Asian Journal of Physical and Chemical Sciences

Comparative Study on the Effect of the Extraction Methods on Chemical Composition and Biological Activity of Essential Oil from Commiphora myrrha Resin, Mogadishu, Somalia

Abdullahi Yusuf Mohamed — 2026-09-19

This study compared hydrodistillation and steam distillation for the extraction of essential oil from Commiphora myrrha resin and evaluated differences in yield, chemical composition, antioxidant activity, and antimicrobial activity. Steam distillation produced a higher essential-oil yield (3.25%) than hydrodistillation (1.25%). Hydrodistillation produced a pale-yellow oil with a density of 0.8766 g/cm³, whereas steam distillation produced a golden-yellow oil with a density of 0.8791 g/cm³. GC-MS analysis identified 69 components in the steam-distilled oil and 76 components in the hydrodistilled oil. The principal constituents of the steam-distilled oil were alpha-pinene (24.54%), terpinen-4-ol (13.21%), beta-ocimene (11.80%), caryophyllene (4.50%), and humulene (4.11%). The hydrodistilled oil was characterised mainly by alpha-pinene (28.54%), 3-carene (16.24%), terpinen-4-ol (9.07%), sabinene (5.55%), and o-cymene (5.42%). In the DPPH assay, steam-distilled oil showed significantly greater radical-scavenging activity than hydrodistilled oil at all tested concentrations (p < 0.05). Total antioxidant capacity was also higher for steam-distilled oil (0.32 ± 0.019 mg ASAeq/mg dw) than for hydrodistilled oil (0.249 ± 0.003 mg ASAeq/mg dw). Antimicrobial responses varied according to microorganism and concentration; hydrodistilled oil produced larger inhibition zones in several bacterial comparisons and against Candida albicans at 25%, whereas some comparisons showed no significant difference. The findings demonstrate that the extraction method influenced oil yield, volatile composition, and the measured biological activities under the tested conditions.

Electrochemically Exfoliated Graphene/Iron Oxide and Graphene/Iron Oxide/Bismuth Oxybromide Composites for Methylene Blue Adsorption: Synthesis, Characterization, Kinetic, and Isotherm Studies

Bintou Coulibaly — 2026-09-22

Methylene blue (MB) is a cationic dye whose removal from contaminated aqueous media is important for wastewater treatment. This study evaluated graphene/iron oxide (EG/Fe₃O₄) and graphene/iron oxide/bismuth oxybromide (EG/Fe₂O₃/BiOBr) composites for MB adsorption. The binary composite was prepared by electrochemical exfoliation; BiOBr was synthesised hydrothermally, and the ternary composite was subsequently assembled through hydrothermal treatment. The materials were characterised by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. XRD indicated Fe₃O₄ as the dominant iron oxide phase in EG/Fe₃O₄ and the presence of Fe₂O₃ and BiOBr in the ternary composite. Batch adsorption experiments examined contact time, initial MB concentration, and adsorbent dose. Equilibrium was reached after approximately 60 min in the contact-time experiments. The pseudo-second-order model provided the better kinetic fit for both composites. Equilibrium data were best described by the Langmuir model for EG/Fe₃O₄ and by the Freundlich model for EG/Fe₂O₃/BiOBr. The maximum adsorption capacities were 21.41 mg g⁻¹ and 27.10 mg g⁻¹, respectively. Maximum removal efficiencies of 99.8% for EG/Fe₃O₄ and 99.6% for EG/Fe₂O₃/BiOBr were obtained in the adsorbent-dose experiments. These findings indicate that both composites are effective MB adsorbents under the tested batch conditions, with differences in removal efficiency and adsorption capacity.

