Proceedings, 2019, ECSOC-23 2019

Amphiphilic molecules have been actively explored as promising materials in the field of bio and nanotechnology. These molecules are constituted by a polar head and a lipophilic tail and in an aqueous medium are self-assemble to form different types of macromolecular structures such as micelles, monolayer vesicles, bars, sheets and tubes. In this work, a convergent synthetic approach for the synthesis of two new amphiphilic compounds based on a versatile amino polar head, a tetraethylene glycol spacer and a lipophilic tail derived from oleic acid has been developed. Subsequently, after a self-assembly process in aqueous medium, nanostructures as micelles have been obtained and characterized. Finally, a procedure for the inclusion of the highly lipophilic drug Dexamethasone has been carried out in order to study the ability of these micelles to act as nanovectors for drug delivery. Full article

Ionic liquids (ILs) are mostly composed of organic cations and organic/inorganic anions. One of the most important class of ILs are imidazolium ILs. The hydrophilicity and hydrophobicity of ILs are regularly influenced by length of alkyl side chain of cation. According to this effect, better hydrophilicity comes from a shorter alkyl side chain and on the contrary, better hydrophobicity comes from a lengthier alkyl side chain of cation. Typical ILs have exceptional properties. Most ILs are stable at about 300 °C in the liquid state at normal conditions. Due to the exceptional properties of ILs, they have been used in diverse industries including batteries and fuels. As solvents, ILs have been employed in many chemical fields. Solubilities of ILs with organic/inorganic species are completely satisfactory. Here, by N-methyl imidazole (Im), 1,3-dibromopropane, triethanolamine (TEA), and ZnBr₂, new ionic liquid (TEA-Im-Zn) was synthesized and used as catalyst and solvent in the synthesis of functionalized 1-benzamino-1,4-dihydropyridine using aromatic aldehydes, malononitrile, triethylamine, arylamine and dialkyl acetylenedicarboxylate. Full article

The sensors modified carbon nanotubes and molecularly imprinted polymers are an excellent choice for the determination of D-arabinose, because they have high selectivity and sensitivity for analysis. This allows the control and optimization of the second generation ethanol production process, given the clear understanding of the chemical changes that occur through the hydrolysis of lignocellulosic biomass. For this reason, the present work presents a chemical study of the functional groups of the chemical species present on the sensor surface by the Fourier transform infrared spectroscopy (FT-IR) technique and a morphological analysis by the scanning electron microscopy (SEM) technique. Full article

In certain countries, many of the reagents used to transform carboxylic acids to acyl halides such as phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride, phosphoryl chloride, thionyl chloride and sulfuryl chloride are difficult to come by. Against this background, the authors developed the reaction system triphenylphosphine (PPh₃)–bromotrichloromethane (BrCCl₃) to prepare acyl halides in situ. In the following, the use of this reagent combination is joined with the reaction of the in situ prepared acyl halides with nitrogen nucleophiles, specifically with hydrazines, methylamine and anilines. The reaction is also used in an intramolecular variant by the reaction of maleanilic acids to N-arylmaleimides. Full article

An eco-friendly methodology for the synthesis of novel Schiff base analogs of Raltegravir, an Integrase inhibitor drug is described. Pertinence of these imine derivatives is related to Medicinal Chemistry to develop new anti-VIH compounds. To our knowledge, this is the first report of the synthesis of Schiff base using a Raltegravir drug fragment as amino component. In addition, these Imines will be used as a synthetic precursor to prepare other nitrogen heterocycles of biological relevance such as 1,5-disubstituted Tetrazoles. Full article

Activated alkenes such as cinnamates and chalcones can easily be converted to 2,3-dideuterio-arylpropionates and dideuteriochalcones, respectively, by the action of NaBD₄, AcOD in the presence of Pd on carbon. Toluene or benzene was used as solvent. It was shown that Pd on carbon was necessary for the reaction to proceed. Deuterium addition experiments were also carried out with NaBD₄, AcOD, D₂O in the presence of Pd on carbon. Full article

Six 1,3-oxazoles were synthetized in moderate to good yields by Van Leusen reaction in a pressure reactor. The methodology allowed to decrease the reaction times reported in the literature from hours to 20 min. In addition, preliminary qualitative recognition of cations with some synthetized oxazoles such as Hg²⁺, Ni²⁺, Zn^2+, Ag⁺, Cu²⁺, Pb²⁺ was done and a “turn off” effect was observed with Ni²⁺. Finally, the 1,3-oxazoles could be of biological relevance because they are considered privileged nucleus in medicinal chemistry and therefore will be useful to obtain pharmacophoric hybrid molecules. Full article

We have developed a new idea to synthesize key intermediate molecule by utilizing deep eutectic solvent (DES) and ultrasound in a multistep reaction to ensure process cost-effective. Key intermediate (3) and final compounds (4a–n) were synthesized in a higher yield of 95% and 80–88% respectively. Further, final compounds (4a–n) were assessed for their anti-inflammatory, analgesic, ulcerogenic and lipid peroxidation. The compounds 4f, 4g, 4j, 4l, and 4m showed good anti-inflammatory activity, while 4f, 4i, and 4n exhibited very good analgesic activity as compared to the standard drug. The ulcerogenicity of selected compounds was far less than the indomethacin. The ligands had also shown a good docking score (4f = −6.859 and 4n = −7.077) as compared to control indomethacin (−6.109).State-of-art DFT theory was used to validate the lipid peroxidation mechanism of the active compounds which was in good agreement with the variations of BDEs and IP of the tested compounds. Full article

Although the wide arsenal of drugs available to treat bacterial infections, emerging drug-resistant bacterial pathogens have recently highlighted an urgent need to find new more effective and less toxic therapeutic agents. Fluoroquinolones, including norfloxacin, are antibiotics showing a concentration-dependent bactericidal capacity due to the activity inhibition of DNA-gyrase and topoisomerase IV, which are enzymes essential for bacterial DNA replication. Naphthoquinones are secondary metabolites showing different biological activities, including cytotoxic, antibacterial and antifungal effects. In particular, the efficacy of natural and synthetic 1,4-naphthoquinone derivatives is likely due to their oxidizing/reducing capability, through which they destroy cellular targets as nucleic acids. Hybrid molecules are produced combining structural features of two or more bioactive compounds, in order to obtain new therapeutic agents able, not only to reduce undesirable side effects of the parent drugs, but also to inhibit more biological targets, hopefully with a better therapeutic property than the administration of combined single-target drugs. With the aim to apply this strategy in the study of new potential antimicrobial agents, we have synthesized four hybrid molecules by the reaction of norfloxacin with suitable quinones and their activities have been evaluated against both bacteria and fungi, in comparison with synthetic precursors. The experimental data are supported by docking calculations on S. aureus DNA-gyrase, discussing the interactions involved for each hybrid molecule, in comparison with norfloxacin and the original ligand moxifloxacin. Full article

A new series of 5-acetylbarbituric based thiosemicarbazones named 5-acetylbarbituric hydrazine-1-carbothioamide (Acb4NDH, 1), N-methyl-(5-acetylbarbituric)hydrazine- 1-carbothioamide (Acb4NM, 2), N-ethyl-(5-acetylbarbituric)hydrazine-1-carbothioamide (Acb4NE, 3), N,N-dimethyl-(5-acetylbarbituric)hydrazine-1-carbothioamide (Acb4NDM, 4), N′-piperidine- (5-acetylbarbituric)-1-carbothiohydrazide (Acb4Npip, 5) and N′-hexamethyleneimine- (5-acetylbarbituric)-1-carbothiohydrazide (Acb4Nhexim, 6), has been synthesized from 5-acetylbarbituric acid and N-unsubstituted/substituted thiosemicarbazides. The synthesized compounds were well characterized by elemental analyses, FT-IR, ¹H, ¹³C NMR and mass spectroscopic methods. Three-dimensional molecular structures of three compounds (1, 2 and 6) and of N,3-dimethyl-4-(5-(methylamino)-1,3,4λ⁴-thiadiazol-2-yl)-5-oxo-2,5-dihydro-1H-pyrazole- 1-carbothioamide ethyl sulfate salt (7) were determined by single crystal X-ray crystallography. The compounds were evaluated for their in vitro cytotoxicity against HeLa-229 cancer cell line. Full article

