The green synthesis of silver nanoparticles (AgNPs) using herbal plants has gained much attention due to their potential widespread applications, especially in biomedical application to control pathogenic microbes. The aim of our study was to evaluate the antibacterial properties of synthesized AgNPs using aqueous leaf extract of Piper betle L., an important medicinal plant. The AgNPs were identified by UV-Visible spectrometry (UV-Vis), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectrometry (FT-IR). The presence of surface plasmon band around 420-460 nm indicated AgNPs formation. Spherical nature, unique size-distribution and crystal structure of the AgNPs with diameter around 10-20 nm were affirmed by TEM and XRD analyses. The FTIR measurements showed the presence of bioactive compounds in the extract responsible for the efficient reduction of silver ions and stabilization of the AgNPs. The results from the antimicrobial assays suggested that the biosynthesized AgNPs were potent against pathogenic bacteria including Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.
Shengming Zhao,Liu Yang,Mengran Hei,Yanan Zhao,Mingming Zhu,Hui Wang,Haixu Zhou,Hanjun Ma
The effects of pepper leaf polyphenols (PLPs) on the conformation and functional characteristics of porcine myofibrillar proteins (MPs) under oxidative conditions were investigated. The addition of PLPs remarkably retarded the increase of carbonyl content and the average particle size of MPs after oxidation. Moreover, the sulfhydryl content, solubility, and the storage modulus (G′) of oxidized MPs were improved with the increased addition of PLPs to 1 g/100 mL. PLPs contributed to an increment in surface hydrophobicity when the incorporation of PLPs was 0.5 g/100 mL. The intrinsic fluorescence strength and FT-IR results indicated that PLPs altered protein conformation by exposure of the hydrophobic group and the conversion of α-helices to β-turn structures. Scanning electron microscopy results suggested that PLPs contributed to the orderly and uniform appearance of MPs. Furthermore, molecular docking analysis elucidated that arginine, glutamic acid, aspartic acid and glutamine were the predominant binding sites between MPs and the phenolic compounds of PLPs. Consequently, PLPs could be employed as a potential natural antioxidant to alleviate oxidation and modify the functional characteristics of meat products.
Leather is often used to make comfortable shoes due to its soft and breathable nature. However, its innate ability to retain moisture, oxygen and nutrients renders it a suitable medium for the adsorption, growth, and survival of potentially pathogenic microorganisms. Consequently, the intimate contact between the foot skin and the leather lining surface in shoes, which are subject to prolonged periods of sweating, may result in the transmission of pathogenic microorganisms and cause discomfort for the wearer. To address such issues, we modified pig leather with silver nanoparticles (AgPBL) that were bio-synthesized fromPiper betleL. leaf extract as an antimicrobial agent via the padding method. The evidence of AgPBL embedded into the leather matrix, leather surface morphology and element profile of AgPBL-modified leather samples (pLeAg) was investigated using colorimetry, SEM, EDX, AAS and FTIR analyses. The colorimetric data confirmed that the pLeAg samples changed to a more brown color with higher wet pickup and AgPBL concentration, owing to the higher quantity of AgPBL uptake onto the leather surfaces. The antibacterial and antifungal activities of the pLeAg samples were both qualitatively and quantitatively evaluated using AATCC TM90, AATCC TM30 and ISO 16187:2013 test methods, approving a good synergistic antimicrobial efficiency of the modified leather againstEscherichia coliandStaphylococcus aureusbacteria, a yeastCandida albicansand a moldAspergillus niger. Additionally, the antimicrobial treatments of pig leather did not negatively impact its physico-mechanical properties, including tear strength, abrasion resistance, flex resistance, water vapour permeability and absorption, water absorption and desorption. These findings affirmed that the AgPBL-modified leather met all the requirements of upper lining according to the standard ISO 20882:2007 for making hygienic shoes.Keywords:silver nanoparticles;green synthesis;Piper betleL. leaf;pig lining leather;antibacterial activity;antifungal activity
危险品化学品经营许可证（带存储）