Curcuma zedoaria (Christm.) Roscoe (Zingiberaceae), commonly called white turmeric or zedoary, is a chemically complex rhizomatous species used in Asian traditional medicines and increasingly investigated as a source of volatile and non-volatile bioactive constituents. This critical narrative review evaluates the chemical composition, biological activities and acute-toxicity evidence for essential oils, solvent extracts, fractions and isolated compounds of C. zedoaria. Literature published from 1968 to 6 August 2026 was examined through accessible scholarly databases and citation searching, with emphasis on studies in which botanical identity, preparation, chemical characterisation and experimental design could be appraised. The evidence shows pronounced compositional heterogeneity. Rhizome oils have been reported as curzerenone-, epicurzerenone-, zerumbone-, camphor-, 1,8-cineole-, beta-curcumene- or mixed sesquiterpene-rich, while leaf oil and non-volatile fractions show distinct profiles. Geographic provenance, accession, plant organ, processing, extraction and analytical procedures therefore limit the validity of treating “zedoary oil” as a single reproducible intervention. Preclinical studies support antimicrobial, antiparasitic, insecticidal, anti-inflammatory, analgesic, antiproliferative, antiangiogenic, hepatoprotective, antimutagenic and wound-related activities, and several isolated sesquiterpenes and diarylheptanoids have plausible molecular targets. Nevertheless, most efficacy evidence derives from in vitro assays or small animal models, often without cross-study chemical standardisation, pharmacokinetic information, exposure matching or independent replication. Safety evidence is substantially thinner than efficacy evidence. Preparation-specific acute and subchronic findings range from tolerability at selected doses to marked toxicity of inadequately processed rhizome material, an intraperitoneal essential-oil median lethal dose in mice, haematological and reproductive effects after repeated extract exposure, and developmental toxicity of essential oil in pregnant rats. These data do not support a single species-wide safe dose. Future work should prioritise voucher-confirmed material, chemotype-defined preparations, validated quantitative chemistry, exposure-based toxicology, reproductive-safety assessment and human studies designed around standardised products. Overall, C. zedoaria is pharmacologically promising but translational confidence remains constrained by chemical variability and an underdeveloped safety evidence base.
The utilisation of agricultural residues as reinforcement in polymer composites offers an approach for developing value-added materials from renewable resources. This study evaluated alkali-treated cassava tuber fibre as a reinforcing filler in urea-formaldehyde (UF) resin composites. The prepared fibres were treated with 2.5% w/v sodium hydroxide and incorporated into UF-based formulations at different fibre and urea loadings. Composite specimens were evaluated for tensile strength, Vickers hardness and impact strength. Tensile testing indicated a maximum stress of 2.077 MPa for the 8 g urea formulation compared with 0.527 MPa for the virgin UF control; however, these tensile measurements were obtained from single specimens and were therefore interpreted descriptively. In the fibre-loading series, Vickers hardness increased to a maximum of 16.70 HV at 0.8 g fibre before decreasing at 1.0 g fibre. In the urea-loading series, the highest hardness was 16.30 HV at 12 g urea. Impact energy reached its highest value of 0.80 J at 0.2 g fibre, while the 12 g urea formulation recorded 0.60 J. Impact measurements showed appreciable variation among some replicate specimens. Overall, the results indicate that changes in fibre loading and urea content affected the measured mechanical responses of the UF composites. Further experiments with greater replication and controlled formulation combinations are required to confirm the observed trends and establish reproducible optimum processing conditions.
The rapid increase in plastic waste generation poses serious environmental, social, and economic challenges, particularly in developing countries such as Nigeria, where disposal infrastructure is inadequate. This study investigates the design and formulation of hot mix asphalt incorporating waste polyethylene terephthalate (PET) and high-density polyethylene (HDPE) for road and pavement construction. Using the dry mix method, PET and HDPE were processed to 2–4 mm and blended with 70/80 penetration grade bitumen and aggregates at 2%, 3%, 4%, 5%, and 6% by weight of the mix. Thirty Marshall specimens were prepared and evaluated for stability, flow, voids, voids filled with bitumen (VFB), and density in accordance with ASTM D1559. Results revealed that asphalt mixes containing PET and HDPE exhibited improved stiffness and resistance to rutting relative to the control. Optimal performance was observed at 2–4% plastic content. PET mixes showed higher Marshall Stability at 6% (4.70 kN) and higher VFB (81.42%) compared with HDPE. The incorporation of plastic waste offers significant environmental benefits by diverting waste from landfills and reducing binder demand, while also offering potential cost savings and extended pavement lifespan. The study concludes that integrating PET and HDPE into asphalt pavement is a viable, sustainable approach, but recommends standardisation, durability testing, and field-scale validation.
This study presents a stepwise pedagogical framework designed to simplify the learning and application of IUPAC nomenclature for aliphatic organic compounds. Undergraduate learners often find nomenclature challenging because several interdependent rules must be considered simultaneously during the construction of a chemical name. The proposed framework organises the naming process into five sequential components—secondary prefix (2°-P), primary prefix (1°-P), word root, primary suffix (1°-S), and secondary suffix (2°-S)—to provide learners with a consistent and structured sequence for applying established nomenclature principles. Importantly, the proposed format is intended as an instructional framework and does not replace or modify IUPAC nomenclature rules. Its pedagogical usefulness was evaluated through a quasi-experimental study involving 64 undergraduate chemistry students. Students were divided into two groups: one was taught using a conventional instructional approach, while the other was taught using the proposed stepwise framework. Both groups completed identical pre-test and post-test assessments and nomenclature exercises. Students taught using the stepwise framework showed greater improvement in test performance and greater efficiency in completing naming exercises than those taught using the conventional approach. Feedback from students and faculty further indicated that the framework was easy to understand, recall, and apply, and helped reduce confusion during name construction. The findings suggest that the proposed stepwise framework may serve as a useful pedagogical tool for facilitating the teaching and learning of IUPAC nomenclature in undergraduate chemistry education.
Piper nigrum L. and Piper cubeba L. are aromatic pepper species recognised for their phytochemical diversity. This study compared the phenolic composition of six pepper accessions collected in Côte d’Ivoire, including two P. nigrum cultivars, Lompung (LG) and Muntok (MK), and four P. cubeba accessions, AC1, AC2, AB, and BH. Dried berry powders were extracted using 80% methanol, and the contents of total polyphenols, total flavonoids, anthocyanins, flavonoid aglycones, hydrolyzable tannins, and condensed tannins were determined using spectrophotometric methods. The results showed significant variation among species and accessions. Total polyphenol contents ranged from 35.656 to 89.082 µg GAE/g of extract, with the highest value recorded in MK. Total flavonoid contents ranged from 26.588 to 62.946 µg/g of extract, with the highest value observed in the AB accession. Flavonoid aglycones were most abundant in LG, with 0.411 mg/g of extract, while anthocyanin contents were highest in LG and BH. Hydrolyzable tannins and condensed tannins also varied among accessions, with comparatively high values observed in several P. cubeba accessions and in MK. These findings indicate that phenolic composition differs according to species and accession, suggesting that both P. nigrum and P. cubeba accessions may represent useful sources of phenolic compounds.