A series of six di- and tri-halogenated N-arylcinnamanilides designed as anti-inflammatory and antimicrobial agents was prepared and characterized. Since it is known that lipophilicity significantly influences the biological activity of compounds, the hydro-lipophilic properties of these di- and tri-substituted N-arylcinnamanilides were investigated in the study. All the discussed derivatives of cinnamic acid were analyzed using the reversed-phase high performance liquid chromatography method to measure lipophilicity. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped non-polar C₁₈ stationary reversed-phase column. In the present study, the correlations between the logarithm of the capacity factor k and log P/Clog P values calculated in various ways as well as the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed. Full article

Several synthetic routes have been achieved to synthesize pyrane fused systems. As a follow up of earlier work, we hereby report the microwave assisted synthesis of key intermediate, pyrane fused acridine compounds 3a–f. It was obtained by treating α,β-unsaturated ketone 1a–f and malononitrile 2 in presence of piperidine with ethanolic solution at 50 C under 200 W power. This method also optimized via microwave method using RSM methodology. All the synthesized derivatives and target compounds were evaluated for cytotoxicity effect on human hepatoblastoma (HepG2) cell line and HDAC enzyme activity. Full article

Chalcones are a group of compounds that belong to the flavonoid family and have a wide variety of uses, including a high therapeutic potential for multiple diseases, such as, anticancer, antifungal or antibacterial agents. As is well known, chalcones are commonly synthesized by Claisen-Schmidt condensation, aldol condensation involving the appropriate aldehydes and ketones, in presence of acid or base as catalyst followed by dehydration reactions. However, under conventional conditions it is carried out with prolonged reaction times and requires expensive catalysts. For this reason, alternative source of energy, microwave or ultrasound, are employed. On the other hand, in all chemical processes a considerable amount of variables (instrumental parameters, reagents, temperatures, times, etc.) take part so a large number of experiments must be carried out in order to define the optimal conditions. In addition, the experimental design technique -important tool- allows the optimization of conditions leading to better yields in shorter times. Here and in line with previous research, we explore the synthesis, assisted by ultrasound, of (E)-1,3-diphenyl-2-propen-1-one like a model reaction. Taguchi Design was the mathematical method employed to determine the best working condition. In conclusion, the desired product is obtained quantitatively, without undesired by-products, and in short reaction times. Additionally, the reaction was used, as an alternative method, to monitor the ultrasound equipment using the control chart methodology (Shewhart chart), which allowed us to study how a process changes over time. Full article

Currently, constructing solid acid catalysts with well-defined structures, environmentally benign, with high catalytic activity, easy separation, and high chemical stability is the most important area of industrial and environmental concern. Over the past few decades, porous conjugated polymers have been employed as stable catalyst supports for various organic transformations. Among these materials, graphitic carbon nitride (g-C₃N₄) has been widely studied in the field of photocatalysis and heterogeneous catalysis, due to its high surface area and great physical and chemical stability. Herein, we report the synthesis of sulfonated graphitic carbon nitride (Sg-C₃N₄) as an efficient solid acid catalyst for the preparation of various biologically nitrogen-containing heterocyclic compounds under mild reaction conditions. Full article

New coumarin namely 2-(3-(7-methylcoumarin)acetamido)benzoic acid (MAB) was successfully synthesized by reaction of ethyl 2-(7-methylcoumarin)acetate with anthranilic acid. The chemical structure of MAB was confirmed by FT-IR, NMR spectroscopies and Elemental Analysis. The inhibition performance of MAB was investigated using the weight loss method. The results illustrate the strong adsorption of MAB molecules on the mild steel coupon surface and this adsorption follows the Langmuir adsorption isotherm. DFT calculations were performed to show the relationship between the MAP molecular structure and inhibition performance. Full article

A series of isoxazole based (E)-1-(isoxazole-5-yl)-3-(substituted phenyl)-prop-2-en-1-ones (chalcones, 3a-3o) and 3-(isoxazol-5-yl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carboxamide (dihydropyrazoles, 4a-4o) were synthesized, characterized and evaluated for their antimicrobial, antioxidant and anticancer properties. Chalcones exhibited excellent antibacterial and antioxidant activities whereas the dihydropyrazoles shown superior antifungal and anticancer activities. The compound 3l containing 3,4,5-trimethoxy phenyl ring showed the potent antibacterial activity (MIC = 1 µg/mL) as well as the antioxidant activity (IC50 = 5 µg/mL) whereas the dihydropyrazole, 4o (MIC = 0.5 µg/mL) bearing the 2-chloro-3,4-dimethoxyphenyl was the potent antifungal compound identified. The dihydropyrazoles 4n and 4h possessing 2-fluoro-3,4-dimethoxyphenyl and 3,4-dimethoxyphenyl substituents exhibited potent anticancer activity against prostate cancer cell line (DU-145) with MIC 2 and 4 µg/mL respectively. The structure activity relationships had shown that there is a marked influence of both electron withdrawing halogens and electron releasing methoxyl groups on the above biological activities. All the compounds were evaluated for toxicity on normal human cell lines (LO2) and found to be non-toxic. These studies could help to synthesize, explore and identify new isoxazole containing leads for antimicrobial, antioxidant and anticancer properties. Full article

A series of 1,3,5-triazine derivatives, incorporating aminobenzenesulfonamide, aminoalcohol/phenol, piperazine, chalcone, or stilbene structural motifs, were evaluated as potential antioxidants. The compounds were prepared by using step by step nucleophilic substitution of chlorine atoms in starting 2,4,6-trichloro-1,3,5-triazine. Reactions were catalyzed by Cu(I)-supported on a weakly acidic resin. The radical scavenging activity was determined in terms of %inhibition activity and IC₅₀, using the ABTS method. Trolox and ascorbic acid (ASA) were used as standards. In the lowest used concentration 1 × 10⁻⁴ M, the %inhibition activity at time 0 min was comparable with both standards at least for 10 compounds. After 60 min compounds 1, 2, 9 and 25 showed nearly twice %inhibition (73.44–87.09%) in comparison with standards (Trolox = 41.49%; ASA = 31.07%). Values of IC₅₀ correlated with %inhibition activity. For compounds 1, 2, 9 and 25 values of IC₅₀ in time 60 min (17.16–27.78 μM) were 5 times lower than IC₅₀ of both standards (Trolox = 178.33 μM; ASA = 147.47 μM). Based on these results, the presented 1,3,5-triazine derivatives and their analogs have a high potential in the treatment of illnesses caused or related to oxidative stress. Full article

Herein, we describe the synthetic route to access a red-emitting BODIPY from its α-diformylated precursor. The photophysical signatures of this dye are sensitive to the presence of thiol-containing amino acids (like cysteine, homocysteine, and glutathione) in the surrounding environment. This sensor provides up to three detection channels to monitor and quantify these biomolecules, even at low concentrations (down to micromolar). Moreover, owing to the pronounced splitting of the spectral band profile induced by these amino acids, the detection can be visualized following just the evolution of the fluorescence color by the naked eye. Full article

In recent years, the many alluring methods to prepare inorganic-organic hybrid nanomaterials have garnered great interest. The in-situ growth phenomenon is the most straightforward way to form these compounds with multiply dimensions. Here in, we demonstrate the in-situ synthesis of noble metal nanoparticles-polyacrylonitrile nanofibers (M NPs-PAN NFs) using an electrospinning route. Synthesis includes two main paths in the presence of dimethyl formamide (DMF). In the first path, the M NPs were prepared from the precursor solution using an in-situ reduction route in the presence of ultrasound irradiation and DMF (as a solvent and weak reducing agent) at 60 °C for nine min. The mechanism of our second path exhibited that the polymer matrix solution (PAN/DMF) acts as an appropriate host solution for the MNPs, due to possessing a high contents of effectiveness groups. These groups not only anchor NM NPs tightly in PAN fibers via dipole-induced dipole interactions but also they stabilize metal nanoparticles by good bonding interaction with their surface atoms. After preparing all nanofibers, TEM images revealed that both M NPs and their related nanofibers have a particular and unique shape without agglomerated particles with different sizes. Field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD), energy-dispersive x-ray spectroscopy (EDS), and Fourier-transform infrared (FT-IR) were also applied to verify the formation of all samples. In this report, we tried to present a preparative synthesis strategy to the preparation of nanofibers. Full article

