linker and an electron acceptor (A). The photophysical properties were studied, revealing significant Stokes shifts and strong solvatofluorochromism caused by the ICT and TICT behavior produced by the push-pull effect. Moreover, quenching caused by the population of the TICT state in THF-H2O mixtures was observed, and the emission in the solid state evidenced a red shift compared to the emission in solution. These findings were corroborated by density functional theory (DFT) calculations employing the wb97xd/6-311G(d,p) method. The cytotoxic activity of the synthesized compounds was assessed on BHK-21, PC3, and LNCaP cell lines, revealing moderate activity across all compounds. Notably, compound 5b exhibited the highest activity against LNCaP cells, with an LC50 value of 10.89 µM. Furthermore, the compounds were evaluated for their potential as imaging agents in living prostate cells. The results demonstrated their favorable cell permeability and strong emission at 488 nm, positioning them as promising candidates for cancer cell imaging applications.

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Ultrasound-assisted synthesis of pyrimido|quinolindione derivatives via a multicomponent reaction and subsequent formylation with Vilsmeier-Haack reagent were performed. Compounds were prepared by a one-pot method from aminopyrimidinones, dimedone and aromatic aldehydes through a Mannich-type reaction sequence, and then functionalized under ultrasound irradiation and Vilsmeier-Haack conditions to give ß-chlorovinylaldehyde products. Ultrasonically assisted reactions, experimental simplicity, good yields without using metallic catalysts and the control of hazardous material release are features of this simple procedure.

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This study presents the first report of plastics in the geological record (rocks and formations composed of plastics) along the central Caribbean Coast of Colombia, northern coast of South America. These novel records of pollution include two rock types (plastiglomerates and quartz plastisandstones), two altered plastic types (pyroplastics and plasticrusts), two soil types (plasticlasts and anthrosols), and a series of artifacts (fossils) found near human settlements. All of them were analyzed using Fourier Transform Infrared (FTIR) spectroscopy. Polyester, high-density polyethylene, and copolymers of alkyl acrylates or methacrylates were identified as the principal polymers forming these rocks. This research provides new insights into the petrology of these emerging new forms of pollution, for which humans are primarily responsible for their generation and distribution. Similarly, the results presented emphasize that plastics are generating a deluge of pollutants in terms of variety and volume, overwhelming natural environments globally. Controlling or even eliminating their use has become one of the most significant challenges of the 21st Century.

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The growing literature on microplastics (MPs) in coastal and marine environs reflects the seriousness of this pollutant category. Diverse litter studies on Colombia's Central Caribbean Coast have not presented detailed study of MPs' typology, magnitude or distribution. This baseline study presents for first time the MPs problem on 23 beaches in 75 km coastal reach between Punta Roca and Galerazamba, on the central Colombian Caribbean Coast. The Microplastics Pollution Index (MPPI) and Coefficient of Microplastic Impact (CMPI) were developed and applied along with the Environmental Status Index (ESI) and their integration through sector analysis, and mapping using Agglomerative Hierarchical Clustering and Multidimensional Scaling, and Principal Components Analysis. Microplastics abundances (densities) ranged from 2457 to 557 MPs/kg, similar to other global beaches and bays. The MPs Index for the 23 beaches classified 8 beaches as "Moderate," 10 beaches as "High" and 5 as "Very High." Microplastic fibers were the dominant typology at 83% of the combined beaches total (ranging from Moderate to Very High for individual beaches).

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The use of dyes at an industrial level has become problematic, since the discharge of dye effluents into water disturbs the photosynthetic activity of numerous aquatic organisms by reducing the penetration of light and oxygen, in addition to causing carcinogenic diseases and mutagenic effects in humans, as well as alterations in different ecosystems. Chitosan (CS) is suitable for removing anionic dyes since it has favorable properties, such as acquiring a positive charge and a typical macromolecular structure of polysaccharides. In this study, the optimization of CS beads crosslinked with glutaraldehyde (GA) for the adsorption of reactive blue dye 4 (RB4) in an aqueous solution was carried out. In this sense, the response surface methodology (RSM) was applied to evaluate the concentration of CS, GA, and sodium hydroxide on the swelling degree in the GA-crosslinked CS beads. In the same way, RSM was applied to optimize the adsorption process of the RB4 dye as a function of the initial pH of the solution, initial concentration of the dye, and adsorbent dose. The crosslinking reaction was investigated by scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), and X-ray diffractometry (XRD). The design described for the swelling degree showed an R2 (coefficient of determination) adjusted of 0.8634 and optimized concentrations (CS 3.3% w/v, GA 1.7% v/v, and NaOH 1.3 M) that were conveniently applied with a concentration of CS at 3.0% w/v to decrease the viscosity and facilitate the formation of the beads. In the RB4 dye adsorption design, an adjusted R2 (0.8280) with good correlation was observed, where the optimized conditions were: pH = 2, adsorbent dose 0.6 g, and initial concentration of RB4 dye 5 mg/L. The kinetic behavior and the adsorption isotherm allowed us to conclude that the GA-crosslinked CS beads' adsorption mechanism was controlled mainly by chemisorption interactions, demonstrating its applicability in systems that require the removal of contaminants with similar structures to the model presented.

