This work focused on removing iron with oxalic acid from red clay samples collected from Kapasia Upazila, Gazipur District, Bangladesh. To characterize the red clay, the study employed several techniques: particle size analysis, WDXRF (wavelength-dispersive X-ray fluorescence), AAS (atomic absorption spectroscopy), XRD (X-ray diffraction), TGA (thermogravimetric analysis), and FESEM (field emission scanning electron microscopy). Additionally, leaching experiments were conducted with varying concentrations of oxalic acid, temperatures and times. After leaching, the red clay composition changed significantly: SiO₂ increased from 53.6 % to 63.13 %, Fe₂O₃ decreased from 17.1 % to 3.64 %, Al₂O₃ remained relatively stable at 18 %–18.22 %, and other oxides showed minor variations. 78.71 % of the iron was removed at optimal leaching conditions (1.0 M oxalic acid, 100 °C, 150 min, and 250 rpm). Mineralogically, the red clay samples are composed of illite, kaolinite, quartz, feldspar, hematite and chlorite. Thermal analysis showed significant weight loss at temperatures between 300 and 600 °C. Ceramic trials were conducted at firing temperatures of 900 °C and 1100 °C to evaluate the mechanical properties of tiles. The results obtained showed significant improvements in red clay quality for ceramics. Being a low-cost and eco-friendly process, this becomes a very prominent alternative to conventional iron removal techniques and helps produce high-quality ceramic tiles, contributing towards economic growth in Bangladesh.

Trewia polycarpa, a member of the Euphorbiaceae family, is widely found in South and Southeast Asia, particularly in India, Sri Lanka, Malaysia, Indonesia, and the suburbs areas of Dhaka, Bangladesh. The present study investigated the n-hexane extraction of 137 mg (TPH-F-7), focusing on the isolation and structural characterization of β-sitosterol using chromatographic techniques, FTIR, ¹H-NMR, ¹³C-NMR, and DEPT-135 analyses. The FTIR spectrum revealed absorption peaks at 3444 cm⁻¹ (O-H stretching), 2953 cm⁻¹, 2924 cm⁻¹, 2870.1 cm⁻¹ (aliphatic C-H stretching), 1640 cm⁻¹ (C=C), 1458 cm⁻¹ (CH₂ bending), 1377 cm⁻¹ (OH deformation), 1100 cm⁻¹ (cycloalkane), and 797 cm⁻¹. The ¹H-NMR spectrum confirmed the presence of functional groups such as hydroxyl (-OH), methyl (-CH₃), methylene (-CH₂), and methine (-CH) groups, with notable singlets at δ 0.71 and 1.03 ppm and an olefinic proton triplet at δ 5.37 ppm. The ¹³C-NMR analysis identified 29 carbon atoms, including a hydroxyl-bearing carbon (δ 71.8 ppm), double bonds (δ 140.8 and 121.7 ppm), and methyl carbons (δ 11.86 and 18.78 ppm), with a γ-gauche interaction influencing C18’s chemical shift. DEPT-135 analysis revealed six methyl, eleven methylene, nine methine, and three quaternary carbons. The isolated compound was identified as β-sitosterol based on its structural features, steroidal properties, and melting point (134–136 °C). Furthermore, the notable interaction profile of a compound isolated from T. polycarpa against specific targeted receptors in a molecular docking study significantly substantiated the advancement of potential therapeutics that could be utilized in the treatment of a broad spectrum of health complications, to illustrate, cancer, diabetes, pain, and diarrhea. This study confirms that Trewia polycarpa is a potential source of β-sitosterol, a compound that significantly contributes to the plant’s pharmacological properties, including its anti-inflammatory, antioxidant, and antimicrobial activities, as well as its potential benefits for bone health and regenerative medicine, highlighting its multifaceted therapeutic potential.

The mineralogical, geochemical, and statistical characteristics of recent fluvial deposits from the Brahmaputra–Jamuna River, Bangladesh, were examined to determine their provenance, transport dynamics, and depositional environment. Sediments were analyzed using X-ray diffraction (XRD), wavelength dispersive X-ray fluorescence (WD-XRF), field emission scanning electron microscopy (FE-SEM), and electron probe microanalysis (EPMA). Grain size analysis revealed a predominance of medium-to-fine sand (mean grain size 1.77–3.43 ϕ), with moderately well-sorted textures (sorting: 0.33–0.77 ϕ), mesokurtic to leptokurtic distributions, and skewness values ranging from −0.21 to +0.30. Mineralogical results show a high quartz content with minor feldspar, mica, zircon, rutile, and iron-bearing minerals. Geochemical data indicates high SiO₂ (63.39%–70.94%) and Al₂O₃ (12.25%–14.20%) concentrations and calculated chemical index of alteration (CIA) values ranging from 60.90 to 66.82. The microstructural study revealed angular to sub-angular grains with conchoidal fractures and stepped microcracks, indicating brittle deformation under high-energy conditions, which is consistent with short transport distances, limited sedimentary recycling, and a derivation from mechanically weathered source rocks. Multivariate analyses (PCA and K-means clustering) of grain size parameters reveal two distinct sedimentary regimes, namely Cluster 1 as finer-grained (2.36 ϕ), poorly sorted sediments, and Cluster 2 as coarser (2.98 ϕ), well-sorted deposits. Discriminant function values (Y₂: 78.82–119.12; Y₃: −6.01 to −2.56; V₁: 1.457–2.442; V₂: 1.409–2.323) highlight shallow water, fluvial/deltaic aspects, and turbidite depositional environments. These findings advance the understanding of sedimentary dynamics within large, braided river basins and support future investigations into the sustainable management of fluvial depositional environments.

