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Efficient Synthesis and Reactions of New Piperidinyl Tetrahydropyrimido[4′,5′:4,5]thieno[2,3-c]isoquinolines and Related Heterocycles

Research Abstract

Acetylation of 1-amino-5-(piperidin-1-yl)-N-phenyl-6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxamide (3) with acetic anhydride afforded unexpected [1,3]oxazinothienoisoquinolinone derivative in an excellent yield instead of the expected N-phenylpyrimidothienoisoquinolinone. Diazotization of 3 using sodium nitrite in acetic acid and sulfuric acid yielded the corresponding triazinothienoisoquinoline, while the reaction with triethyl orthoformate in acetic acid produced N-phenylpyrimidine derivative 7. Chloroacetylation of compound 3 with chloroacetyl chloride in dioxane at 60–70°C yielded chloroacetamido compound 8, which underwent ring closure upon reflux in acetic anhydride to produce the chloromethyl oxazinone derivative 9. Oxazinone derivatives 5 and 9 underwent nucleophilic substitution upon treatment with ammonium acetate/acetic acid mixture and hydrazine hydrate to afford pyrimidinone …

Research Authors
Remon M Zaki, Adel M Kamal El-Dean, Shaban M Radwan, Asmaa SA Sayed
Research Date
Research Department
Research Journal
Russian Journal of Organic Chemistry
Research Year
2025

Preparation, insecticidal activity estimation, DFT calculations, and molecular docking of some polyfunctionalized pyridine derivatives

Research Abstract

This study investigated the insecticidal bioefficacy of seven compounds (1-7) against maize aphid (Rhopalosiphum maidis). Results indicated that LC50 values ranged from 1.52 to 18.45 mg/L for nymphs and 23.96 to 80.73 mg/L for adults. Compound (6) demonstrated the highest potency, with LC50 values of 1.52 mg/L against nymphs and 23.96 mg/L against adults, establishing it as the most effective analogue for potential aphid control. The other compounds also exhibited varying degrees of insecticidal activity. For nymphs, compound (5) was notably effective, followed by compound (7), and compound (3) with LC50 values of 2.23, 2.37, and 2.45 mg/L, respectively, indicating their promising potential. Compounds (4), (2), and (1) showed comparatively lower efficacy against nymphs with LC50 values of 12.19, 14.14, and 18.45 mg/L, respectively. Similarly, for adults of maize aphids, compounds (5), (7), and (3 …

Research Authors
Eman Ali Thabet, Abdullah Abdalkarim Al–Shara, Abdel Haleem M Hussein, Ahmed AK Mohammed, Adel M Kamal El-Dean, Mokhtar A Abdul-Malik, Ali M Drar, Fathia Mohammad Qasem Qaid, Shaban AA Abdel-Raheem
Research Date
Research Department
Research Journal
Journal of the Indian Chemical Society
Research Year
2025

Synthesis, Antimicrobial Activity, Molecular Docking and Molecular Dynamics Studies of Novel Bioactive Compounds Derived from Propylthiouracil

Research Authors
Mostafa Ahmed, Mahmoud M Hamed, Mostafa Sayed, Ahmed A El-Rashedy, Adel M Kamal El-Dean, Mohammad HA Hassan, Mohamed F Mady, Mahmoud S Tolba
Research Date
Research Department
Research Journal
JOURNAL OF MOLECULAR STRUCTURE
Research Year
2025

Multifunctional polyamides: Designing rigid and flexible architectures for flame retardant, dye adsorbent, single-material white-light emitting, and color-tunable …

Research Abstract

Two novel polyamides, Poly(Oxa) and Poly(Pip), were successfully synthesized through the polycondensation of 1,4-bis(2-chloroacetamido)benzene with either 5,5′-(1,4-phenylene)bis(1,3,4-oxadiazole-2-thiol) or piperazine, respectively. Comprehensive computational, structural, morphological, thermal, and photophysical analyses revealed distinct structure–property relationships governed by the nature of the polymer backbone. Poly(Oxa), containing a heteroaromatic framework, exhibited pronounced conjugation and semi-crystallinity, confirmed by FT-IR and XRD analyses. This architecture imparted exceptional thermal stability (char yield: 42.4 %), high flame retardancy (LOI = 34.5 %), and a heterogeneous morphology with strong π–π stacking interactions, which enhanced methylene blue adsorption. Remarkably, Poly(Oxa) displayed excitation-dependent photoluminescence, shifting from deep-blue to …

Research Authors
Osama Younis, Aya Harby, Esam A Orabi, Adel M Kamal El-Dean, Marwa M Sayed, Mahmoud S Tolba
Research Date
Research Department
Research Journal
Reactive and Functional Polymers
Research Year
2025