Radical cyclizations represent powerful synthetic strategies for the assembling of heterocycles. Most radical cyclizations are based on the addition to C C double or triple bonds. On the contrary, the addition to C O double bonds is rarely reported, since it proceeds reversibly due to the formation of thermodynamically unfavorable alkoxy radicals. Herein we report our attempts to construct substituted pyrrolidin-3-ols by tin-mediated radical cyclization of 5-phenylseleno-3-aza-pentanals. These rings are widely represented in natural products and drug candidates with various biological activities. Full article

Prostaglandins (PGs) with cytoprotective activity were studied for a long time, and a few PGE₁ and PGE₂ stable analogues were promoted as drugs: arbaprostil, enprostil, misoprostol, and rioptostol. Similarly, nocloprost, a 9β-chlorine prostaglandin analogue, and many 9β- and 11β-substituted prostaglandins were synthesized and studied for their biological activity. We previously synthesized new 9β-halogenated prostaglandins with an ester group at the carbon atom 6 (PGs numbering) by the reaction of a δ-lactone intermediate with diols in acid catalysis. These compounds were used in the current molecular docking study to determine their potential cytoprotective (anti-ulcer) activity. The current study was done with the CLC Drug Discovery Workbench 2.4. software and an oxidoreductase enzyme receptor, chosen from the Protein Data Bank, ID: 4KEW (www.rcsb.org). We used two recognized drugs, omeprazole (co-crystallized with the enzyme) and nocloprost, as the standard. The 9β-halogenated prostaglandin analogs were docked. Nocloprost and all 9β-halogenated compounds had docking scores greater than that of omeprazole. The majority of the 9β-halogenated analogs had docking scores even greater than that of nocloprost, indicating that these compounds could have potential cytoprotective (anti-ulcer) activity. A few correlations between docking score and substituents on the prostaglandin skeleton were found. Full article

Different activity of compounds with the same molecular formula but possessing alternative bonding arrangement or orientation of atoms in space is a very important issue when constructing molecules that can selectively interact with certain domains of the biological target. Herein, we present the synthesis of the new chiral benzisoselenazol-3(2H)-ones substituted on the nitrogen atom with three monoterpene moieties: p-menthane, pinane and carane. All derivatives were obtained by the reaction of an appropriate amine with 2-(chloroseleno)benzoyl chloride. The applied terpenyl amines were first synthetized by a multistep procedure starting from the corresponding alcohol (p-menthane system) or alkene (pinene and carene systems). Finally, all compounds were tested as antioxidants and antiproliferative agents on breast cancer MCF-7 and human promyelocytic leukemia cell line HL-60. The correlation between the structure of the obtained organoselenium compounds, representing examples of various isomers including enantiomers, diastereoisomers and regioisomers, and their bio-activity was thoroughly evaluated. Full article

The objective of the current study was to develop novel compounds–memantine derivatives with antimicrobial activity designed for application in treatment of bacterial and fungal infections in patients suffering from Alzheimer’s disease. To realize this objective, a series of six memantine hybrid molecules were synthesized, characterized by ¹H NMR, ¹³C NMR, MS, X-ray, and tested for their biological properties as anti-Alzheimer agents and their antimicrobial potential. Full article

The synthesis and characterization of three new bis 1-substituted 1H-tetrazoles are described. Two products were synthesized in a single step via a direct heterocyclization of primary amines, methyl orthoester (trymethyl orthoformate), and sodium azide in 30% and 91% yields, respectively. Besides, another one was prepared via a three-step synthetic strategy: S_NAr (32%), nitro-group reduction (66%), and primary amine heterocyclization (83%), yielding 18%, overall. The aim behind the synthesis of new tetrazole-containing products is to construct novel MOF-like structures to evaluate their gas capture properties (CO₂, CO, and SO₂) under relative humidity conditions. Full article

A New benzylidene derivative namely benzylidene-5-phenyl-1,3,4-thiadiazol-2-amine (BPTA), was successfully synthesized and characterized using Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance and elemental analysis (CHN) techniques. The inhibition efficiency of BPTA on mild steel corrosion in 1.0 N HCl was tested at various temperatures. The methodological work was achieved by gravimetric method complemented with morphological investigation. The concentrations of inhibitor were 0.1, 0.2, 0.3, 0.4 and 0.5 mM at the temperatures 303, 313, 323 and 333 K. The BPTA, molecules as become superior corrosion inhibitor with 92% inhibition efficiency of mild steel coupon in the acidic environment. The inhibition efficiency increased with increasing concentrations of BPTA and the excellent efficiency was performed with the 0.5 mM concentration and followed with 0.4 mM. In acidic environment, the 0.5 and 0.4 mM gave the optimum performance with weight loss technique and scanning electron microscopy analysis. On the other hand, the inhibition efficiency decreased with the increase of temperature. Results of BPTA indicated mixed type inhibitor and the adsorption on the mild steels surface obeys the Langmuir adsorption isotherm. It was found that the BPTA performance depend on the concentration and the solution temperature. Quantum chemical calculations have been done to correlate the electronic characteristics of BPTA with the corrosive inhibitive impact. Experimental and theoretical results are in good agreement. Full article

In this work, the necessity of synthesis of 1,3-di(hetero)aryl-7-substituted pyrenes is presented based on the results of theoretical calculations by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) by using Gaussian 09 program with B3LYP exchange-correlation functional and 6-31G** basis set. What is more, the synthetic routes with feasible reagents and conditions are presented. The subject of theoretical considerations are two pyrene derivatives which contain at position 1 and 3 pyrazolyl substituents and at position 7 amine (1) or boron (2) derivative. The theoretical calculations were also performed for the osmium complexes with mentioned ligands (3 and 4). The influence of electron-donating/accepting character of the substituent at position 7 of pyrene on the properties of molecules has been established. Full article

In this study, a series of nine 3-hydroxynaphthalene-2-carboxanilides, disubstituted on the anilide ring by fluorine, chlorine and bromine in various positions, was prepared by microwave-assisted synthesis and characterized. The compounds were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. The PET-inhibiting activity of the compounds was within a wide range, but rather moderate; the highest activity within the series of the compounds was observed for N-(3,5-difluorophenyl)-3-hydroxynaphthalene-2-carboxamide (IC₅₀ = 9.8 µM). The compounds were found to inhibit PET in photosystem II. Full article

Nowadays, water pollution due to heavy metal ions is a great concern in all human communities. In this project, a metal-organic frameworks (MOFs), which were named Zn₂(oba)₂bpy, (1; H₂oba = 4,4-oxybisbenzoic acid and bpy = 4,4-bipyridine) linkers, were successfully synthesized. The properties of these MOFs were investigated using different techniques, such as FT-IR, XRD, and SEM analysis. The frameworks have special characteristics, like the rapid, efficient, and selective removal of metal ions from contaminated water. The use of an ultrasonic device plays an important role in shortening the absorption time of mercury (II) ions by increasing absorbent dispersion in the solution. The adsorption capacity was affected by variables such as the pH of the solution, Hg²⁺ initial concentration, adsorbent dosage, and contact time. For Hg(II) metal ions, the sorption capacity of 338 mgg⁻¹ was effectively obtained by Zn₂(oba)₂bpy structures. The experimental adsorption data for the Zn₂(oba)₂bpy MOF is well-suited to the pseudo-second-order kinetic model (R² = 0.99), and the adsorption isotherms of Hg²⁺ metal ions are in good agreement with the Langmuir model. This work displays the effective removal of Hg²⁺ ions from pollutant water in under 30 min. The antibacterial activities of Zn₂(oba)₂bpy (1) were tested against gram-positive and gram-negative species. The as-synthesized 1 exhibited excellent antibacterial effectiveness against Escherichia coli and Staphylococcus aureus. Full article

