Nuclear Versus Side-Chain Bromination of 4-Methoxy Toluene by an Electrochemical Method

Parallel Paired Photoelectrochemical Bromination of Alkylarenes with Electrochemical Pinacol Coupling

A paired electrochemical method for paralleling benzylic bromination of alkylarenes under irradiation with reductive pinacol coupling in a divided cell has been developed. A variety of benzyl bromides at the anode and pinacols at the cathode were obtained simultaneously in moderate-to-high faradaic efficiency. This parallel paired electrochemical protocol showed a broad substrate scope and high chemoselectivity as well as high synthetic and faradaic efficiencies.

Sulfonated magnetic spirulina nanobiomaterial as a novel and environmentally friendly catalyst for the synthesis of dihydroquinazolin-4(1H)-ones in aqueous medium

Spirulina algae is an excellent candidate for catalyst preparation due to its reactive functional groups, cost-effectiveness, widespread commercial accessibility, and biodegradability. In this study, magnetized Spirulina was used for the synthesis of dihydroquinazolin-4(1H)-ones (DHQZs) as catalyst. Magnetized Spirulina was produced by CoFe2O4 and sulfonation method using chlorosulfonic acid to create the catalyst [CoFe2O4-Sp-SO3H]. It was affirmed by various techniques, including Fourier transform infrared (FT-IR), Vibrating sample magnetometry (VSM), Powder X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), Field emission scanning electron microscopy (FE-SEM), and elemental mapping techniques. DHQZs synthesis was accomplished through a concise one-pot, three-component reaction involving a range of diverse aldehydes, isatoic anhydride, and primary aromatic amine, within an aqueous medium. The method offers several advantages, including using green conditions, the generation of several new 2-furan-quinazolinone derivatives, chromatography-free purification, short reaction times, appropriate yield of product (75-96%), and catalyst recyclability. The proposed catalyst and water as solvent demonstrated a strong synergistic effect, leading to the prosperous synthesis of various novel dihydroquinazolinones at 60 °C. These numerous benefits make our approach highly attractive for academic research and industrial applications.

Urea-rich porous organic polymer as a hydrogen bond catalyst for Knoevenagel condensation reaction and synthesis of 2,3-dihydroquinazolin-4(1H)-ones

In this research, a new urea-rich porous organic polymer (urea-rich POP) as a hydrogen bond catalyst was synthesized via a solvothermal method. The physiochemical properties of the synthesized urea-rich POP were investigated by using different analyses like Fourier transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), energy-dispersive X-ray spectroscopy (EDS), elemental mapping analysis, X-ray diffraction analysis (XRD) and Brunauer-Emmett-Teller (BET) techniques. The preparation of urea-rich POP provides an efficacious platform for designing unique hydrogen bond catalytic systems. Accordingly, urea-rich POP, due to the existence of several urea moieties as hydrogen bond sites, has excellent performance as a catalyst for the Knoevenagel condensation reaction and multi-component synthesis of 2,3-dihydroquinazolin-4(1H)-ones.

Insecticidal Effect of the Entomopathogenic Fungus Lecanicillium araneicola HK-1 in Aphis craccivora (Hemiptera: Aphididae)

Aphis craccivora (Hemiptera: Aphididae) is an important pest affecting various crops worldwide. However, only few studies have been conducted on the infection of A. craccivora by Lecanicillium and related insecticidal mechanisms. We investigated the infection process of A. craccivora by Lecanicillium araneicola HK-1 using fluorescence microscopy and scanning electron microscopy (SEM), and our results indicated that the conidia of strain HK-1 easily attached to the feet and dorsum of A. craccivora. The activities of chitinase and extracellular protease were induced in the aphid after treatment with HK-1. A bioassay on A. craccivora showed that the median lethal concentration (LC50) of the fungus crude extract was 24.00 mg mL-1 for 24 h of treatment. Additionally, the results showed that the crude extract disrupted the enzyme system of A. craccivora, inducing the inhibition of carboxylesterase (CarE) and the induction of glutathione S-transferase (GST) and acetylcholinesterase (AChE). Combining these results with those of a gas chromatography-mass spectrometry (GC-MS) analysis, it is suggested that p-cymene, hymecromone, 9,12-octadecadienoic acid (Z, Z) methyl ester, and 9,12-octadecadienoic acid (Z, Z) may be connected to the insecticidal effects we observed. This study provides a theoretical basis for the use of L. araneicola HK-1 as a potential biological control agent.

