Chemistry and Biochemistry: Research Progress Vol. 10

Eco-friendly Solid-state Synthesis and Optical Characterisation of Polyaniline Nanoparticles

Diaa Atta, Neveen M. Farrage, Amr M. Abdelghany — Mon, 13 Apr 2026 00:00:00 +0000

Polyaniline is one of the most important conductive materials with various applications ranging from electronics to biomedical engineering. The versatility of PANI originates from its complex molecular structure, which consists of phenylene rings linked by chemically flexible nitrogen-containing groups. Recent advancements have shifted focus toward the fabrication of PANI-based nanostructures and inorganic and polymer nanocomposites. The study aims to demonstrate a green method for producing Polyaniline (PANI) nanoparticles. This chapter presents an easy, straightforward method for preparing and characterising PANI nanoparticles. PANI nano-particles were prepared using the solid-state polymerisation method in the presence of different amounts of ammonium peroxydisulfate (APS) for the synthesis of PANI nano-particles. Different characterisation methods have been introduced as simple, easy-to-use characterisation techniques, along with the assignment of each spectroscopic test. Vibrational structure and electronic transitions were studied using FTIR and UV-Vis spectroscopic techniques. PANI nano-particles were formed in emeraldine salt form. The optical band gap (Eg) of PANI nanoparticles, calculated from UV-Vis spectra using the Tauc relation, was 4.45 eV and exhibited a size-dependent shift, decreasing with increasing particle size and increasing with decreasing size. This behaviour could be attributed to quantum confinement. The effect of concentration on the crystallinity index was studied using X-ray diffraction (XRD).

In silico Screening of Tridax procumbens Bioactive Compounds as Potential SARS-CoV-2 Inhibitors

Prajakta A. Dhage, Archana A. Sharbidre — Mon, 13 Apr 2026 00:00:00 +0000

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the urgent need for the discovery of novel antiviral agents capable of targeting multiple stages of the viral life cycle. Medicinal plants represent a valuable source of structurally diverse bioactive compounds with demonstrated antiviral potential. In the current chapter, selected phytoconstituents from Tridax procumbens were computationally screened against key SARS-CoV-2 targets, with a primary focus on the main protease (Mpro/3CLpro) and proteins involved in viral entry. A total of 22 selected phytochemicals, including flavonoids, glycosides, and other bioactive plant metabolites, were screened computationally to capture both the quantitative range and chemical diversity of T. procumbens constituents. Molecular docking analysis demonstrated that several phytoconstituents from T. procumbens exhibit favourable binding affinities and stable interactions with functionally important residues of viral proteins. Among the screened compounds, Luteolin, Bergenin, Puerarin, and Centaurin demonstrated some of the strongest binding interactions with key catalytic and functional residues of SARS-CoV-2 target proteins. Interaction analysis suggested that hydrogen bonding, hydrophobic interactions, and aromatic stacking play critical roles in stabilising ligand–protein complexes, indicating potential interference with viral replication and host cell entry. Furthermore, in silico pharmacokinetic and ADMET profiling of the lead compounds showed acceptable drug-likeness and preliminary safety profiles, supporting their potential for further development as an anti-SARS-CoV-2 therapeutic candidate.

Network-Based In-silico Analysis Suggests Potential Links Between 4‑Nonylphenol Exposure and Medulloblastoma-Related Signalling

Pratibha Gaurav, Avantika Pal, Gautam Geeta Jiwatram — Mon, 13 Apr 2026 00:00:00 +0000

Introduction: Endocrine-disrupting chemicals (EDCs), particularly 4-Nonylphenol (4-NP), pose significant neurodevelopmental risks. However, their mechanistic involvement in medulloblastoma (MB), a common pediatric brain tumour, remains largely unexplored.

Objectives: This study aimed to elucidate the molecular mechanisms through which 4-NP exposure may contribute to MB pathogenesis, with a specific focus on cerebellar granule cell precursors (GCPs), using an integrative bioinformatics approach.

Methods: Potential gene targets of 4-NP and MB-associated genes were retrieved from the Swiss Target Prediction and Gene Cards databases, respectively. A total of 35 overlapping genes were identified and subjected to protein–protein interaction (PPI) network construction using STRING and Cytoscape. Pathway and gene ontology enrichment analyses were conducted using Enrichr, while transcription factors (TFs) and miRNA interactions were analysed using TRRUST v2 and MIENTURNET, respectively.