The present study focuses on the microwave assisted extraction of Annona reticulata leaves in ethanol. The extract obtained was subjected to column chromatography and the fractionation was done to get different fractions. Preliminary phytochemical screening was done and the fractions were subjected to total phenolic and flavanoid content estimation. The crude extract contained 502 mg GAE/100 g of phenolic content and among the fractions AM8 contained the maximum amount of phenolic content that is 360 mg GAE/100 g. The flavanoid content present in the crude extract of the Annona reticulata was found to be 127 mg QE/100 g. Among all the tested fractions, the fraction AM8 showed more flavanoids i.e., 112 mg QE/100 g and 118 AN/100 g. The antioxidant activity has been studied in-vitro by using DPPH, hydrogen peroxide assay. DPPH, H₂O₂ and Nitric-oxide scavenging effect of Annona reticulata L. leaf extracts were found to be dose dependant with maximum inhibition at highest concentration. Methanolic extract of the leaves of Annona reticulata Linn. is found to have most potent anti-oxidant activity in DPPH, H₂O₂ Radical scavenging methods. IC50 value DPPH and H₂O₂ inhibition of methanolic extract at highest concentration (400 μg/mL) are 62.58 ± 1.15, 68.27 ± 1.05 and 64.01 ± 1.02. The results suggest that all the tested extracts are having antioxidant property, but the methanol is having significantly higher flavonoid and phenol content. Due to presence of higher flavonoid and phenol content in methanol, it may be considered as the fraction with better pharmacological property in comparison to other tested extracts. Full article

The intermolecular quenching between 5-(2′-aminoethyl)aminonaphthalene sulfonic acid (Edans) and 4-[[4′-(N,N-dimethylamino)phenyl]diazenyl]benzoic acid (Dabcyl) was studied by photometric and fluorimetric measurements at pH 7.5 in phosphate buffer. The spectral properties of the Edans/Dabcyl donor–acceptor pair were determined and Dabcyl exhibited an intense absorption band at 463 nm, contributing to the quenching efficiency. We also found the primary requirement for fluorescence resonance energy transfer (FRET), the excellent overlap between the fluorescence emission spectrum of the donor molecule and the absorption spectrum of the acceptor molecule, resulting in efficient energy transfer. The quenching mechanism was studied using the Stern–Volmer plot, confirming that this FRET pair was involved in a dynamic quenching process. Full article

The development of a new generation of electrospun polymeric materials designed to accomplish multi-performance in a bioinspired integrated system represents the main goal of the present research. Polysulfones promise to become such nanosized fibrous structures with attractive properties associated with biomedical applications by the development of a new “construct”. Therefore, the homogeneous solutions of the functionalized polysulfones with quaternary ammonium groups (PSFQ) dissolved in various solvents were processed by electrospinning to create polymeric scaffolds that can modulate cellular behavior. Additionally, the antibacterial activity of PSFQ fibers against Gram-negative and Gram-positive bacteria has indicated the potential of these scaffolds for biomedical use. Full article

The present study was conducted to test for in vivo Brine Shrimp Lethality Assay (BSLA) of the Aqueous and ethanolic extracts Annona reticulate Linn. and Allium sativumand correlate cytotoxicity results with known pharmacological activities of the plants. Cytotoxicity was evaluated in terms of LC50 (lethality concentration). Ten nauplii were added into three replicates of each concentration of the plant extract. After 24 h the surviving brine shrimp larvae were counted and LC50 was assessed. Results showed that the presence of alkaloids, tannins, and flavonoids could be accounted for its cytotoxic properties. In the other hand, studies have shown that the leaf extracts of Alcoholic and aqueous extract of Annona reticulata and bulbs of Allium sativum extracts exhibited cumulative activity when they were combined and compared. Thus, the results on the leaf extracts of Alcoholic and aqueous extract of Annona reticulata and bulbs of Allium sativum exhibited increase in activity support its use in traditional medicine. Full article

Phenolic antioxidants are used in the industry to delay the oxidation of fats, with the most used being butyl hydroxy anisole (BHA) and butyl hydroxy toluene (BHT). However, the consumer concern regarding their safety has motived the study of natural alternatives. In this sense, the aim of this work was to evaluate the behavior of 3,3′-dimethoxy-5,5′-di-2-propenyl-1,1′-biphenyl-2,2′-diol and 6,6′-dihidroxi-5,5′-dimethoxy-(1,1′-biphenyl)-3,3′-dicarbaldehyde free and supported on mesoporous alumina. Biphenolic compounds were synthetized by radical coupling and then anchored on alumina by microwave assisted process. The antioxidant activity of these compounds was investigated by phosphomolybdenum method. The results showed that biphenolic compounds anchored on mesoporous alumina have a marked antioxidant activity, better than free antioxidants. Biphenolic compounds supported on alumina display antioxidant properties allowing a new opportunity for the developing in food and cosmetics packaging. Full article

We present here a new proposal for the “one pot” generation of new 4-thiazolidinones (9a–e) through a multicomponent reaction under microwave irradiation conditions, using aromatic and heteroaromatic amines (8a–e), absolute ethanol as a “green” solvent and modifying the aldehyde group in the glycosidic residue, synthesized from D-mannitol. The study is focused in the variation of the irradiation times and the concentration of thioglycolic acid in order to study the possibility of controlling the structure and/or stereochemistry of the products formed in the reaction. Thiazolidinones 9a–d were obtained with a 69–82% The generation of the corresponding reaction products were monitored by TLC and CG-MS, taking reaction aliquots. The conditions reaction proved to be chemoselective depending on the excess of acid and irradiation times. Full article

The isolation of water-soluble polysaccharides and proteins solubilized during the treatment of rye flour in an isotonic aqueous medium is described. Protein and polysaccharide assays of the aqueous fractions showed the high extraction performance of these compounds. Then, nanoparticles were synthesized from these hydrophilic isolates using fluorescein as a model drug and sodium hexapolyphosphate as a cross-linker. The preparation process consisted of dispersion, desolvation, drug incorporation, crosslinking, and separation of nanoparticles. The physicochemical analysis revealed that nanoparticles were successfully synthesized with rye hydrophilic isolates using a desolvation method. These studies demonstrated that rye nanoparticles are a promising candidate as an active compounds vehicle system. Full article

A 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivative functionalized with a formyl group at position 2 was synthesized in 57% yield. The compound was characterized by ¹H and ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy and mass spectrometry. The photophysical characterization was carried out by means of absorption and fluorescence spectroscopies in acetonitrile solutions. The BODIPY derivative showed an absorption band at 492 nm and an emission band at 506 nm. A preliminary evaluation of the recognition ability of the BODIPY derivative was investigated in the presence of several cations with environmental and biomedical relevance. A highly selective colorimetric response was obtained for Fe³⁺. Full article

A single Neonicotinoids are considered to be one of the important classes of insecticides used at the present time. In this study the partial least squares (PLS) approach is applied to a series of nitromethylene, pyrrole- and dihydropyrrole-fused neonicotinoids to model their insecticidal activity (pLC50 values) against the cowpea aphids. The structures were modeled using the MMFF94s force field. A robust PLS model (3PCs, R²X(Cum) = 0.963, R²Y(cum) = 0.870 and Q²(Cum) = 0.796) with predictive power (CCC_ext = 0.873, r²_m = 0.680, Q²_F1 = 0.805, Q²_F2 = 0.802, Q²_F3 = 0.704) is obtained. New insecticides active against the cowpea aphids can be predicted. Full article

Chemical synthesis of carbohydrates is a challenging task. Several protection and deprotection steps of hydroxyl groups are required to ensure regioselective formation of the glycosidic bond. Usually, it is achieved through acylation, where conventional heating is combined with addition of Lewis acids as catalysts. This traditional approach has two drawbacks; it is time consuming and often catalysts are hazardous to the environment. An alternative route relies on application of microwaves and/or other Lewis acids with less or no toxicity. Such combination would reduce reaction times and offer a benign synthetic strategy to obtain peracylated compounds. The current work describes an efficient and environmentally mild synthesis of peracylated glycosides with potential application in enzymatic preparation of carbohydrates. Model compound O-perbutyrylated-phenyl-galactose was synthesized using imidazole as catalyst in the microwave-assisted process. The acylation protocol was optimized, and the target sugar was obtained at 50% yield after 1 h. In conclusion, the combination of imidazole and microwaves provides an excellent alternative to swiftly synthesize peracylated glycosides in a benign way. Full article

