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Diplorhynchus condylocarpon (Müll.Arg.) Pichon (Apocynaceae) leaves, stem bark, and roots are commonly used as popular folk medicine in Zambia and other African countries. This work aimed to find out the broad categories of phytocompounds present in the plant, screen the polyphenols, and assess the total polyphenolic content and the antioxidant activity of methanolic extracts of leaf, stem bark, and roots. Maceration was used to extract secondary metabolites for preliminary phytochemical screening. QuEChERS (quick, easy, cheap, effective, rugged, and safe), based technique was used to recover polyphenols for liquid chromatography with tandem mass spectrometry (LC-MS/MS) screening. Standard chemical tests were used for preliminary phytochemical screening. Total phenolic content (TPC) was evaluated using the Folin-Ciocalteu (FC) method at 765 nm. Total flavonoid content (TFC) was evaluated by the aluminum chloride colorimetric assay at 510 nm. Antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method at 517 nm. The preliminary phytochemical screening revealed the presence of antioxidants, polyphenols, and other valuable phytocompounds such as alkaloids, saponins, and terpenoids. The LCMS/MS polyphenolic screening revealed the presence of mainly polyphenolic metabolites. TPC values were higher in the leaf (171.099±0.515 mg GAE/g) and root (88.8093±3.156 mg GAE/g) than in the stem bark (71.061±0.515 mg GAE/g) extracts. Further, the leaf extract contained 129.402±0.407, the root contained 64.672±0.813, and the stem bark had 37.643±0.704 mg QE/g total flavonoids. The leaf extract exhibited in a dose-dependent manner higher DPPH radical scavenging activities (34.250, 50.625, 66.562, 81.406, and 97.344%), followed by the root (16.406, 31.406, 50.781, 65.625, and 82.188%), and the stem bark extract only had the least DPP quenching activities (15.469, 27.969, 40.469, 52.500, and 68.590%) for the concentration of 20, 40, 60, 80 and 100 µg/mL respectively. Further, the results from the DPPH assay show that the leaf extract had the best IC50 value of 19.973 µg/mL, followed by the root extract with 60.867 µg/mL, and the stem bark extract with 107.150 µg/mL. These antioxidant activities support the traditionally claimed therapeutic benefits of D. condylocarpon leaves, stem bark, and roots in the treatment of oxidative stress-related disorders such as diabetes mellitus, chronic wounds, and diarrhea. This study may lead to the production of new herbal medicines using D. condylocarpon.

For centuries, phytochemicals have been of immense value to communities worldwide. These metabolites have been used in healthcare systems as medicines to treat various diseases. Further, phytochemicals are used as lead compounds in the synthesis of drugs. The extraction of compounds from plant materials is the cornerstone of natural product research. There has been a relentless endeavor to discover better extractive methods. In the same vein, several promising modern green extraction methods such as supercritical fluid, ultrasound, accelerated solvent, microwave, enzyme-assisted extraction methods are gaining significance. This review describes and discusses the various extraction techniques used to obtain the phytochemicals from different plant parts. These extraction techniques include the conventional solvent-based and the more robust modern and green extraction techniques. The review critically analyses the extraction conditions, optimized situations, advantages, and disadvantages of these extraction techniques. The review includes the recent applications of these extraction techniques. The review will propel advanced research and applications in the extraction process, a significant and integral component of natural products research.

Abstract: The increasing population has subjected rivers and streams to high levels of both industrial and domestic pollution. Significant environmental challenges have been brought about by their effects, particularly with regard to biota, ecosystem processes, soil quality, and groundwater pollution. This study examined the effects of human activity by applying pollution index models to evaluate the input of toxic elements in river sediments. Prior to sediment quality analysis, the total amount of arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg), thorium (Th), and uranium (U) was determined in the concentration range of 1.09–10.0 mg/kg, 8.53–475 mg/kg, 0.12–0.16 mg/kg, 4.85–77.5 mg/kg, 3.14–5.9 mg/kg and 0.93–2.86 mg/kg, respectively. The enrichment factor, contamination factor, pollution load index, and geo-accumulation index revealed alarmingly high levels of Pb and Hg contamination at some sampling points, which are related to possible human input, ranging from severe enrichment to considerable contamination. The low ranges of pollution indices of some toxic elements suggest enrichment through the natural weathering process and atmospheric deposition. The Pearson correlation coefficient revealed a significant correlation between Pb-Fe and As-Fe, suggesting the possibility of acid mine contamination. Continual monitoring of river sediment is essential to minimize the impact of toxic elements to sustain sediment health and quality. [ABSTRACT FROM AUTHOR]

Nickel hydroxide (Ni(OH)2) is a valuable compound derived from nickel, widely utilized across various fields because of its versatile properties. This study aimed to characterize as-prepared β-Ni(OH)2 via chemical precipitation using various analytical techniques. X-ray diffraction (XRD) analysis confirmed the formation of a β-Ni(OH)2 hexagonal crystalline structure, validating the successful precipitation. Fourier-transform infrared spectroscopy (FTIR) spectra exhibited main characteristic peaks of (υOH) and υ(NiO), corresponding to the formation of nickel hydroxide (Ni(OH)2). Subsequently, X-ray photoelectron spectroscopy (XPS) revealed a prominent peak for Ni2+ oxidation, confirming the successful precipitation of nickel hydroxide at pH 6.5, which identifies the existence of impurities, such as chlorine and calcium, from the waste matrix. Scanning electron microscopy (SEM) micrographs demonstrated stratified granules with a nearly pure brucite crystalline phase, typical of β-Ni(OH)2. Furthermore, the surface morphology revealed a coarse texture and uneven clustering, suggesting possible elevated oxide levels on the Ni surface. Energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of nickel (Ni) and oxygen (O), with Ca impurities attributed to the chemical precipitation process. Particle size distribution analysis estimated an average particle size of 2.0 µm. Additionally, the precipitation of nickel was investigated using inductively coupled plasma optical emission spectroscopy (ICP-OES). Ni was observed in decreasing order, 62.7 g/L, 0.8 g/L, and 0.501 g/L in the pregnant leach, precursor solution, and solid precipitate (cake), respectively. The separation of Ni(OH)2 through the precipitation process from the waste (acidic chloride media) enabled efficient recycling and re-use of nickel, which provides a cost-effective and environmentally friendly method for the highly efficient utilization of waste (acidic chloride media). [ABSTRACT FROM AUTHOR]

The research focused on risk assessment of some heavy metals in common vegetables and fish sold on open markets in three towns of Zambia. The mean level of heavy metals ranged as follows (mg/kg): 1.9 to 662.7, 3.0 to 3472.3 and 2.0 to 1698.7 of cadmium (lowest) and aluminium (highest) for samples from Kabwe, Kitwe and Lusaka, respectively. Statistical analysis indicated that the concentrations of samples from Kitwe and Lusaka towns were similar, P > 0.05. However, there were noteworthy differences in the mean amounts of heavy metals in samples from Kitwe and Kabwe, and samples from Kabwe and Lusaka towns, P <.0167. The health risk analysis indicates possible non-carcinogenic and carcinogenic risks to the consumer. This is because the hazard index (HI) for all metals in all samples from all towns was greater than 1 and the cancer risk (CR) for cadmium was above 10−4 in all samples from all towns. [ABSTRACT FROM AUTHOR]