Results: Potential 4-NP targets (SwissTargetPrediction; algorithm thresholds 0.65 for 2D and 0.85 for 3D) and MB-associated genes were intersected to identify 35 overlapping genes, which were analysed using STRING (confidence score ≥0.7) for network and enrichment analyses. PPI analysis revealed NFKB1, PTGS2, and ESR2 as central hubs, indicating dysregulation in Notch2, PI3K-Akt, and NF-κB signaling pathways. Further regulatory analysis highlighted TP53 and RELA as major TFs and hsa-miR-150-5p and hsa-miR-146a-5p as key miRNAs targeting hub genes. These findings suggest a multi-hit disruption mechanism involving Notch2-mediated proliferation, inflammatory PI3K-Akt/NF-κB signalling, and epigenetic reprogramming via miRNAs.

Conclusion: This in silico network-based study provides the first comprehensive evidence linking 4-NP exposure to MB molecular pathways. It identifies PTGS2 as a potential biomarker and suggests Notch2/PI3K inhibition as a therapeutic strategy. The study underscores the urgent need to reassess 4-NP safety limits in consumer products and offers new insights at the interface of environmental toxicology and pediatric neuro-oncology.

Computational Insights into the Diabetogenic Potential of 4-Nonylphenol Via Estrogen and Insulin Signaling Interference

Sandhya Sharma, Shubhanshi Kulshrestha, Gautam Geeta J. — Mon, 13 Apr 2026 00:00:00 +0000

Background: Endocrine disrupting chemicals (EDCs) are present in daily use products such as detergents, personal care products and plastics. These EDCs are associated with different metabolic and endocrine disorders. 4-Nonylphenol is a byproduct produced after the breakdown of alkylphenol ethoxylates. 4-NP shows estrogenic action and persists in the environment for a long time. There is possibility of interference in glucose homeostasis and involvement in developing Type Diabetes Mellitus (T2DM) by interfering with the signalling pathways related to estrogen and insulin.

Objective: In the present study molecular interaction between 4-NP and target proteins related to estrogen and insulin signaling to understand its possible role in metabolic disorders such as T2DM.

Methods: The present study used an in-silico molecular docking bioinformatic tool to predict the molecular interaction between 4-NP and nine target proteins related to estrogen and insulin signalling pathways. Nine target proteins were selected: ESR1, ESR2, GPER, INSR, IRS1, IRS2, PI3K, AKT, and GLUT-4 and binding affinities were determined by using AlphaFold, AutoDock Vina, and Maestro. Furthermore, AlphaFold and LigPlot were used to determine hydrogen bonds and hydrophobic interactions.

Results: The docking analysis showed that the binding affinity of the ligand ranged from -6.2 to -9.1 kcal/mol. The strongest binding has been observed for PI3K and GLUT-4, indicating that the ligand might interfere with insulin-induced glucose uptake. The presence of stable complexes was confirmed by the presence of 1-3 hydrogen bonds and hydrophobic interactions. The binding of the ligand to ESR1, ESR2, and GPER (binding affinity of around -7.5 to -8.0 kcal/mol) also indicated that the ligand might modulate the function of estrogen receptors and the role of β cells in the pancreas.

Conclusions: The study suggests that the ligand 4-NP might strongly interact with target proteins that play important roles in the regulation of estrogen and insulin signalling.

PSA Levels in BPH, BPH+UTI and Prostate Cancer: Diagnostic Implications

Priya Duvedi, Shilpa Rattan, Kanika Dhiman, Abid Manzoor — Mon, 13 Apr 2026 00:00:00 +0000

Background: Prostate-specific antigen (PSA) is a widely used screening biomarker for prostate diseases. Although organ‑specific, it lacks disease specificity; elevated serum PSA levels are observed not only in prostate cancer (PCa) but also in benign prostatic hyperplasia (BPH), prostatitis, urinary tract infection (UTI), and after prostatic interventions. This diagnostic overlap often leads to unnecessary biopsies and patient anxiety, underscoring the need for comparative evaluation of PSA across these conditions.

Aim: The study aims to evaluate and compare serum PSA levels in patients with BPH, BPH complicated by UTI, and prostatic carcinoma.

Methods: This hospital‑based cross‑sectional study included 300 male patients aged >50 years presenting with lower urinary tract symptoms. Participants were categorised into four groups: BPH (n=162), prostatic carcinoma (n=50), BPH+UTI (n=63), and healthy controls (n=25). Serum PSA was estimated by sandwich ELISA. Data were analysed using ANOVA and Pearson’s correlation.

Results: BPH was the most common diagnosis (54%). In the BPH and prostatic carcinoma groups, PSA levels showed no significant age‑related variation (p=0.445 and p=0.129, respectively). However, a significant association between age and PSA was observed in the BPH+UTI group (p=0.050), with the highest mean PSA (13.81 ng/mL) in patients aged >90 years. No significant correlation was found between International Prostate Symptom Score (IPSS) and PSA in BPH patients (p=0.129).

Conclusion: PSA elevation reflects underlying prostate pathology rather than age alone, with infectious and inflammatory conditions contributing substantially to increased levels. The lack of disease specificity necessitates cautious interpretation of PSA results alongside clinical findings, digital rectal examination, and histopathological evaluation to avoid misdiagnosis and overtreatment.