New AIEgens based on thieno [2, 3-d] pyrimidine derivatives: Synthesis, DFT calculations, and molecular docking

Research Abstract

In this paper, new thieno[2,3-d]pyrimidine analogs have been synthesized and characterized through different spectroscopic techniques. The photophysical properties of the molecules (7b-7f) and the quantum chemical calculations have been investigated. These molecules exhibited aggregation-induced emission behavior and showed efficient emission in both solid and solution states. A shift toward shorter wavelengths (hypsochromic shift) was observed when transitioning from the solution to the solid state, which could be explained by photoinduced intramolecular charge transfer (ICT) processes. DFT calculations confirmed that the diverse behavior of the thieno[2,3-d]pyrimidine analogs could be attributed to variations in molecular packing and rigidity. This study illustrates how luminophores aggregation can occur without significantly impacting the excited state, emphasizing the unconventional behavior …

Research Authors
Amira Zaki Ebrahim, Ahmed AK Mohammed, Mostafa Ahmed, Adel M Kamal El-Dean, Mahmoud S Tolba
Research Date
Research Department
Research Journal
Journal of Photochemistry and Photobiology A: Chemistry
Research Year
2025

Synthesis, in silico and in vivo evaluation of new pyrazole-based thiosemicarbazones containing thiazole and thiazolone moieties as potential anti-inflammatory agents

Research Abstract

This study presents the efficient synthesis of a novel series of pyrazole-thiosemicarbazone derivatives (3-7) from a key precursor (2) via cyclization with α-halocarbonyl compounds. The structures of all synthesized hybrids were unequivocally confirmed through elemental analysis and comprehensive spectral studies (IR, NMR, MS). Among them, in vivo anti-inflammatory evaluation in a carrageenan-induced paw edema model identified compounds 3 and 4 as exceptionally potent, exhibiting significant inhibition rates of 66.67% and 73.08%, respectively. Molecular docking studies revealed strong and favorable binding interactions of these lead compounds with the active sites of cyclooxygenase enzymes (COX-1 and COX-2), providing a rational structural basis for their observed efficacy. Furthermore, in silico pharmacokinetic predictions indicated that 3 and 4 possess promising drug-likeness and oral bioavailability …

Research Authors
Mokhtar A Abdul-Malik, Adel M Kamal El-Dean, Abdel Haleem M Hussein, Aboubakr H Abdelmonsef, Mahmoud S Tolba
Research Date
Research Department
Research Journal
Journal of Molecular Structure
Research Year
2025

New class of Thienopyridines: Design, synthesis, antimicrobial activity and molecular docking study

Research Abstract

Thienopyridines one of the most important classes in organic chemistry due to their outstanding medicinal and environmental applications. In this study, we report the synthesis of a series of novel thienopyridine derivatives bearing different aryl substituents on the fused thiophene moiety to showcase their inhibition behavior on different strains of bacteria and Fungai which can further be evidenced by molecular docking. The 4,6-dimethyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile (3) was used as a starting material for the synthesis of the target compounds (4-15). The condensation of compound 3 with thiophene-2-carbaldehyde led to formation of thienylpyridine product 4, which subsequently reacted with ethyl chloroacetate or chloroacetaldehyde to furnish the thienopyridine derivatives (6,7). Moreover, the alkylation of compound 3 with various bromoalkyl ketones followed by Thorpe-Zeigler cyclization furnished the …

Research Authors
Azhaar T Alsaggaf, Mostafa Sayed, Ahmed Dewan, Ahmed A El-Rashedy, Adel M Kamal El-Dean, Mostafa Ahmed
Research Date
Research Department
Research Journal
Journal of Molecular Structure
Research Year
2025

First microscopic and molecular identification of Cryptosporidium spp. in fat sand rats (Psammomys obesus) in Egypt and their potential zoonotic implications