In recent years, heterogeneous semiconductor photocatalysts have attracted great attention in the arena of environmental remediation and solar energy conversion; because, sunlight energy is a renewable, cheap, and accessible source of energy and also converting solar energy to chemical energy can be declined the energy crisis and global warming. Development of visible light heterogeneous photocatalysts with high efficiency and chemical stability is important for catalysis researchers. Among different types of semiconductor material, polymeric graphitic carbon nitride (g-C₃N₄) with a medium band gap of about 2.7 eV has been widely applied in photodegradation of organic pollutants, water splitting, CO₂ reduction, solar cells, energy storage, and organic synthesis. Unfortunately, due to the high rate recombination of photoinduced carriers, the photocatalytic performance of the bare g-C₃N₄ is still poor. Hence, many strategies including metal doping, noble metal deposition, and coupling with semiconductor composites have been employed to modify g-C₃N₄. Herein, we report the synthesis of g-C₃N₄/CuWO₄ nanocomposite via a hydrothermal process. The prepared visible-light-driven nanocomposite exhibited an enhanced photocatalytic activity compared with bare g-C₃N₄ for the degradation of methylene blue (MB) under LED light irradiation. Full article

Integration of nanomaterials is an entirely new method to synthesis efficient catalysts. These compounds provided new characteristics and distinctive application which is not accessible in the single-particle nanostuctures. Although there is little catalytic activity in each component of the hybrid material, their hybrid displays much higher activity. Indeed, the presence of intermediate metal and their oxides in the framework of hybrid catalyst caused a synergistic effect, thus facilitate the organic reaction more effectively. The extensive biochemical and pharmacological activities of imidazole-containing compounds have required the development of efficient methods for synthesizing these compounds, which is a significant topic in organic chemistry. The imidazole nucleus function as a main scaffold for constructing of biologically important molecules. The ZnS/CuFe₂O₄ magnetic hybrid nanocatalyst was synthesized by a simple co precipitation and characterized by conventional analyses successfully. Synthesized nanocomposite was utilized as a magnetic and heterogeneous catalyst for the one-pot synthesis of 2,4,5-triaryl-1H-imidazole derivatives with condensation of various aromatic aldehydes, benzil and ammonium acetate. The presented method shows some advantages such as mild conditions, good yields, and simple separation of products from the reaction mixture and cost-effective catalyst. The experimental data showed ZnS/CuFe₂O₄ nanocatalyst were easily separated from the reaction mixture using an external magnetic field and use again five times in subsequent reactions without appreciable reduction in catalytic activity. Full article

Widespread secondary plant metabolites (betulinic, ursolic, and oleanolic acids) are promising scaffolds for the discovery of new drugs. Among the many semi-synthetic derivatives of lupane triterpenoids known today, the anticancer agent C-28 ester of betulinic acid with tris(hydroxymethyl)aminomethane (NVX-207) has been actively studied. This betulinic acid derivative, which has shown significant antitumor activity in vitro and in vivo against various malignant tumors, is a candidate drug. It is known that modification of the structure of the triterpenoid skeleton can lead to significant changes in biological properties. In this regard, we have synthesized C-28 esters of ursolic and oleanolic acids and C20-29 hydrogenated betulinic acid bearing tris(hydroxymethyl)aminomethane (TRIS), and transformed them into guanidinium salts by guanylation of the primary amino group in a branched ester fragment under the action of 1H-pyrazole-1-carboxamidine hydrochloride. The obtained compounds were tested in in vitro experiments on three human cancer cell lines. The presence of the TRIS-fragment in the triterpenoid conjugates markedly enhanced the cytotoxic action as compared to the parent compounds, dihydrobetulinic, ursolic, and oleanolic acids (IC₅₀ values 2.8–7.6 μM for Jurkat cells and 1.1–6.8 μM for U937 cells), while the correlation between the cytotoxic activity and the chemical structure of the triterpenoid skeleton was not observed. Extended biological testing of these triterpenoids by using flow cytometry analysis showed that antitumor activity of compounds is caused by apoptotic processes and induction of cell cycle arrest in the S-phase. New triterpenoids were also tested for their antimicrobial activity against the growth of four bacterial strains (Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus (MRSA)) and two fungal strains (Candida albicans and Cryptococcus neoformans). The TRIS-dihydrobetulinic acid conjugate and its guanidinium derivative did not exhibit antimicrobial properties. The corresponding ursane and oleane-skeleton pentacyclic tritrerpenoids showed good bacteriostatic activity against methicillin-resistant S. aureus (MICs 4 and 32 μg/mL) and excellent antifungal effect against Cryptococcus neoformans and Candida albicans (MICs 4 and 0.25 μg/mL). Full article

The present study was conducted to test for in vivo Brine Shrimp Lethality Assay (BSLA) of the Aqueous and ethanolic extracts of Annona reticulata with Allium fistolisum and Brassica oleraceaeand correlate cytotoxicity results with known pharmacological activities of the plants. Cytotoxicity was evaluated in terms of LC₅₀ (lethality concentration). Ten nauplii were added into three replicates of each concentration of the plant extract. After 24 h the surviving brine shrimp larvae were counted and LC₅₀ was assessed. Results showed that the extracts of Annona reticulata with Allium fistolisumand Brassica oleraceaewere potent against the brine shrimp when compared alone with combined extracts. It indicated that bioactive components are present in these plants that could be accounted for its pharmacological effects. Thus, the results support the uses of these plant species in traditional medicine. Full article

Drugs of abuse are small molecules that typically do not induce an antibody response following the administration. To induce antibodies against these kind of molecules, structural changes have to be made to obtain so called “haptens”. The hapten must be coupled to immunogenic proteins, called “carriers”. These connected derivatives are typically drug-linker adducts, in which the linker has a terminal functional group (i.e., carboxylic acid or aliphatic amine) that forms a covalent bond with the carrier. The efficacy of these conjugate vaccines depends on several factors including hapten design, coupling strategy, hapten density, carrier protein selection, and vaccine adjuvant. Six nor-normorphine compounds were reacted with ethyl acrylate and ethyl bromoacetate. After the synthesis of the specific esters we hydrolyzed them to receive the N-carboxymethyl- and N-carboxyethyl-normorphine derivatives. The next step was the coupling phase with glycine ethyl ester, but the reactions didn’t work or the work-up process was not accomplishable. As an alternative route the normorphine-compounds were reacted with N-chloroacetyl glycine ethyl ester. These products were hydrolyzed in alkaline media and after the work-up process all of the derivatives contained the free carboxylic group of the glycine sidechain. All of the glycine ester and the glycine carboxylic acid derivatives are under biological tests. Full article

Heterocyclic compounds play an important role in medicinal chemistry and occupy a central position in synthetic organic chemistry. Both benzofuran and benzothiophene are considered as very important structures due to their diverse biological and pharmacological profile. Many clinically approved drugs are synthetic and naturally occurring substituted benzofuryl and benzothiophenyl derivatives in conjunction with other heterocycles. Therefore, a new series of α-amino ketone (containing various azole rings) derivatives of benzofuran and benzothiophene are synthesized and subjected to the transfer hydrogenation with formic acid, catalyzed by RhCl[(R,R)-TsDPEN](C₅Me₅). The corresponding optically active β-amino alcohols are obtained in high yields and excellent enantioselectivities (93%–99%), as determined by chiral HPLC (high-performance liquid chromatography). The absolute configuration of the products is confirmed by means of ECD (electronic circular dichroism) spectroscopy, supported by theoretical calculations. Full article

Pyrrolocarbazoles are important structural motives present in many natural products and pharmaceuticals. Particularly, pyrrolo [3,4-a] carbazole-1,3-diones have attracted much attention as analogues of bioactive compounds, such as anticancer agent granulatimide. Surprisingly, only a few methods for the synthesis of these compounds have been reported in the literature, and they are almost limited to the Diel–Alder cycloaddition of 3-vinylindoles. We have recently developed a multicomponent synthesis of polysubstituted anilines starting from ,-unsaturated carbonyls, isocyanides and dienophiles. Here we report the application of this tandem [4 + 1]–[4 + 2] cycloaddition procedure for the synthesis of 4-amino-5-arylisoindoline-1,3-diones, which are then cyclized by means of a metal catalyzed intramolecular C-N coupling, affording structurally diverse, natural product-like pyrrolo [3,4-a] carbazole-1,3-diones with high yields and selectivities. Full article