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Along 24 beaches of the Central Caribbean Coast of Colombia, plastic items were collected and grouped into 43 different typologies. The average plastic abundance was 4.54 items/m2 being eight typologies responsible for 82% of all plastic collected. The application of the Clean Coast Index (CCI) and the Plastic Abundance Index (PAI) allows categorization of the study area as "Extremely Dirty" coastal strip with a "Very High Abundance" of plastics. Beaches were statistically grouped into three specific types: moderate, bad and extremely bad environmental conditions. The typology and magnitudes of plastics found in the study area suggest a combination of sources that primarily include dumping and direct activities on the beach. Plastic medical and sanitary waste, ocean/waterway items, and plastic items related to smoking-related activities also were observed.

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A total of 5993 litter items divided into 13 categories were found at 25 beaches located along the Atlantico Department coastline, Caribbean of Colombia, with an average litter abundance of 7 items/m. Agglomerative Hierarchical Clustering (AHC), Multidimensional Scaling (MDS) and Principal Components Analysis (PCA) were applied with the objective of highlighting similarities and contrasts between litter categories and abundances. Results indicated two specific groups of beaches in terms of amounts of litter. The first group is composed of 17 "dirty beaches" (urban, resort and village) while the second group includes 8 "clean beaches" (village and resort). This division was confirmed by means of the EA/NALG (2000) grading system, which highlighted that 68% of beaches belonging to the Atlantico Department coastline are in an unacceptable condition of cleanness. Current patterns of litter abundance and accumulation are related to sources as well as beach characteristics such as degree of exposition and morphodynamic state.

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A small series of tetrahydroindazoles was prepared, starting from 2-acetylcyclohexanone and different hydrazines using reflux and a focused microwave reactor. Microwave irradiation (MW) favored the formation of the desired products with improved yields and shortened reaction times. This is a simple and green method for the synthesis of substituted tetrahydroindazole derivatives. The in vitro antioxidant activity was evaluated using the DPPH and ABTS methods. In these assays, 2-(4-fluorophenyl)-3-methyl-4,5,6,7-tetrahydro-2H-indazole (3f) showed moderate DPPH decoloring activity, while 3-methyl-4,5,6,7-tetrahydro-1H-indazole (3a), 3-methyl-2-phenyl-4,5,6,7-tetrahydro-2H-indazole (3b) and 2-(4-fluorophenyl)-3-methyl-4,5,6,7-tetrahydro-2H-indazole (3f) were the most active in the ABTS assay. All compounds were well characterized by IR, ¹H-, (13)C-NMR and GC-MS spectroscopy and physical data, while the structure of 4-(3-methyl-4,5,6,7-tetrahydro-2H-indazol-2-yl)benzoic acid (3e) was also determined by single crystal X-ray analysis.

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The reaction between 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde and phenylhydrazine proceeds via condensation to provide the title compound, C17H15ClN4, (I), rather than via the alternative routes of simple nucleophilic substitution or cyclocondensation. With the exception of the phenyl group bonded directly to the pyrazole ring, the non-H atoms of (I) are nearly coplanar, with an r.m.s. deviation of 0.058 Å. The molecules are linked into C(7) chains by a single N-H···N hydrogen bond, and the chains are linked by π-π stacking interactions to form sheets.

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The title compound, C23H17N3O4S, crystallizes with Z' = 3 in the space group P-1. Two of the three independent molecules are broadly similar in terms of both their molecular conformations and their participation in hydrogen bonds, but the third molecule differs from the other two in both of these respects. The molecules are linked by a combination of N-H...O, N-H...N, C-H...O, C-H...N and C-H...π(arene) hydrogen bonds to form a continuous three-dimensional framework structure within which a centrosymmetric six-molecule aggregate can be identified as a key structural element.

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The molecules of the title compound, C13H18N6O2S2, lie across twofold rotation axes in the space group C2/c. Although the pyrimidine ring is effectively planar, the bridging methylene C atom is displaced from the plane of the pyrimidine ring by 0.213 (2) Å, while the C-C-C angle at the bridging C atom is 120.3 (2)°. The molecule contains two symmetry-related N-H···O hydrogen bonds, generating S(8) motifs, and intermoecular N-H···O hydrogen bonds link the molecules into a ribbon of edge-fused rings.

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The title compound, C16H9FN2S, crystallizes as a nonmerohedral twin with twin rotation about the reciprocal-lattice vector [101]*. The molecules are nearly planar and the dihedral angle between the planes of the two aryl rings is only 4.4 (2)°. The molecules are linked by pairs of C-H···N hydrogen bonds to form cyclic centrosymmetric R2(2)(18) dimers, which are linked into chains by an aromatic π-π stacking interaction. Comparisons are made with some related 3-aryl-2-thienylacrylonitriles.

