Please login first

List of accepted submissions

Show results per page
Find papers
  • Open access
  • 25 Reads
Synthesis and computational studies of eugenol based insecticides

Eugenol, a natural phenolic allyl benzene, have been used as active lead compound showing significant biological activities, namely as antimicrobial, antifungal and insecticidal on a wide variety of domestic arthropod pests.

Owing to the negative ambient impact and public health problems of synthetic conventional insecticides, less harmful alternatives are required in order to circumvent these inconveniences.

Considering these facts, in the present work ester eugenol derivatives were synthesized and evaluated for their insecticidal activities against the Spodoptera frugiperda cell line. Studies of structured-based inverted virtual screening were carried out in order to identify the potential targets associated to the obtained insecticidal activity.

  • Open access
  • 37 Reads
Phytochemistry of Uvaria narum: A multifaceted perspective and ethnopharmacological potential

The blooming ethnomedicinal plant Uvaria narum (Dunal) Wall is mostly found in the deep forests of the Western Ghats and belongs to the Annonaceae family. Uvaria narum is a spreading, pubescent shrub with large, dark bluish-green leaves. Phytochemistry and pharmacognostic studies have revealed that the plant contains a variety of phytochemicals that are both remarkable and beneficial to humans. The plant possesses a number of beneficial properties, such as antioxidant activity exhibited by the presence of polyphenols, and tannins, antifungal activity brought on by the benzoic acid moiety, and tumor-fighting abilities contributed by terpenoid and alkaloids. The presence of phytoconstituents in plants has been attributed to various medicinal properties, like anticancer activity. The plant may also be useful against aging and other diseases caused by free radicals. In vitro cytotoxicity is due to terpenoids, phytosterols, and flavonoids, whereas the liver is protected by flavonoids. The chemical profile of the plant shows that acetogenins, including stereoisomers, are important constituents of the root bark. Eczema, itching, varicose veins, haemorrhoids, jaundice, inflammation, and fever are the main ailments for which this herb is used.

  • Open access
  • 57 Reads
Exploring BINOL-O-BODIPY-based dimers as advanced chromophoric platforms enabling triplet state population

The development of chromophoric systems that populate triplet states upon light absorption, i.e. triplet state photosensitizers (TS-PSs), has great interest for many applications in diverse fields beyond Organic Photochemistry, such as Biomedicine (e.g., in singlet-oxygen-based photodynamic therapy, PDT, and phototheranosis) or Sustainable Energy (e.g., in photocatalytic water splitting). Despite the high fluorescence of the BODIPY (boron dipyrromethene) dyes, they can be suitable and valuable candidates as advanced TS-PS scaffolds, owing to their outstanding light-absorption capability and their tuneability by workable organic chemistry, as well as to the existence of well-known designing strategies to promote the required intersystem crossing (ISC) towards the TS. Among these strategies, the use of heavy atoms, such as iodine or heavy metals is one of the most used. However, these dyes usually suffer from the potential toxicity of said heavy atoms, limiting their application in Biomedicine. Another approach is based on the construction of orthogonal (directly-linked) BODIPY dimers, although this strategy is not general and usually requires complex syntheses. Additionally, modulating the population of intramolecular charge transfer (ICT) states in BODIPYs has emerged as a potential tool for designing TS-PSs, since ICT states can serve as runways promoting the ISC. Among these ICT-modulable-BODIPYs, two easily-accessible designs have been studied: meso-meso p-phenylene-bridged BODIPY-BODIPY dimers and BINOL-O-BODIPYs. In this context, we hypothesized that putting both designs together within the same molecule could be a potential strategy to boost triplet population in heavy-atom-free BODIPYs. This communication shows preliminary results related to this investigation, concerning the design, synthesis and photophysical characterization, including fluorescence and singlet oxygen generation, of the new dyes combining both features.