The activated carbon was prepared from an almond shell, which is chemically activated by H₂SO₄. In the present study, the adsorption of rhodamine-B from water by activated carbon has been investigated and compared. The effect of pH value, initial concentration of dissolved and amount of adsorbent on the adsorption of rhodamine-B by the mentioned adsorbents were investigated. Results showed that the adsorption process was highly dependent on pH. Maximum rhodamine-B removal was achieved when the final pH is 11. Maximum rhodamine-B removal efficiencies were obtained by an almond shell (70%). Adsorption test results revealed that rhodamine-B adsorption on the studied adsorbents could be better described by Langmuir isotherm. Full article

Organomagnesiumoxane alumoxane siloxane oligomers with different Al:Mg and Al:Si molar ratio have been synthesized through ethylacetoacetate alkoxyhydroxyalumoxane oligomers co-condensation with magnesium acetylacetonate and oligoethoxysiloxanes in organic solvents (alcohol, toluene) at a temperature of 70–100 °С within 3–6 h with the following solvent distillation. The physicochemical properties of the synthesized oligomers were studied. It is shown that with a molar ratio of Al:Mg ≈ 2 and Al:Si ≈ 1, oligomers have fiber-forming properties. The process of thermotransformation of organomagnesiumoxane alumoxane siloxanes into ceramic phases is investigated. It is found that pyrolysis results in the formation of multicomponent ceramics based on magnesium, aluminum, and silicon oxides, in particular, ceramics with a composition close to that of cordierite 2MgO·2Al₂O₃·5SiO₂ (Mg₂Al₄Si₅O₁₈) or a mixed composition: magnesium-aluminum spinel and mullite. Therefore, the synthesized organomagnesiumoxane alumoxane siloxanes are preceramic oligomers and can be used as precursors for the preparation of various components (binders, impregnating compositions, fibers, ceramic powders) of high-purity ceramic composites based on magnesium, aluminum and silicon oxides. Full article

C*-BODIPYs, that is, boron dipyrromethenes (BODIPYs) which have chiral carbons attached directly to the boron center, are introduced for the first time. These novel chiral BODIPYs mean a new strategy for the chiral perturbation of the inherently achiral BODIPY chromophore that is directed to enable chiroptical properties. Their preparation is very simple and only implies the complexation of a dipyrrin with an enantiopure dialkylborane having boron bonded to chiral carbons. Full article

A new N-boron dipyrromethene (N-BODIPY) substituted with a crown ether moiety has been synthesized by reaction of an F-BODIPY with a crown-ether-substituted bis(sulfonamide). The workability of this N-BODIPY as an off/on sensor for cations by modulation of a photoinduced electron transfer (PET) is explored. The new N-BODIPY demonstrates the possibilities of functionalization of these still unexplored but promising dyes. Full article

Ionic liquids are synthetic compounds with melting temperatures lower than 100 °C and with high ability of modification of their physical and chemical properties from changes in their chemical structure. Although the number of applications in the last years has been continuously increasing, their effects on the different terrestrial ecosystems have been scarcely studied. In this work, the effects of the ionic liquid ethylammonium nitrate (EAN), the aluminum nitrate salt (Al(NO₃)₃), and the saturated mixture of both components on the germination of three forest species were studied. Different doses, from 0% to 10% weight, of the three treatments were applied at seeds of three different forest species (Eucalyptus globulus Labill, Pinus radiata D. Don, and Pinus sylvestris L.) and the germination of these seeds was continuously monitored for 35 days. The results showed that the addition of ionic liquid, salt, and mixture provoke the reduction of germination for all the species. Concentrations of 5% and higher incite the total inhibition of the germination of all species for all the treatments, with the EAN treatment being the most harmful. Full article

Current electrolytes for electrochemical energy storage devices are made of solvents, which often present problems of flammability, corrosion and high toxicity. Ionic liquids and mixtures with metal salts are proposed as a good selection for safer electrolytes due to their properties such as, among others, non-flammability, negligible vapor pressure, high ionic conductivity and wide electrochemical window. In this work, the electrical conductivity of solutions of the ionic liquid 1-ethyl-3-methylimidazolium nitrate ([EIm][NO₃]) with lithium nitrate salt in three different concentrations is analyzed for liquid and gel states. The temperature and salt concentration dependences of electrical conductivity are studied for liquid and gel states. As expected, an increase in conductivity with temperature and a decrease with salt concentration were observed, except for the case of gel [EIm][NO₃] with a salt concentration of 0.5 m, which shows a small increase in conductivity compared to the pure gel. Comparison of the conductivity of the liquid and gel states shows a significant increase for the gel state at low concentrations of the added salt. Full article

The ionic liquids (ILs) doped with metal salts have become a real alternative as electrolytes for batteries, but the right choice of these compounds for reaching the adequate properties and performance is still a challenge, and strategies are therefore needed for achieving it. The thermophysical properties of IL 1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide ([bmpyr] [TFSI]) and its mixture with bis-(trifluoromethane)-sulfonimide lithium salt (from 0.1 m to saturation level) were determined in this work. These properties are density (ρ), speed of sound (U), and corresponding derived magnitudes, such as the bulk modulus and the thermal coefficient, as well as electrical conductivity (σ) against temperature. Density shows a linear decreasing dependence with temperature and a clear increase with the addition of salt, whereas the thermal expansion coefficient increases with temperature and salt addition. Speed of sound decreases with both temperature and salt concentration, and the adiabatic compressibility calculated by means of the well-known Laplace equation increases, as expected, with temperature in all the studied cases, although a small variation with concentration was observed. Electrical conductivity increases with temperature following the Vogel–Fulcher–Tammann (VFT) equation and decreases with the addition of salt. Full article

We report herein a study on the Ag/Cu-catalyzed reactivity of α-allenols. The focus was the development of new methodologies for cyclization and/or transposition of this moiety. By simple solvent switch, the divergent preparation of dihydrofurans and 3-halo-3-alkenals in a controlled manner has been reached. Full article

In this study, halloysite nanotubes (HNTs) are modified by chitosan as a natural cationic amino polysaccharide. Halloysite nanotubes/chitosan (HNTs/Chit) were characterized by Fourier transform infrared (FT-IR) spectroscopy and energy dispersive X-ray (EDX) analysis. Also, its performance as a heterogeneous catalyst was investigated in the synthesis of pyranopyrazole derivatives. Being a reusable and easily recoverable catalyst, eco-friendliness, high efficiency, and mild reaction conditions are some advantages of the present work. Full article

In this study, a terephthalate and pyrazine-based metal–organic framework (MOF) was prepared using the oxygen and nitrogen donor ligands through the hydrothermal method. In the MOF, cobalt and nickel ions were selected as metal nodes which are connected by terephthalate and pyrazine linkers. The as-prepared MOF was utilized as Cr adsorbent in water by an ultrasonic method. The MOF capacity towards chromium ion adsorption was obtained about 96% in 50 ppm initial concentration. In order to characterize and determine the morphology of the title MOF, the FT-IR and XRD methods were applied, while the chromium concentration before and after adsorption was determined by the ICP method. Full article

Metal−organic frameworks (MOFs), which are porous materials that are prepared from metal ion/clusters and multidentate organic ligands, have evolved to be next generation utility materials because of their usability in diverse applications. MOFs, as a class of interesting materials, have attracted great attention due to their controllable pore size and elaborately designed pore structure. In the past two decades, MOFs have exhibited versatile potential applications such as gas storage, gas separation, heterocatalysis, sensors, and luminescence. Most research works so far have focused on MOFs based on transition metal ions or rare-earth ions. In this review, a porous Ba (II)-based MOF was synthesized with an ultrasonic method by using benzene-1,2,4,5-tetracaboxylic acid as an organic linker; this was characterized by X-Ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy methods. Full article