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Claisen-Schmidt condensation reaction of 4-acetamidoacetophenone with aromatic aldehydes under ultrasonic irradiation affords acetylaminochalcones (yields: 71-90%) which also under ultrasonic irradiation and in the presence of sodium acetate and acetic acid aqueous undergo facile and clean cyclocondensation with hydrazine to afford 3-(4-acetamidophenyl)-5-(aryl)-1-H-pyrazolines. The pyrazolines were obtained in good to excellent yields (81-89%), and were characterized by conventional spectral data. The work-up is simple and the results obtained indicate that, unlike classical heating, ultrasonic irradiation results in higher yields, shorter reaction times (1.5-2.3 h) and milder conditions.

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(E)-2-(benzo[d]thiazol-2-yl)-3-heteroarylacrylonitriles are described as a new class of selective inhibitors of acetylcholinesterase (AChE). The most potent compound in the series exhibited good AChE inhibitory activity (IC50 = 64 µM). Compound 7f was found to be more selective than galanthamine in inhibiting AChE and it showed a moderate selectivity index. Kinetic studies on AChE indicated that a competitive type of inhibition pattern exist for these acrylonitrile derivates. Molecular docking models of the ligand-AChE complexes suggest that compound 7 g is located on the periphery of the AChE active site.

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A series of pyrimido[4,5-b]quinolines (5-deazaflavines), were synthesized by microwave assisted intramolecular cyclization. The N4-substituted-2,4-diamino-6-chloro-pyrimidine-5-carbaldehydes, were prepared by selective monoamination of 2-amino-4,6-dichloropyrimidine-5-carbaldehyde with aliphatic and aromatic amines.

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In the title compound, C(18)H(15)N(4)O(+).Cl(-).1.5H(2)O, one water site is fully ordered with unit occupancy while the other, which lies close to an inversion centre in the space group C2/c, has only 0.5 occupancy. The cation exhibits bond fixation in the fused carbocyclic ring and electronic polarization in the terminal heterocyclic ring. The components are linked into complex sheets by a combination of N-H...O, N-H...Cl, O-H...O, O-H...Cl and C-H...O hydrogen bonds.

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The molecules of the title compound, C(22)H(21)ClN(4)O, are conformationally chiral, and in the space group P2(1)2(1)2(1) each crystal contains only one conformational enantiomer. The intramolecular dimensions provide evidence for polarization of the electronic structure. Molecules are linked by a single C-H...pi(arene) hydrogen bond into chains, which are themselves weakly linked into sheets by an aromatic pi-pi stacking interaction.

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In each of 2-amino-4-(piperidin-1-yl)-11H-pyrimido[4,5-b][1,5]benzodiazepin-6-ium chloride monohydrate, C(16)H(19)N(6)(+).Cl(-).H(2)O, (I), and 2-amino-4-[methyl(2-methylphenyl)amino]-11H-pyrimido[4,5-b][1,5]benzodiazepin-6-ium chloride-benzene-1,2-diamine (1/1), C(19)H(19)N(6)(+).Cl(-).C(6)H(8)N(2), (II), the seven-membered ring in the cation adopts a boat conformation. The pyrimidine ring in (II) adopts a twist-boat conformation, but the corresponding ring in (I) is essentially planar. The amino groups of the benzene-1,2-diamine component of (II) are both pyramidal. The independent components of (I) are linked into complex sheets by a combination of N-H...O, N-H...N, N-H...Cl and O-H...Cl hydrogen bonds. In the crystal structure of (II), one N-H...N hydrogen bond and six independent N-H...Cl hydrogen bonds combine to link the components into complex sheets.

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In 6-(4-bromophenyl)-3-methyl-1-phenyl-4,5-dihydro-1H-pyrazolo[3,4-b]pyridine, C(19)H(16)BrN(3), the reduced pyridine ring adopts a conformation that is close to a screw-boat form. Molecules are linked by pairs of symmetry-related C-H...pi(arene) hydrogen bonds into cyclic centrosymmetric dimers. Molecules of 3-(4-nitrophenyl)-4-phenyl-1H-pyrazolo[3,4-b]pyridine, C(18)H(12)N(4)O(2), are linked into centrosymmetric R(2)(2)(8) dimers by pairs of symmetry-related N-H...N hydrogen bonds, and these dimers are linked by pairs of C-H...pi(pyridine) hydrogen bonds to form a chain of edge-fused rings, or a molecular ladder, along [100]. The molecular aggregation in this compound is completed by two weak C-H...O hydrogen bonds, one of which links the chains along [100] into sheets.

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In the title compound, C(11)H(11)N(3)O.0.5H(2)O, the water molecule lies across a twofold rotation axis in the space group Pbcn. The bond distances in the organic component provide evidence for polarization of the electronic structure. The molecular components are linked into puckered sheets of R(10)(8)(34) rings by a combination of O-H...N and N-H...O hydrogen bonds; adjacent sheets are weakly linked by an aromatic pi-pi stacking interaction. Comparisons are made with some fused-ring analogues.