Antischistosomal Activity of Calotropis procera Flower Ethanol Extract

A. H. Mara — 2026-10-10

Schistosomiasis remains a major neglected tropical disease across sub-Saharan Africa, and control efforts rely almost entirely on a single drug, praziquantel, which has limited activity against juvenile schistosomes and no paediatric formulation. Medicinal plants therefore continue to be screened as potential sources of alternative or complementary antischistosomal agents. This study evaluated the phytochemical profile, chemical composition and antischistosomal potential of the flower of Calotropis procera, a plant widely used in African and Asian traditional medicine. Shade-dried, pulverised C. procera flowers were macerated in absolute ethanol and the crude extract was subjected to qualitative phytochemical screening, Gas Chromatography–Mass Spectrometry (GC–MS), Fourier Transform Infrared (FT–IR) and Ultraviolet–Visible (UV–Vis) spectroscopic analyses. Acute toxicity (LD₅₀) and histopathological assessment were carried out in albino rats, and antischistosomal activity was evaluated in vitro (schistosome suspension exposed to graded extract concentrations) and in vivo (Schistosoma-infected albino mice dosed orally at 50–600 mg/kg/day, referenced against praziquantel). The extract (22% yield) tested positive for alkaloids, phenols, tannins, flavonoids and flavonol glycosides. GC–MS resolved 24 constituents, dominated by the fatty-acid methyl ester 9,12-octadecadienoic acid (Z,Z)-, methyl ester (31.57% relative peak area), together with 3-chloro-5-((dimethylamino)methyl)-4,5-dimethyl-2(5H)-furanone (13.68%) and 9,15-octadecadienoic acid (Z,Z)-, methyl ester (11.85%). FT–IR spectra showed O–H, C–H and C–O absorptions consistent with the identified metabolite classes, and UV–Vis analysis showed a dominant absorption maximum at 279 nm indicative of conjugated chromophores. The extract was well tolerated up to 2000 mg/kg body weight (no mortality), with only mild peri-portal infiltration on liver histology. In vitro, the extract produced dose- and time-dependent immobilisation and death of schistosomes, with the highest effect (75–100% mortality) recorded within 15 minutes at concentrations ≥500 mg/kg. In vivo, oral extract administration reduced worm burden by 18–52% across the dose range tested, compared with 73% for praziquantel. Calotropis procera flower extract shows measurable, dose-dependent antischistosomal activity and a favourable acute-toxicity profile, supporting its potential as a source of lead antischistosomal compounds. Bioassay-guided isolation of the major constituents and mechanistic and sub-chronic toxicity studies are recommended before any therapeutic application is considered.

Chemical Characterisation of Cereals and Pulses in the Diets of Elite Chadian Combat Sports Athletes: A Focus on Proteins and Lipids for Precision in Dietary Recommendations

Allaissem Moyengar — 2026-10-13

Objective : This study aimed to characterise the dietary sources consumed by elite Chadian combat-sport athletes during the pre-competition period and to quantify the crude protein content and total lipid levels of the main cereals and pulses included in their diets.

Design : A descriptive investigation was conducted in N’Djamena between August 2023 and November 2024. Dietary data were collected in national accommodation and training centres hosting elite combat athletes during pre-competitive regrouping, while chemical analyses were performed at the Center for Food Quality Control (CECOQDA).

Materials and Methods : Dietary data were collected from 63 national-level athletes (31 women and 32 men), aged 16-29 years, using the Cubeau and Péquinot dietary assessment method adapted to local conditions. Crude protein content was determined using the Kjeldahl reference method, and total lipid content was measured using Soxhlet extraction.

Results : The athletes’ diet was predominantly plant-based, with plant sources representing 69% of total intake versus 31% from animal sources. Among pulses, white kidney beans (Phaseolus vulgaris) contained 13.74% protein and 1.35% lipids, while « Pois de terre » (Vigna subterranea) contained 11.40% protein and 5.82% lipids. Cereals showed lower protein values (4.21%-8.70%) and lipid contents ranging from 2.29% to 3.44%. The ANOVA revealed significant differences among food items (P < 0.05). Pulses exhibited substantially higher protein levels than cereals, confirming their role as the primary protein sources. Lipid content also differed significantly (P < 0.05), with « Pois de terre » showing the highest value (5.82 g/100 g), followed by millet and maize.

Conclusion : These findings provide essential baseline data for evidence-based nutritional recommendations in combat sports and contribute original insights into underexplored plant-based food resources in Chad. Further scientific investigations are required to achieve a comprehensive characterisation of the nutritional and phytochemical constituents of these cereals and pulses.

