Comparative study on the role of extracts of male and female of jojoba’s leaves in the green synthesis of α-MnO2 as an antimicrobial agent

Abstract The green synthesis method is a predominant trend as it is an ecofriendly, cleaner, scalable, and cheaper method and viable to form biocompatible NPsrather than the traditional methods. Jojoba plant is a natural and strong antioxidant as it contains phenolic and flavonoids compounds.Since male and female jojoba plants are known to differ in enzymatic and non-enzymatic antioxidant activity and phytochemical composition, this comparison was designed to test whether such sex-linked phytochemical variability translates into measurable differences in the structural, morphological, and antimicrobial properties of the resulting MnO 2 nanoparticles. This study focuses on preparation of MnO 2 nanoparticles using the extract of male (M-MnO 2 ) and female (F-MnO 2 ) jojoba ’ s leavesand to evaluate theirantimicrobialactivity.The prepared samples were characterized using X-ray diffraction (XRD), energy dispersive X-ray (EDX) and Thermal analyses (TGA & DTG) to assess their structural and physicochemical properties. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) also used to assess the morphology and microstructure evolution. The X-ray diffraction analysis confirmed the cryptomelane-type α-MnO 2 phase for both samples distinguished by its characteristic (2 × 2) tunnel framework capable of hosting potassium ions within the crystal lattice. The microstructure analyses also reveal the nanocrystalline nature with flake morphology of MnO 2 NPs that enhances the surface reactivity helping in improving the antimicrobial performance.The antimicrobial efficacy of the two samples (M-MnO 2 and F-MnO 2 ) was evaluated throughtheCup Diffusion Agar Method and the Colony Forming Unit (CFU) Assay using Four representative microorganisms were selected for testing: Staphylococcus aureus ATCC 6538-P (Gram-positive bacterium), Escherichia coli ATCC 25,933 (Gram-negative bacterium), Candida albicans ATCC 10,231 (yeast), and Aspergillusniger NRRL-A326 (filamentous fungus).The findings of this research highlight sample F-MnO 2 as a potential antimicrobial agent with higher percent of the inhibition zones and higher reduction percent of the number of colonies formation.