Isosorbide is a competitive starting material for various valuable derivatives by functionalization and/or substitution since it is a renewable and carbon neutral material that is produced on an industrial scale from sorbitol. A set of O-alkyl- or O-arylated beta-iodo ethers has been synthesized from isosorbide. The key step was the iodoetherification of isosorbide-derived glycals with a variety of oxygenated nucleophiles in the presence of N-iodosuccinimide. trans-Iodo ethers and acetate were obtained in good yields and the removal of iodide affords isosorbide derivatives. The usefulness of this new approach is illustrated by the synthesis of a surfactant having a dimer of isosorbide as hydrophilic group and by the preparation of a structurally unusual bicyclic anhydro carbohydrate. Full article

Monoterpenes are optically active compounds which occur in nature. This fact makes them interesting precursors for the synthesis of optically active ligands, which can be applied in various asymmetric reactions. In this work, we present the synthesis of optically pure 2-amino-apopinan-3-ol from (−)-α-pinene. The obtained amino alcohol was used as a precursor of oxazaborolidine, which was used as catalyst in the asymmetric reduction of aryl-alkyl ketones with borane. In the second part, we transformed 2-amino-apopinan-3-ol into PHOX ligand in a three-step reaction. The complex of ruthenium precursor with PHOX ligand was used as a catalyst in the asymmetric transfer hydrogenation of aryl-alkyl ketones. Alcohols with enantiomeric excesses of up to 97% were isolated using both reduction methods. Full article

A magnetic composite consisting of iron oxide and a cobalt–aluminum-layered double hydroxide, Fe₂O₃@Co-Al-layered double hydroxide was prepared through linking of Fe₂O₃ to Co-Al layered double hydroxide (LDH) by sodium acetate. Layered double hydroxides are generally described as [M²⁺_1–xM³⁺_x(OH)₂] [A_n–x/n·mH₂O], where M²⁺ and M³⁺ are divalent and trivalent metal cations, respectively, and A is an n-valent interlayer guest anion. The composite was characterized by XRD, FTIR and UV-Vis. spectroscopy methods. Afterwards, the composite was used for methyl-orange adsorption in aqueous solution. The UV–Vis spectrum indicates that the adsorption process was satisfying. In effect, after several washings of the composite, no decrease of the adsorption capacity was observed. Full article

Tetralactam macrocycles are suitable candidates to be employed as synthetic receptors for charged or neutral guests. In the sensing of neutral molecules, nonpolar solvents such as chloroform or dichloromethane are usually employed so the hydrogen-bonded interactions can be established. Thus, one of the main limitations of the studied macrocycles is their low solubility in those solvents. Herein, we describe the synthesis of an adamantane-based tetralactam macrocycle that is soluble in chlorinated solvents. For this purpose, by following a clipping methodology, we firstly synthesized a kinetically stable pseudorotaxane, constituted by a removable tetraalkylfumaramide thread and the desired macrocycle. A subsequent thermal dethreading straightforwardly yielded the adamantane-based macrocycle. Afterwards, the affinity of this receptor for a series of fumaramide and succinamide guests was studied, calculating the association constants when the corresponding [2]pseudorotaxanes are assembled. Full article

Plants have been used for centuries to treat diseases and are considered an important source of new antimicrobial agents. Plant extracts can be obtained and their composition determined, being widely employed in the pharmaceutical and cosmetic industries. A less explored and potential application is the use as green insecticides/insect repellents, as an alternative to current pesticides. Despite the desirable properties, many of the isolated components (phytochemicals) present limitations on their use, due to high volatility and easy degradation when exposed to air. Nanoencapsulation techniques arise as promising strategies to allow the preservation and controlled release of plant extracts. In this work, a series of plant materials, Phytolacca americana L., Tagetes patula L., and Ruta graveolens L., were subjected to Soxhlet extraction using various solvents and times of extraction. The extracts obtained were submitted to biological studies, to assess their potential against the insect cell line Sf9. Encapsulation assays in lipid nanosystems were carried out, with encapsulation efficiencies higher than 70%. Full article

A serie of novel 3-tetrazolylmethyl-4H-chromen-4-ones were synthesized via Ugi-azide reaction under mild ultrasound-assisted conditions (room temperature, EtOH, 10% mol ZnO nanoparticles). The products containing two privileged heterocyclic frameworks: 1,5- disubstituted-1H-tetrazole and 3-substituted-4H-chromen chromen-4-ones, which are present in a variety of bioactive compounds and commercial drugs Full article

We investigated electrochemical sensors based on graphite oxide (GrO) and oxidized carbon black (CbO). GrO and CbO were synthesized by the modified Hummers method. Single-stranded DNA (ssDNA) probes were synthesized with a 5′ primary amine for attachment. These ssDNA oligonucleotides were immobilized on GrO and CbO using standard 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) coupling. This formed an amide bond between the DNA-amine and carboxyl groups on GrO and CbO. GrO and CbO were used instead of graphite in a carbon paste material. This significantly enhanced the sensitivity of the biosensor for the reverse-complementary DNA. We detected reverse-complimentary DNA using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV) in a ferricyanide solution. The solution was spiked with the ssDNA oligonucleotide with the reverse-complementary sequence of the immobilized probe. The change in current or impedance was measured. We present early work on optimizing the fabrication method for DNA-functionalized carbon electrodes. Working electrodes were fabricated by drop-casting the active material onto a glassy carbon electrode surface. Full article

Noble metallic nanoparticles, silver (AgNPs) and gold (AuNPs) mainly, exhibit good antimicrobial, antibacterial, and antifungal properties and, therefore, have a significant contribution to the constant growing field of nanomedicine. They can be synthesized using both conventional or unconventional methods and, in the last decades especially, the unconventional routes that use plants as raw vegetal materials are studied with proven results. On the other hand, macrocyclic derivatives such as phthalocyanines (Pcs) have photoactive properties and numerous applications. The conjugation between silver and gold nanoparticles with phthalocyanine derivatives considerably increases both the photochemical activity of Pcs as well as the stability of noble metallic nanoparticles. This paper describes recent research in the field of green-synthesized AgNPs and AuNPs from different plants with important pharmacological applications in two different temperature conditions: at room temperature, for 12 h, and at 50 °C for 30 min. AgNPs and AuNPs then react with tetracarboxamido-zinc phthalocyanine ZnPc(CONH₂)₄ and octacarboxamido–zinc phthalocyanine ZnPc(CONH₂)₈ to obtain two hybrid nanoaggregates, confirmed by spectroscopic analyses and by determining their antioxidant and antimicrobial activity. Full article

In the present work, our objective is to take advantage of the property presented by Ionic Liquids (ILs) based on 1-alkyl-3-methylimidazolium cations by having amphiphilic character when the alkyl group is a long hydrocarbon chain. These ILs can act as surfactants forming micelles in aqueous solution. In this sense, the micellar effect on a Diels-Alder reaction (DA) was analyzed taken as a reference. The reactive system studied consists of maleic anhydride and isoprene, variables such as diene:dienophile ratio and reaction temperatura among the most important were optimized. N,N-dodecylmethylimidazolium bromide was used at the critical micellar concentration (CMC) of 1 × 10⁻² M. These “new systems” microheterogeneous would allow, in addition to better solubilization of non-polar substrates, to adopt milder reaction conditions. Full article

The composition of the repugnatorial secretion of some populations of the Cuban endemic millipede Rhinocricus inhabiting in the western region of the Cuban archipelago has been developed. Several quinonoids metabolites were identified. From some individuals (males), collected in forest and karst regions, 850 μg of a deep brown-red secretion were obtained, and directly introduced into analytical instrumental (GC-MS and FTIR). The analysis of FTIR and GC-MS spectra shows that major components of secretions are substituted hydroquinones, 1,4-benzoquinones and aldehydes. The biological effects of these defensive secretions were evaluated on pathogenic microorganisms, showing interesting antimicrobial action. The ecological and evolutionary significance of chemical differentiation in millipedes populations require further study. Full article

In this plan, we use Praseodymium metal-doped copper indium disulfide (Pr-doped CIS) heterostructure as hole-transporting materials (HTMs) in the FTO/TiO2/Perovskite absorber/HTM/ Au device. And photovoltaic performance of these Pr-doped CIS heterostructure was investigated in the fabrication of the organic-inorganic perovskite solar cells (organic-inorganic PSCs). Full article

