14 International Journal of Materials and Biomaterials Applications 2014; 4(1): 14-18 ISSN 2249–9679 Original Article Adenium obesum flower Extractaction and Application to synthesis of Silver Nanoparticles and Antioxidant R.M.Kershi 1* , Naji Ebrahim 2 1. Physics Department, Faculty of science, Ibb University, Ibb, Yemen. 2. Department of Plant Production, Faculty of Agriculture and Veterinary Science, Ibb University, Ibb,Yemen. *Email:-rkershi1@gmail.com Received 19 February 2014; accepted 26 February 2014 Abstract In this study environmentally friendly biosynthesis of sliver nanoparticles (AgNPs) using leaves extract of Adenium obesum have been achieved. AgNPs can be prepared with lower amounts of leaf extract in short time. Stable AgNPs were formed by treating solution using the plant leaf extracts as reducing agents. Biosynthesized nanoparticles were characterized by UV–V spectrophotometer. Also, this study aims to investigate and compare Adenium obesum L. extracts obtained in Ultrasonic condition with different water/methanol and water/ethanol extraction mixture acidified with 0.1% HCl. The extracts were analyzed for monomeric anthocyanins contents and antioxidant activities. The highest anthocy- anins content (18340.9 mg/L) and the best free radical scavenging activity were obtained for the Adenium obesum extract with 100% methanol. Also, there is a good correlations between antioxidant activity (R2 = 0.9368) for water/ethanol series extracts. © 2013 Universal Research Publications. All rights reserved Keywords: Adenium obesum , anthocyanins, antioxidant activity, sliver nanoparticles. Introduction Nanotechnology has a wide variety of applications in various fields like optics, electronics, catalysis, bio- medicine, magnetics, mechanics, energy science, etc. Nanobiotechnology is a multidisciplinary field involving research and development of technology in different fields of science like biotechnology, nanotechnology, physics, chemistry, and materials science [1-2]. Metal nanoparticles are usually in sizes smaller than 100 nm and possess unique physical and chemical properties. Especially, silver nanoparticles have been attributed to their small size, more surface bulk atoms and high surface area permits them to highly interact with microbial membranes. Besides, silver is used in the medical field and water purification. Many physical or chemical methods that are currently available for silver nanoparticle production but many of them have several disadvantages such as high cost, hazard. Recently, biosynthesis of silver nanoparticles has received a special attention due to environmentally friendly green synthesis and easy to scale-up. In recent years, several plant extracts have been successfully used and reported for fast and efficient extracellular synthesis of metal nanoparticles such as silver, copper and gold nanoparticles by using broth extracts of neem [3], Aloe vera [4], tamarind [5], Avena sativa [6], wheat [7], alfalfa [8], geranium [9], lemongrass [10] and tamarind [11]. Anthocyanins are representative of plant pigments widely distribut-ed in colored fruits and flowers. Because anthocyanins are widely consumed, finding out additional biological activities related to these compounds would be of great interest [12]. Anthocyanins are normally obtained by extraction from plants and the extraction methods currently employed are with the use metha-nol, ethanol, acetone, water or mixtures as solvents. In fact, the color stability of anthocyanins depends on a combination of factors, such as the structure and concentration of the anthocyanin, pH, temperature and presence of complex agents such as phenols and metals [13]. The most common solvents used for anthocyanins extraction are aqueous mixtures of ethanol, methanol or acetone [14]. The adverse effects of oxidative stress on human health have become a serious issue [15]. Under stress, our bodies produce more reactive oxygen spe-cies (ROS) such as; superoxide anion radicals, hydroxyl radicals and hydrogen peroxide than enzymatic antioxidants such as; superox-ide dismutase [16], glutathione peroxidase, and catalase and non-enzymatic antioxidants such as; ascorbic acids, glutathi-one, carotenoids, and flavonoids. This imbalance leads to damage of biological structures such as proteins, lipids and DNA and induce a variety of human diseases [17- 22]. Antioxidants from fruits and vegetables, Available online at http://www.urpjournals.com International Journal of Materials and Biomaterials Applications Universal Research Publications. All rights reserved