  • Open access
  • 36 Reads
1,4-Butane-sultone functionalized graphitic carbon nitride as a highly efficient heterogeneous catalyst for the synthesis of quinazolines derivatives

1,4-Butane-sultone functionalized graphitic carbon nitride (g-C3N4@Bu-SO3H) was prepared and applied as an efficient heterogeneous catalyst for the synthesis of various quinazoline derivatives with high yield. In next step, the structure and morphology of catalyst was characterized by different analyses such as, FT-IR, EDS, XRD and FE-SEM. On the other side, considering the noticeable features of g-C3N4@Bu-SO3H such as high stability, easy to synthesize, non-toxicity, excellent reusability, and so on, the synthesis of quinazolines derivatives with numerous advantages such as short reaction time, mild reaction condition, and easy separation were realized.

  • Open access
  • 20 Reads
The potential of thiazole derivatives as antimicrobial agents

The transnational concern to the healthy development of Human beings is antimicrobial resistance (AMR). It is seriously a big apprehension for Human life by the rising rates of microbial resistance, hence it is essential to find and create newer antimicrobial drugs with unique modes of action. All the heterocyclics creating hybrid compounds by fusing two or more bioactive heterocyclic moieties onto a single molecular platform is one approach to solving this colossal challenge. This study discusses the many hybrid approaches that have been used to produce possible novel antimicrobial medicines that are both safe and effective. The landscaping of heterocycles like thiazole derivatives is covered in the current review paper. In this paper, all the extensive approaches of heterocyclic composites, primarily thiazole derivatives, exhibit vibrant biological activity. The purpose of this work is to support the methods that may be used to create various thiazole derivatives and their biological activity. This paper will offer great recommendations for potential medicine designs in the future.

  • Open access
  • 18 Reads
Synthesis of N-heterocyclic carbene gold complexes using 2,4,6-trimethylphenyl sydnone as model substrate.

Sydnones are five membered heterocycles that belong to the class of dipolar compounds named "mesoionics" and represented as hybrids of several mesomeric/ionic forms. Their pka values are approximately 18, so they can be deprotonated with the appropriate base to give N-heterocyclic carbenes (NHC). These NHC can react with different gold precursors to obtain gold complexes. In this work the 2,4,6-trimethylphenyl sydnone was used as model substrate to synthesize gold complexes by a two-step reaction. This reaction is extremely sensitive to the presence of water thereby inert atmosphere is needed. The first reaction step was deprotonation of the sydnone with butillithium to obtain the corresponding NHC. In a second reaction step the metal precursor was added to afford the corresponding gold complex. At this point, the complex obtained depends on the nature of the metal precursor. A monocarbene complex (sydnone-Au-Cl) was obtained using AuthtCl as metal precursor. On the other hand, a biscarbene complex (sydnone-Au-imidazolium) was obtained using a gold imidazolium complex as metal precursor. The sydnone complexes were purified by precipitation or column chromatography and characterized by 1H-, 13C- and two-dimensional NMR, Fourier transform infrared (FTIR), UV Spectroscopy and elemental analysis. The 13C-NMR resonance frequencies of the carbene carbon atom are extremely shifted upfield from 97 to 139 ppm.

  • Open access
  • 29 Reads
Pyrano[3,2-c]chromenes characterization and evaluation of the antioxidant and antimicrobial activities
, , , , , , ,

Several studies have shown that the pyrano[3,2-c]chronenes moiety is a source of several molecules possessing interesting and considerable biological activities on the medicinal level, notably antimicrobial, anti-inflammatory, analgesic and anti-anxiolytic, anticancer activity. The main objective of this work is to evaluate the antioxidant and antimicrobial activities of pyrano[3,2-c]chronenes by using classical methods and more developed techniques.

Two series of pyrano[3,2-c]chromene derivatives have been prepared by synthetic and catalyst means, with an excellent yield which ranges between (90-96)% and then characterized via infrared and NMR analysis techniques.

The antioxidant activity was assessed using the DPPH method and by the power of iron reduction. The determination of antimicrobial activity was carried out against the reference bacteria.

The results of the antioxidant activity showed that both families of pyrano[3,2-c]chromenes have a reduction in DPPH radical and iron. While these families havea good antibacterial effect with inhibition areas ranging from 8 to 12 mm.