Magnetic cobalt oxide supported organosilica-sulfonic acid as a powerful nanocatalyst for the synthesis of tetrahydrobenzo[a]xanthen-11-ones

A novel core-shell structured magnetic cobalt oxide supported organosilica-sulfonic acid (Co3O4@SiO2/OS-SO3H) nanocomposite is prepared through a low-cost, simple, and clean method. The characterization of Co3O4@SiO2/OS-SO3H was performed by using Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD), energy dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM). The TGA and FT-IR results illustrate the high stability of the designed nanocomposite. The SEM image showed a size of about 40 nm for the Co3O4@SiO2/OS-SO3H nanoparticles. Furthermore, according to the result of VSM analysis, the saturation magnetization of this nanocomposite was about 25 emu/g. This novel material was used as an efficient nanocatalyst for the synthesis of biologically active tetrahydrobenzo[a]xanthen-11-one derivatives. These products were obtained in high to excellent yields under green conditions. The recoverability and reusability of this catalyst were also investigated under applied conditions.

Chicoric Acid: Natural Occurrence, Chemical Synthesis, Biosynthesis, and Their Bioactive Effects

Chicoric acid has been widely used in food, medicine, animal husbandry, and other commercial products because of its significant pharmacological activities. However, the shortage of chicoric acid limits its further development and utilization. Currently, Echinacea purpurea (L.) Moench serves as the primary natural resource of chicoric acid, while other sources of it are poorly known. Extracting chicoric acid from plants is the most common approach. Meanwhile, chicoric acid levels vary in different plants as well as in the same plant from different areas and different medicinal parts, and different extraction methods. We comprehensively reviewed the information regarding the sources of chicoric acid from plant extracts, its chemical synthesis, biosynthesis, and bioactive effects.

Cyclization of N-acetyl derivative: Novel synthesis – azoles and azines, antimicrobial activities, and computational studies

2-Pyridone is considered as one of the most famous efficient pharmaceutical compounds. Many approaches were discovered to synthesize 2-pyridone. In this present research, chloroacetylation of benzylamine at simple conditions, EtONa/EtCOONa produced N-benzyl-2-chloroacetamide 2. Compound 2 was allowed to react with different reagents. These reagents are acetylacetone, ethyl cyanoacetate, ethyl acetoacetate, and diethyl malonate, creating 2-pyridone derivatives with a good yield. The structures of the prepared compounds were elucidated by spectral data (IR, 1HNMR, and 13CNMR). The synthesized compound was tested for its antimicrobial activity against the Gram-positive (Staphylococcus aureus) and the Gram-negative (Escherichia coli) bacteria. In addition, the antifungal activities of the compounds were tested against two fungi (Candida albicans and Aspergillus flavus). Molecular docking studies were applied using the Autodock vina method. Theoretical methods prove all the experimental results by using molecular docking using Autodock vina and by ADEMT studies. The docking results represent that compound 20 had the best docking free energy, and it is the effective compound toward the selected bacterial and fungal proteins. ADME studies showed that the only compound 18 could cross the blood–brain barrier, and compound 15 was predicted to be soluble.

A Compilation of Synthetic Strategies to Access the Most Utilized Indoloquinoline Motifs

Indoloquinoline alkaloids constitute an important class of aromatic heterocycles consisting of quinoline and indole fused together in various orientations. These compounds, both natural and synthetic, often display various bioactivities which have established them to be one of the interesting medicinal targets. This class of compounds have stimulated much interest among synthetic and medicinal chemists as evidenced by growth in the number of synthetic methods to prepare and study this class of alkaloids. This review compiles the synthetic strategies and methods currently known in the literature for the construction of four important indoloquinoline skeletons.

