Abstract

In this study, oleuropein was isolated from olive leaves by chromatographic method and its structure was elucidated by spectroscopic analyses such as FTIR, ¹H-NMR and ¹³CNMR. Silver nanoparticles (AgNPs) were synthesized using oleuropein and their antioxidant activity was investigated using DPPH, ABTS^•+, and FRAP assays. The AgNPs were characterized by UV-Vis, FT-IR, XRD, and SEM analyses. The absorption peak at 450 nm in UV-Vis spectrum confirmed the AgNPs formation. Scanning electron microscope (SEM) identified the formation of spherical-shaped nanoparticles with the average size of 71 nm. Rietveld analysis was carried out by X-ray diffraction data with High Score Plus software. XRD with 2θ degrees at 38.1°, 44.3°, 64.4° and 77.4° can be assigned to the (111), (200), (220) and (311) Bragg’s reflections of the face-centered cubic crystalline structure. Biosynthetic nanoparticles revealed more inhibitory effect (5.22, IC_50, µg/mL) against ABTS^•+ than standard BHT (7.03, IC_50, µg/mL).

摘要

在这项研究中，通过色谱法从橄榄叶中分离出橄榄苦苷，并通过光谱分析如FTIR，¹ H-NMR和¹³ CNMR阐明了其结构。使用橄榄苦苷合成了银纳米颗粒（AgNPs），并使用DPPH，ABTS ^•+和FRAP分析研究了其抗氧化活性。通过UV-Vis，FT-IR，XRD和SEM分析来表征AgNP。UV-Vis光谱中450 nm处的吸收峰证实了AgNPs的形成。扫描电子显微镜（SEM）确定了平均大小为71 nm的球形纳米颗粒的形成。Rietveld分析是使用High Score Plus软件通过X射线衍射数据进行的。用XRD 2θ可以将面心立方晶体结构的（111），（200），（220）和（311）布拉格反射指定为38.1°，44.3°，64.4°和77.4°。生物合成的纳米颗粒对ABTS ^•+的抑制作用（5.22，IC _50， µg / mL）比标准BHT（7.03，IC _50， µg / mL）更好。