The results of antioxidant activity showed that both families of pyrano[3,2-c]chromenes showed a reduction in DPPH radical and iron. While these families have a good antibacterial effect with inhibtion areas ranging from 8 to 12 mm.

  • Open access
  • 28 Reads
Microwave activation in Fe-catalyzed reaction of Binor-S with nitriles

The classical method for the synthesis of N-substituted amides is the Ritter reaction of alcohols, haloalkanes, or olefins with nitriles and water catalyzed by H2SO4. The Ritter reaction can also be catalyzed by various Lewis acids based on salts of such transition metals as iridium, cobalt, copper, iron and niobium. Of particular interest is the Ritter reaction with cyclopropane derivatives. Only a few examples of such interaction are known. Thus, iron compounds, and in particular FeCl3*6H2O, catalyze the amidation of binor-S with a number of organic nitriles at a temperature of 140-150 oC during the reaction in an autoclave for 6 hours. We found that the catalytic system, consisting of 20 mol. % FeCl3*6H2O and 10 mol. % trifluoromethanesulfonic acid, with the simultaneous use of microwave irradiation allows to reduce the reaction time of binor-S amidation to 30 minutes with a simultaneous decrease in the reaction temperature to 80 ÷ 100 oC. In addition, it was possible to reduce the amount of excess organic nitrile used by a factor of four. Thus, for the first time, we have discovered the activating effect of catalytic amounts of trifluoromethanesulfonic acid and microwave irradiation on the reaction under study.

  • Open access
  • 22 Reads
TaCl5-catalyzed homo-coupling of disubstituted acetylenes under the action of EtAlCl2 and Mg
, ,

The reaction of homo-coupling of alkynes using zirconium- and titanium-containing reagents is an important basis for the efficient synthesis of polymer, oligomers and macrocycles. It is generally accepted that the homo-coupling takes place through the intermediate formation of “Cp2Zr” or “Cp2Ti” species that can be generated by the interaction of Cp2ZrCl2 or Cp2TiCl2 with alkali and alkaline earth metals, as well as with alkyl derivatives of metals. The most widely used reagents include Negishi reagent (“Cp2ZrBu2”), Takahashi reagent (“Cp2ZrEt2”), and Rosenthal reagent (Cp2Zr(py)TMSC≡CTMS). The well-known system of reagents Ti(OPr)4 - i-PrMgBr should also be mentioned. Recently, we have shown the promise of using a reagent based on tantalum (TaCl5 – Mg) for the reduction of propargylamines. Continuing these studies, in order to develop new catalytic systems for the homo-coupling of acetylenic compounds, in this work we studied the TaCl5-catalyzed reaction of dialkyl-substituted acetylenes with EtAlCl2 and Mg.
We have established for the first time that the reaction of dialkyl-substituted acetylenes with EtAlCl2 and magnesium in the presence of catalytic amounts of tantalum (V) chloride in a toluene solution after hydrolysis and deuterolysis gives tetraalkyl-substituted (E,E)-buta-1,3-dienes in high yield. A selective method for the preparation of tetraalkyl-substituted (Z,Z)-1,4-dichlorobuta-1,3-dienes based on the reaction of aluminacyclopentadienes formed in situ with methanesulfonyl chloride has been developed. A plausible scheme for the catalytic conversion has been proposed.

  • Open access
  • 12 Reads
Preparation and characterization of 5-sulfosalicylic acid grafted to a chitosan-based support for the synthesis of quinazoline derivatives under green chemistry conditions
, , ,

In this research, the three-component synthesis of quinazoline derivatives with various substitutions has been investigated using a new chitosan-based catalyst grafted by 5-sulfosalicylic acid under green chemistry conditions. FT-IR, NMR, XRD, EDX, VSM, and FESEM spectroscopic, microscopic or analytical methods were used for characterization of the new catalyst as well as identification of quinazoline derivatives. The obtained results show significant catalytic activity of the supramolecular nanocatalyst for the expeditious and efficient synthesis of 2,3-dihydroquinazoline-4(1H)-one derivatives, as an important pharmaceutical scaffold, via a three-component one-pot condensation of isotonic anhydride and aromatic aldehydes with amine sources.