The Ugi four-component reaction is versatile multicomponent reaction for generation of complex diversity, herein, we developed a novel methodology by using 4-((1-((tetrahydrofuran-2-yl)methyl)-1H-1,2,3-triazol-4-yl)methoxy)benzaldehyde as one of the components in Ugi 4CR that contains 1,2,3-triazole moiety which is a privileged molecule in medicinal chemistry to obtain Ugi adducts under room temperature ionic liquids as medium of solvent, then followed SN₂ pathway cyclization to get triazole containing 2,5-diketopiperazine derivatives in good yield using basic ionic liquids as a catalyst. Full article

A series of six new alkyne-2-chloroquinolines were synthesized in moderate yields (40%–65%) via the Passerini three-component reaction (P-3CR) under mild green conditions. The P-3CR takes place when a carboxylic acid, an oxo compound (aldehyde or ketone), and an isocyanide react to give α-acyloxy carboxamides. Recently it has been reported that small molecules containing alkynes promote interactions with different proteins in cells facilitating the detection or identification of protein targets. Full article

Adenine complexes were prepared with some of the first series transition metals in a stoichiometric ratio of 1: 2 (Mⁿ⁺: L), where Mⁿ⁺ = Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, and Cd²⁺ ions. The Complexes were characterized by the physicochemical and spectroscopic techniques as electric conductivity, metal contents, IR, UV–Visible, and molar conductance techniques. The stoichiometric ratios of the synthesized complexes were confirmed by using molar ratio method. The dissociation constant of adenine ligand was determined spectrophotometrically. Solvent effect on the electronic spectra of the adenine ligand was examined using solvents with different polarities. The biological activity of adenine ligand and its metal complexes were tested in vitro against some selected species of fungi and bacteria. The results showed a satisfactory spectrum against the tested organisms. Full article

Currently, the plastic packaging industry in Brazil is the second largest producer in the packaging sector, with approximately 35% of the total packaging produced per year. Out of this total, 572 thousand tons are composed of polyethylene terephthalate plastic bottles (PET). In the ranking of the main materials discarded in the country, plastic occupies the third position and, in most cases, inadequately. Objectifying minimizes the amount of PET packaging improperly discarded and to instigate the industrial interest in the subject, our work pursued a viable path, as clean as possible in the principles of Green Chemistry, to depolymerize it. Obtaining the terephthalic acid as the main product, which is commercially obtained by oil sources and using salts and oxide of zinc as catalyzers in water as solvent, besides using inorganic bases as catalyzers in alcohols as solvent, including glycerol, which is a sub product of Biodiesel Industries. The reactions were made by refluxing (traditional way) and by microwave, where was used the reactor Biotage Initiator Plus. The products were characterized by Fourier Transformed Infrared Spectroscopy (FTIR of Bruker) and Ultra Performance Liquid Chromatography with Mass Spectrometer with Electrospray Ionization (UPLC-ESI/MS), where the results were better while using zinc sulfate as catalyzer in water and potassium hydroxide as catalyzer in pentan-1-ol. Full article

We present microwave-assisted synthesis and in vitro acetylcholinesterase inhibition of di-PRLC₄OAzo, a new azoderivative designed on the basis of aza-stilbene active compounds, already reported by the group. From the total series of azoderivatives synthetized, di-PRLC₄OAzo showed the powerful in vitro enzymatic response for its (E) isomer (IC₅₀: 1.08 µM) by Ellman’s assay, beside a stable photostationary state monitored by UV/Vis absorption spectroscopy, indicating it might be an efficient photo-responsible probe to remote control the activity of the enzyme. Full article

Bimolecular nucleophilic substitution (S_N2) reaction is one of the most frequently processes chosen as model mechanism to introduce undergraduate chemistry students to computational chemistry methodology. In this work, we performed a computational analysis for the ionic S_N2 reaction, where the nucleophile charged (X⁻; X=F, Cl, Br, I) attacks the carbon atom of the substrate (CH₃Cl) through a backside pathway, and simultaneously, the leaving group is displaced (Cl⁻). The calculations were performed applying DFT methods with the Gaussian09 program, the B3LYP functional, the 6-31+G* basis set for all atoms except iodine (6-311G*), and the solvents effects (acetonitrile and cyclohexane) were evaluated with the PCM model. We evaluated the potential energy surface (PES) for the mentioned reaction considering the reactants, the formation of an initial complex between the nucleophile and the substrate, the transition state, a final complex where the leaving group is still bound to the substrate and the products. We analyzed the atomic charge (ESP) and the bond distance throughout the process. Gas phase and solvent studies were performed in order to analyze the solvation effects on the reactivity of the different nucleophiles. We observed that increasing solvent polarity, decreases reaction rates. On the other hand, we thought it would be enriching, to carry out a reactivity analysis from the point of view of molecular orbitals. Therefore, we analyzed the MOs HOMO and the MOs LUMO of the different stationary states on PES, both in a vacuum (gas phase) and in acetonitrile as the solvent. Full article

Beetroot (Beta vulgaris L.) was subjected to extraction procedures in order to obtain the respective extracts containing the natural dyes and subjected to cytotoxicity assays in AGS cell line. Encapsulation of the extracts in nanosystems based on soybean lecithin and maltodextrin was performed. Lyophilized extracts before and after encapsulation in maltodextrin were applied in the formulation of leg ham and used in pilot scale of production. The colour of ham samples from the different assays was evaluated visually and by colorimetry. Full article

In this study, a novel porphyrin-based metal–organic framework (Co-Por MOF) was successfully synthesized by a simple one-step solvothermal method. We report a metal–organic framework based on the covalent interaction of an organic linker, 5,10,15,20-tetrakis(4-carboxyphenyl) porphyrin (TCPP) with cobalt clusters. The properties of this material were analyzed by powder X-ray diffraction (XRD), ultraviolet visible adsorption spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FTIR), and differential reflectance spectroscopy (DRS). Full article

Metal-organic frameworks are a class of attractive materials for fluorescent sensing. Here, we report the exploration of fluorescent Zn-based amine/azine-functionalized MOF, TMU-17-NH₂, ([Zn(NH₂-BDC)(4-bpdb)].2DMF; NH₂-BDC = amino-1,4-benzenedicarboxylic acid, 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-2,3-butadiene) for highly selective and sensitive detection of Fe³⁺ in DMF (N,N-dimethylformamide) solution. TMU-17-NH₂ shows fast recognition of Fe³⁺ ions with a response time of <1 min and detection limit of 0.7 µM (40 ppb), and the luminescence is completely quenched in 10⁻³ M DMF solution of Fe³⁺. Furthermore, no interferences from 250 μM As³⁺, Cd²⁺, Zn²⁺, Co³⁺, Ni²⁺, Cu²⁺, Pb²⁺, Mn²⁺ and Al³⁺ were found for the detection of Fe³⁺, which suggests that functionalized TMU-17-NH₂ is a promising luminescent probe for selectively sensing iron ions. Full article

The essential oils (EOs) from the leaves of Schinus areira and one of its components, globulol, were studied for their antioxidant, antimutagenic and antipromutagenic activities. The chemical composition of the EOs obtained using hydrodistillation was determined using gas chromatography-mass spectrometry (GC-MS), and fractionated using reversed phase high performance liquid chromatography (RP-HPLC). The active compound (16.61%) isolated was identified by comparison of its ¹H and ¹³C NMR spectroscopy with those reported in the literature. The antioxidant activity of the EOs and globulol were determined using two methods: crocin bleaching inhibition (Trolox Equivalent Value, TEV Krel = 1.16 ± 0.11 vs. 1.24 ± 0.22) and scavenging of the DPPH radical (IC₅₀ = 38.75 ± 2.5 μg/mL vs. 5.60 ± 0.9 μg/mL). The antimutagenic and antipromutagenic activities were evaluated in vitro and ex vivo, using the Ames assay with five strains of Salmonella typhimurium with and without exogenous metabolic activation (rat liver fraction S9), against different mutagens. The result determined that globulol and EOs of S. areira at the applied doses do not exhibit any mutagenic effect and showed the highest antioxidant activity. Full article