Dielectric Relaxation of Aqueous Glycine Investigated by Time-domain Reflectometry

Ravindra B. Talware — 2026-10-14

The dielectric response of aqueous glycine was examined from 10 MHz to 30 GHz at seven nominal temperatures between 25 and −5 °C over a reported composition series of 0–1.0 mol L⁻¹. Time-domain reflectometry data were interpreted with a single Cole–Davidson relaxation function to obtain static permittivity (ε₀), relaxation time (τ), high-frequency permittivity (ε∞), and the distribution parameter (β). At 25 °C, the reported ε₀ increased from 78.27 for water to 105.35 at the highest glycine concentration, while τ increased from 8.32 to 16.08 ps. Both parameters generally increased on cooling. An Eyring analysis performed by ordinary least-squares regression of the tabulated relaxation times yielded activation enthalpies ranging from approximately 8.53 to 10.89 kJ mol⁻¹ and concentration-dependent activation entropies. The reported Kirkwood correlation factor at 25 °C decreased from 2.82 for water to 1.57 at 8.9 wt% glycine, indicating a change in the effective orientational correlation under the adopted molecular model. The dielectric and thermodynamic trends are consistent with concentration- and temperature-dependent solute–solvent dynamics, although the fitted parameters alone do not uniquely establish a hydrogen-bonding mechanism or exclude multiple relaxation processes. Interpretation at subzero temperature is conditional on the uncharacterized sample phase.

Evaluation of Heavy Metal Contamination and Excess Lifetime Cancer Risk in Soil Samples Around Some Selected Dump Sites in South-South, Nigeria

Anyalebechi, Chinedu Denilson — 2026-10-15

Atomic absorption spectrophotometry (AAS) was used to determine the total concentrations of heavy metals (Pb, Ni, Zn, Fe, Cd, and Cr) in soil samples from Rumuolumini, Aluu, and Igwuruta communities in Rivers State, Nigeria. The study evaluated metal concentrations, contamination status, potential human-health risks, and Excess Lifetime Cancer Risk (ELCR) using mathematical models and regulatory guidance from the World Health Organization and the U.S. Environmental Protection Agency. A total of fifteen (15) soil samples were collected at a depth of 1 m below ground level and assessed using the Contamination Factor (CF), Pollution Load Index (PLI), Geo-accumulation Index (Igeo), Hazard Quotient (HQ), Hazard Index (HI), and ELCR. The results showed spatial variation in metal concentrations, with the overall heavy-metal burden following the order Aluu > Rumuolumini > Igwuruta. Most metals exhibited low contamination (CF < 1), whereas Cd showed considerable contamination at Aluu (3.79 ± 2.35) and Rumuolumini (3.23 ± 2.93). Mean PLI values were 0.248 ± 0.049, 0.156 ± 0.037, and 0.038 ± 0.013 for Aluu, Rumuolumini, and Igwuruta, respectively. The Igeo values similarly indicated generally unpolluted conditions, except for localised Cd enrichment. Mean HI values were 0.0299, 0.0204, and 0.0038, respectively, all substantially below unity. Mean total ELCR values were 2.87 × 10⁻⁵, 1.28 × 10⁻⁵, and 3.55 × 10⁻⁶, respectively, with Aluu recording the highest potential carcinogenic risk. Overall, the soils showed low general heavy-metal pollution and non-carcinogenic risk; however, localised Cd enrichment and the contributions of Ni and Cd to carcinogenic risk warrant continued environmental monitoring.

Evaluation of Radiological Hazard Indices in Selected Farmland Soils around Landfill Sites in Rivers State, Nigeria