Synthesis of triarylpyridines with sulfonate and sulfonamide moieties via a cooperative vinylogous anomeric-based oxidation

Herein, novel magnetic nanoparticles with pyridinium bridges namely Fe3O4@SiO2@PCLH-TFA through a multi-step pathway were designed and synthesized. The desired catalyst and its corresponding precursors were characterized with different techniques such as Fourier transform infrared (FT-IR) spectroscopy, 1H NMR, 13C NMR, Mass spectroscopy, energy dispersive X-ray (EDX) analysis, thermogravimetric/derivative thermogravimetry (TG/DTG) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). In addition, the catalytic application of the prepared catalyst in the synthesis of new series of triarylpyridines bearing sulfonate and sulfonamide moieties via a cooperative vinylogous anomeric-based oxidation was highlighted. The current trend revealed that the mentioned catalyst shows high recoverability in the reported synthesis.

K, Rayadurgam J, Rajasekhara Reddy S. Naturally derived sugar-based ionic liquids: an emerging tool for sustainable organic synthesis and chiral recognition

In the past decade, the synthesis of sugar-based ionic liquids (SILs) from natural sugars has been described as a promising strategy.

Total Synthesis of Novel Skeleton Flavan-Alkaloids

The first total synthesis of novel skeleton natural compounds kinkeloids A and B, a group of newly discovered flavan alkaloids isolated from the African plant Combretum micranthum, are described in this study. The key and final step are achieved by Mannich reaction, through which the piperidine moiety couples to the flavan moiety. The identities of synthesized kinkeloids were further confirmed through a comparison with the ones in the plant leaves extract using LC/MS.

Scalable Green Approach Toward Fragrant Acetates

The advantageous properties of ethylene glycol diacetate (EGDA) qualify it as a useful substitute for glycerol triacetate (GTA) for various green applications. We scrutinised the lipase-mediated acetylation of structurally diverse alcohols in neat EGDA furnishing the range of naturally occurring fragrant acetates. We found that such enzymatic system exhibits high reactivity and selectivity towards activated (homo) allylic and non-activated primary/secondary alcohols. This feature was utilised in the scalable multigram synthesis of fragrant (Z)-hex-3-en-1-yl acetate in 70% yield. In addition, the Lipozyme 435/EGDA system was also found to be applicable for the chemo-selective acetylation of (hydroxyalkyl) phenols as well as for the kinetic resolution of chiral secondary alcohols. Lastly, its discrimination power was demonstrated in competitive experiments of equimolar mixtures of two isomeric alcohols. This enabled the practical synthesis of 1-pentyl acetate isolated as a single product in 68% yield from the equimolar mixture of 1-pentanol and 3-pentanol.

Carvacrol activity & morphological changes in Mycobacterium tuberculosis

Aim: Evaluating carvacrol, derivatives and carvacrol plus anti-TB (anti-tuberculous) drug combination activities in Mycobacterium tuberculosis as well as carvacrol cytotoxicity, efflux pump inhibitor activity and morphological changes in M. tuberculosis H37Rv. Methods: Carvacrol (CAR) and derivatives’ activities were determined by resazurin microtiter assay and drug interaction by resazurin drug combination microtiter. Carvacrol cytotoxicity in VERO cells and efflux pumps inhibitor activity by ethidium bromide assay were determined and scanning electron microscopy performed. Results: Carvacrol MIC ranged from 19 to 156 μg/ml and carvacrol plus rifampicin combination showed synergistic effect in clinical isolates. No anti-M. tuberculosis activity improvement was observed with carvacrol derivatives. Carvacrol showed to be selective for M. tuberculosis, to have efflux pumps activity and to induce rough bacillary and agglomerates. Conclusion: Carvacrol shows good anti-M. tuberculosis activity and synergism with rifampicin.

Nanomagnetic zirconia-based sulfonic acid (Fe3O4@ZrO2-Pr-SO3H): a new, efficient and recyclable solid acid catalyst for the protection of alcohols via HMDS under solvent free conditions

In the present work, sulfonic acid functionalized nanomagnetic zirconia is prepared by the reaction of (3-mercaptopropyl)trimethoxysilane and nanomagnetic zirconia.