Effects of Incineration Ash Landfill Soil on PHB Biodegradation

Young-Cheol Chang — Mon, 13 Apr 2026 00:00:00 +0000

Background: Poly(3-hydroxybutyrate) (PHB) microbial degradation proceeds primarily through degradative enzymes secreted by bacteria and fungi, but there are differences in degradation mechanisms due to the specificity of the secreted enzymes. In bacterial PHB degradation, extracellular PHB depolymerases are secreted that specifically hydrolyse the ester bonds on the PHB surface, generating low-molecular-weight compounds such as 3-hydroxybutyric acid.

Aim: The study aims to investigate the effects of incineration ash-containing landfill soil on PHB biodegradation and to isolate and identify PHB-degrading bacteria under highly alkaline conditions.

Study Design: Comparative experimental study using incineration ash-containing landfill soil and university campus soil as control.

Place and Duration of Study: Nishi-Iburi Regional Union Final Disposal Site and Muroran Institute of Technology campus, Muroran, Hokkaido, Japan, 2024–2025.

Methodology: PHB films (0.02 g) were buried in landfill and university soils at 30°C for up to 63 days. Soil pH, bacterial and fungal CFU, and bacterial community structure were assessed. Degradation experiments were also conducted with Ralstonia sp. C1 inoculation. PHB-degrading bacteria were isolated on 0.1% PHB agar medium and identified via 16S rRNA gene sequencing.

Results: Landfill soil showed a strongly alkaline pH of 9.7 ± 0.05, with bacterial CFU approximately 40-fold lower [(2.1 ± 0.33) × 10⁶ vs. (4.4 ± 0.17) × 10⁸ CFU/g] and fungal CFU approximately 300-fold lower than university soil. PHB degradation reached only 65.2% in landfill soil vs. 100% in university soil by day 63. Even with Ralstonia sp. C1 inoculation, degradation remained suppressed (35.4% vs. 79.8% at day 28). Only 8 PHB-degrading strains were isolated from landfill soil vs. 16 from university soil, and all landfill isolates were Gram-positive (Actinomadura, Kitasatospora, Priestia), whereas university soil yielded both Gram-positive (Streptomyces) and Gram-negative (Ralstonia) strains.

Conclusion: Highly alkaline conditions in incineration ash-containing landfill soils markedly suppress PHB biodegradation by adversely affecting microbial community structure and viable cell counts. These findings underscore the importance of disposal-environment-specific material evaluation and the need for strategies to promote biodegradation under alkaline landfill conditions.

Effects of Phthalate Ester and Glycol-Based Plastic Additives on Polyhydroxybutyrate (PHB) Biodegradation by Ralstonia sp. C1

Young-Cheol Chang — Mon, 13 Apr 2026 00:00:00 +0000

Background: Phthalate esters are representative plasticisers. Understanding how plastic additives are involved in the biodegradation behaviour of polyhydroxybutyrate (PHB) is an indispensable issue for considering future biodegradable material design and additive selection.

Aim: The study aims to evaluate the effects of phthalate ester plasticisers and glycol-based additives on PHB biodegradation by Ralstonia sp. strain C1.

Study Design: A controlled laboratory experiment was conducted using liquid minimal salt medium (MSM) with PHB as the sole carbon source and individual additives at defined concentrations.

Place and Duration of Study: Muroran Institute of Technology, Muroran, Hokkaido, Japan, 2024–2025.

Methodology: Ralstonia sp. strain C1, isolated from Kurodake in Daisetsuzan National Park, Hokkaido, was cultivated in PHB-supplemented MSM. Phthalate esters (DEHP, DAP, DBP, BBP, DIBP, MBP, DEP) were tested at 200, 500, and 1000 µg/L; glycol-based additives (PEG, DPDM, DBG, TEG) at 2500 mg/L. Residual PHB was quantified every 24 hours over 96 hours by HPLC following acid depolymerisation to 3-hydroxybutyric acid. All experiments were conducted in triplicate.

Results: No significant inhibition of PHB degradation was observed for any phthalate ester additive at 200–500 µg/L. Among glycol-based additives at 2500 mg/L, DPDM and TEG showed minimal effect, whereas PEG exhibited transient inhibition at 24 and 48 hours. DBG showed strong inhibition at 48 hours. Further investigation is warranted to fully characterise the inhibitory effect of DBG.

Conclusion: Phthalate ester plasticisers do not substantially impede PHB biodegradation by Ralstonia sp. C1 at environmentally relevant concentrations. PEG may transiently suppress degradation at high concentrations, possibly through preferential microbial metabolism. These findings provide baseline data for designing PHB-based biodegradable products with environmentally compatible additives.