Anyalebechi, Chinedu Denilson — 2026-10-17

Natural radionuclide levels and radiological hazard indices in soils from selected farmlands around landfills in Rivers State, Nigeria, were assessed using gamma-ray spectroscopy with a NaI (Ti) detector. The assessment considered ⁴⁰K, ²³⁸U and ²³²Th at the Aluu, IAUE and Igwuruta dumpsites. For Aluu, the calculated radium equivalent activity (Raeq) values in the present study ranged from 9.10 to 135.49 Bq/kg, with an average value of 62.24 ± 14.60 Bq/kg. The Iγ values ranged from 0.04 to 0.51, with a mean of 0.25 ± 0.06; Hₑₓ values ranged from 0.02 to 0.37, with a mean of 0.16 ± 0.04; and Hᵢₙ values ranged from 0.03 to 0.42, with an average of 0.22 ± 0.05. The absorbed dose rate ranged from 3.96 to 58.59 nGy/h, with a mean of 28.02 ± 6.31 nGy/h, while the AEDE values ranged from 0.00 to 0.07 mSv/y, with a mean of 0.03 ± 0.001 mSv/y. The gonadal dose ranged from 27.08 to 405.02 mSv/y. The ELCR values ranged from 0.08 × 10⁻³ to 1.12 × 10⁻³, with a mean of 0.48 ± 0.13 × 10⁻³, while the AUI values ranged from 0.08 to 1.12, with an average of 0.48 ± 0.13. For IAUE, the Raeq values ranged from 21.47 to 112.64 Bq/kg, with a mean of 85.60 Bq/kg. The Iγ values ranged from 0.09 to 0.49, with a mean of 0.37 ± 0.04; Hₑₓ values ranged from 0.06 to 0.30, with an average of 0.23 ± 0.03; and Hᵢₙ values ranged from 0.06 to 0.48, with a mean of 0.34 ± 0.04. The absorbed dose rate ranged from 11.13 to 50.39 nGy/h, with an average of 39.00 ± 4.18 nGy/h, while the AEDE values ranged from 0.01 to 0.06 mSv/y, with a mean of 0.05 ± 0.006 mSv/y. The gonadal dose ranged from 82.73 to 345.36 mSv/y, with a mean of 267.79 ± 27.82 mSv/y. The ELCR values ranged from 0.05 × 10⁻³ to 0.22 × 10⁻³, with a mean of 0.17 ± 0.02 × 10⁻³, while the AUI values ranged from 0.05 to 0.98, with an average of 0.70 ± 0.10. For Igwuruta, the calculated Raeq values ranged from 15.67 to 104.85 Bq/kg, with an average value of 54.13 ± 10.58 Bq/kg. The Iγ values ranged from 0.06 to 0.48, with a mean of 0.24 ± 0.05; Hₑₓ values ranged from 0.04 to 0.28, with an average of 0.15 ± 0.03; and Hᵢₙ values ranged from 0.04 to 0.47, with a mean value of 0.22 ± 0.05. The absorbed dose rate ranged from 7.17 to 47.90 nGy/h, with a mean of 25.23 ± 4.82 nGy/h, while the AEDE values ranged from 0.01 to 0.06 mSv/y, with a mean of 0.03 ± 0.006 mSv/y. The gonadal dose ranged from 51.14 to 326.57 mSv/y, with a mean of 175.00 ± 32.44 mSv/y. The ELCR values ranged from 0.10 × 10⁻³ to 0.21 × 10⁻³, with a mean of 0.11 ± 0.07 × 10⁻³, while the AUI values ranged from 0.10 to 0.89, with a mean of 0.40 ± 0.10. The radiological parameters varied among the three locations. IAUE recorded the highest mean values of Raeq (85.60 Bq/kg), Iγ (0.37), Hₑₓ (0.23), Hᵢₙ (0.34), absorbed dose rate (39.00 nGy/h), AEDE (0.05 mSv/y), gonadal dose (267.79 mSv/y) and AUI (0.70), indicating comparatively higher radiological activity. Igwuruta recorded the lowest values for most parameters, including Raeq (54.13 Bq/kg), absorbed dose rate (25.23 nGy/h), Hₑₓ (0.15) and AUI (0.40). In contrast, Aluu recorded the highest mean ELCR (0.48 × 10⁻³), compared with 0.17 × 10⁻³ at IAUE and 0.11 × 10⁻³ at Igwuruta, indicating a comparatively higher estimated lifetime cancer risk at Aluu. Overall, all three locations showed radiological indices generally below their respective recommended reference limits, suggesting a low overall radiological hazard, although Aluu warrants attention because of its relatively elevated ELCR. However, the Aluu site recorded the highest value of ELCR (0.48 × 10⁻³), suggesting a comparatively greater potential lifetime cancer risk. In summary, the findings indicate that the investigated soils do not pose a significant radiological threat under present conditions, although regular radiological monitoring and improved landfill management are recommended, especially at the Aluu dumpsite.