Research Abstract

Introduction: Rodents, thriving in human-altered environments, pose significant
public health risks due to their role as reservoirs for numerous zoonotic parasites.
Among these, Cryptosporidium spp. are recognized globally as leading causes
of waterborne and foodborne diarrheal illnesses in humans. The specific role of
fat sand rats (Psammomys obesus) in the transmission of Cryptosporidium spp.
in Egypt and the genotypic characteristics of the circulating species in these
animals remain poorly understood.
Methods: In this study, a total of 150 individual fat sand rat stool samples were
collected from the saline marsh periurban areas of Abu-Rawash, Giza, Egypt. The
samples were initially screened for the presence of Cryptosporidium spp. using
light and scanning electron microscopy to characterize the parasite’s oocysts.
Furthermore, molecular identification and characterization of the parasite
were carried out on selected microscopy-positive samples (n = 30) using
conventional polymerase chain reaction (PCR) targeting the Cryptosporidium
oocyst wall protein (COWP) gene. A subset of these positive samples by PCR was
subjected to sequencing, with the resulting sequences deposited in GenBank™
and analyzed through phylogenetic methods.
Results: Conventional microscopy revealed that 46.7% (70/150; 95% CI:
38.7–54.6) of the analyzed stool samples contained structures consistent
with Cryptosporidium oocysts. Moreover, the molecular analysis confirmed
Cryptosporidium species in DNA from all 30 stool samples previously identified
as heavily infected through microscopy. Notably, the phylogenetic analysis
identified Cryptosporidium parvum (C. parvum) in the sequenced samples, likely
originating from the rats’ native habitats. These identified species have been
deposited in GenBank™ under the accession numbers OM817461 (C. parvum FSA-1), OM817462 (C. parvum FSA-2), and OM817463 (C. parvum FSA-3) and revealed closed genetic identity with those species reported from human and other animal species in the same geographic location.
Conclusion: Overall, this study represents the first morphological and genetic identification of C. parvum isolated from fecal samples of fat sand rats trapped from periurban areas in Egypt. These findings provide valuable insights into the potential zoonotic implications of rodents in disease transmission at the national level, offering crucial information for public health awareness campaigns and informing local authorities.

Research Authors
Sara Abdel-Aal Mohamed , Fatma A. S. Anwar , Ahmed Gareh , Marwa M. I. Ghallab , Remigio Martínez , Asmaa Aboelabbas Gouda , Fatemah Enad Alajmi , Hind Alzaylaee , Ignacio García-Bocanegra and Ehab Kotb Elmahallawy
Research Date
Research Department
Research Journal
frontiers in veterinary science
Research Pages
8
Research Publisher
Frontiers Media SA
Research Rank
Q1
Research Vol
11
Research Website
https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2024.1488508/full
Research Year
2025

The combined effects of sulfamethoxazole and ammonia in manure-based biomethanation process: reactor performances, microbial responses, and metabolic mechanisms

Research Abstract

Anaerobic digestion (AD) is a sustainable and feasible technology to treat livestock manure. However, the effects of coexisting ammonia and antibiotics on the AD process of livestock manure are still unclear. A potential ammonia-antibiotics synergistic co-inhibition might occur. Therefore, the individual and combined effects of different ammonia (1000–7000 mg NH4+-N/L) and sulfamethoxazole (SMX) concentrations (0.1–20 mg SMX/L) on the biomethanation process were explored. The results indicated that a significant reduction (43.83%) in methane production was observed under individual 5000 mg NH4+-N/L (A5000 +SMX0.1), while a 20.11% increase was achieved by individual 0.5 mg SMX/L (A1000 +SMX0.5). Under the combined 5000 mg NH4+-N/L and 0.5 mg SMX/L (A5000 +SMX0.5), ammonia inhibition was alleviated with methane production increasing by 58.46% compared with A5000 +SMX0.1 (still 25.89% lower than A1000 +SMX0.5). However, combined high SMX concentrations (≥ 5 mg/L) and ammonia levels (≥ 5000 mg NH4+-N/L) might exacerbate the inhibition of the AD process. Moreover, microbial analyses revealed that A1000 +SMX0.5 improved the acetoclastic methanogenic pathway by enriching key acetoclastic methanogens (Methanothrix), syntrophic bacteria (Syntrophomonas) and hydrolytic-acidogenic bacteria (norank_f__Bacteroidetes_vadinHA17) under high ammonia stress. Conversely, under 5 mg SMX/L the abundances of these functional microorganisms decreased. Metagenomic results further suggested that 0.5 mg SMX/L was associated with increased abundances of critical metabolic genes (glk, ak, acs, and mtr ), which were responsible for improving hydrolysis-acidogenesis, acetogenesis and acetoclastic methanogenesis and contributed to alleviation of ammonia inhibition. Overall, these batch-scale results could benefit future evaluation and optimization of continuous-flow anaerobic digesters treating substrates coexisting with ammonia and antibiotics.

Research Authors
Mingyao Zhou , Shuaishuai Man , Fei Shen , Mohamed Hemida Abd-Alla , Han Wang , Qun Yan
Research Journal
Journal of Environmental Chemical Engineering
Research Member
Research Pages
122842
Research Publisher
Springer Nature
Research Rank
Q1
Research Vol
Volume 14, Issue 3, June 2026, 122842
Research Website
https://doi.org/10.1016/j.jece.2026.122842
Research Year
2026
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