Biosynthesis of copper nanoparticles using Alstonia scholaris leaves and its antimicrobial studies.

The utilization of plants for the production of metallic nanoparticles is gaining significant attention in research. In this study, we conducted phytochemical screening of Alstonia scholaris (A. scholaris) leaves extracts using various solvents, including chloroform, ethyl acetate, n-hexane, methanol, and water. Our findings revealed higher proportions of flavonoids and alkaloids in both solvents compared to other phytochemical species. In the methanol, extract proteins, anthraquinone and reducing sugar were not detected. On the other hand, the aqueous extract demonstrated the presence of amino acids, reducing sugar, phenolic compounds, anthraquinone, and saponins. Notably, ethyl acetate and chloroform extracts displayed the highest levels of bioactive compounds among all solvents. Intrigued by these results, we proceeded to investigate the antibacterial properties of the leaf extracts against two major bacterial strains, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). All extracts exhibited significant zones of inhibition against both bacterial isolates, with S. aureus showing higher susceptibility compared to E. coli. Notably, the methanol extract displayed the most potent I hibitory effect against all organisms. Inspired by the bioactivity of the methanol extract, we employed it as a plant-based material for the green synthesis of copper nanoparticles (Cu-NPs). The synthesized Cu-NPs were characterized using Fourier infrared spectroscopy (FT-IR), UV-visible spectroscopic analysis, and scanning electron microscopy (SEM). The observed color changes confirmed the successful formation of Cu-NPs, while the FTIR analysis matched previously reported peaks, further verifying the synthesis. The SEM micrographs indicated the irregular shapes of the surface particles. From the result obtained by energy dispersive X-ray spectroscopic analysis, Cu has the highest relative abundance of 67.41 wt%. Confirming the purity of the Cu-NPs colloid. These findings contribute to the growing field of eco-friendly nanotechnology and emphasize the significance of plant-mediated approaches in nanomaterial synthesis and biomedical applications.

Antimicrobial activity, phytochemical screening of crude extracts, and essential oils constituents of two Pulicaria spp. growing in Sudan.

The search for plant extracts with highly antimicrobial activity has been increased nowadays. This study evaluated the antimicrobial activity of Pulicaria crispa (Forsk.) Oliv., and Pulicaria undulata (L.) C.A.Mey., which have been used traditionally in Sudan as insect replants. The antimicrobial activity was evaluated against six pathogenic microorganisms, four bacteria (two Gram-positive; Bacillus subtilis and Staphylococcus aureus, two Gram-negative; Escherichia coli, and Pseudomonas aeruginosa), and two fungi (Aspergillus niger and Candida albicans) using disc diffusion method. The extraction of the crude extracts was done by maceration. The essential oils were extracted by hydro-distillation. Phytochemical screening was done using reference method. Essential oils were analyzed using Gas Chromatography Mass Spectrometry. The results indicated that all used the microorganisms were sensitive to the plants extracts. Results of the preliminary phytochemical screening showed the presence of saponins, comarins, tannins, sterols, and triterpenes, and absence of alkaloids, anthraquinones, and flavonoids. Twenty-eight and forty-five constituents were identified in P. crispa and P. undulata, essential oils, respectively. The main constituents in the essential oil of P. crispa were 1,4-ditert butylbenzene (22.81%), caryophyllene (13.19%), carvone (11.80%), and neryl(s)-2-methylbutanoate (10.33%), and for P. undulata were camphor (44.48%), and thymyl acetate (10.31%). Data from this study could be used for developing of natural bioactive agents to improve human health.