Background: Mica is widely applied in cosmetics, construction, automotive, electronics, defense, and medical industries, particularly important in cosmetics as an ingredient in foundations, eyeshadows, lipsticks, and nail polishes for its pearlescent and shimmering effects. Aims: To evaluate the suitability of mica minerals from Bangladeshi river sands for cosmetic applications by investigating their chemical composition, heavy metal content, potential for skin irritation, and antimicrobial activity. Methods: The chemical composition, crystallographic structure, and heavy metal content of mica samples were analyzed using X‐ray fluorescence, X‐ray diffraction, and Atomic Absorption Spectroscopy. Non‐carcinogenic and carcinogenic risks were evaluated using USEPA models (ADD, HQ, HI, LADD, ILTCR). Sensory evaluation was performed by 10 trained panelists, while primary skin irritation was tested on albino rabbits. Antimicrobial activity against bacterial and fungal strains was assessed using agar well diffusion and broth microdilution assays. Results: Muscovite contained high Al ₂ O ₃ (30.46%) and SiO ₂ (49.29%), whereas biotite and phlogopite were enriched in Fe ₂ O ₃ (43%) and MgO, supporting shimmer, color, and UV‐protective properties. XRD confirmed high crystallinity and purity. Heavy metals were within safe dermal and inhalation exposure limits. Sensory evaluation showed a silky texture, strong adhesion, and a luminous finish. All samples were non‐irritant (PII = 0.00). Biotite and phlogopite exhibited moderate antibacterial activity against Staphylococcus aureus , Salmonella typhi , and Bacillus megaterium , but no antifungal effects. Conclusions: Muscovite, biotite, and phlogopite mica exhibit low heavy metal content, non‐irritant and non‐carcinogenic behavior, moderate antibacterial activity, and favorable sensory properties, highlighting their potential as safe, effective, and multifunctional ingredients for cosmetic applications.

Long chain aliphatic ketones have gained increasing attention due to their structural diversity and broad pharmacological significance. Trewia polycarpa, a medicinal plant widely used in traditional healthcare systems of Bangladesh, remains underexplored as a source of such bioactive constituents. The n hexane extract of T. polycarpa root bark was subjected to silica gel column chromatography, leading to the isolation of a saturated aliphatic ketone. Spectroscopic and spectrometric analyses, including FTIR, ¹H-NMR, ¹³C-NMR, DEPT 135, and LC-MS/MS, in comparison with literature data, enabled the characterization and identification of the compound as hentriacontan 16 one. To investigate its potential biological relevance, molecular docking using PyRx software was performed against selected therapeutic targets, including bacterial hydrolase FphH (PDB ID: 8FTP), penicillin binding protein (6G9S), interleukin 10 (2ILK), cytochrome c peroxidase (1AEM), NF κB inducing kinase (6WPP), and the δ opioid receptor (6PT2). The compound exhibited moderate binding affinities (−5.7 to −4.8 kcal/mol), primarily driven by hydrophobic interactions. These findings represent the first report of hentriacontan 16 one from T. polycarpa and provide a foundation for future experimental bioassays, toxicity evaluations, and mechanistic studies. Subsequent research should emphasize large scale isolation and comprehensive bioassays to further assess its therapeutic potential and possible synergistic effects with other phytochemicals.

Traditional medicinal plants are widely used for therapeutic, nutritional, and cosmetic applications, yet their safety and quality remain major concerns due to possible contamination and processing related degradation. This study evaluates the physicochemical properties, antioxidant activity, and heavy metal-associated health risks of nine medicinal plant species commonly used in Bangladesh-ILCR, Phyllanthus emblica, Withania somnifera (leaf and root), Terminalia arjuna, Justicia adhatoda, Ocimum sanctum Linn., Hibiscus rosa-sinensis, Psidium guajava Linn., and Azadirachta indica processed through heat pump and traditional sun drying methods. Moisture, protein, and total phenolic contents were determined alongside DPPH radical scavenging activity to assess bioactive compound preservation. Heavy metal concentrations (Pb, Cd, Cr, Mn, As, Ni, and Se) were quantified via Graphite Furnace Atomic Absorption Spectroscopy (GF-AAS), and non-carcinogenic (HQ, HI) and carcinogenic (ILCR) health risks were estimated following USEPA guidelines. Results revealed that heat pump drying significantly enhanced protein and phenolic retention while reducing residual moisture compared to sun drying. DPPH assays confirmed superior antioxidant activity (up to 88% scavenging at 200 µg/mL) in heat pump dried samples. Heavy metal concentrations in all samples were below permissible limits, with HQ, HI, and ILCR values indicating negligible non-carcinogenic and carcinogenic risks. Heat pump drying demonstrated enhanced preservation efficiency of nutritional and bioactive components while minimizing contamination risks. These findings provide strong scientific evidence supporting the adoption of controlled heat pump drying for safer, higher-quality, and more efficacious herbal product development in Bangladesh and beyond.