دانلود رایگان مقاله لاتین سنتز اوژنول استات از سایت الزویر
عنوان فارسی مقاله:
سنتز اوژنول استات توسط واکنش های آنزیمی در دی اکسید کربن فوق بحرانی
عنوان انگلیسی مقاله:
Synthesis of eugenyl acetate by enzymatic reactions in supercritical carbon dioxide
سال انتشار : 2016
برای دانلود رایگان مقاله سنتز اوژنول استات اینجا کلیک نمایید.
مقدمه انگلیسی مقاله:
1. Introduction
Low molecular weight esters represent an important class of aroma, consisting of compounds derived from short chain acids such as acetates, propionates and butyrates, which are often responsible for fruity aroma [1–3]. These esters, known for their flavoring properties, are present in essential oils of natural matter, which are technically difficult to extract, isolate and purify. Furthermore, conventional chemical synthesis leads to the formation of undesirable products to the food and pharmaceutical industries. Therefore, biocatalyzed chemical synthesis becomes of great interest due to the high chemo-, regio- and stereo-selectivity of the enzymes, which provide possible in vitro synthesis of naturally existing single enantiomers of specific compounds [2]. Moreover, the esters can be considered as natural [2–4], since the process meets the required conditions by the legislation. For example, the substrates or raw materials used in process are natural and only physical or biotechnological processes must be employed for the isolation and purification of the formed products [5]. Lipases (glycerol ester hydrolases, EC 3.1.1.3) belong to the hydrolase group and are responsible for catalyzing the hydrolysis of glycerol esters and long-chain fatty acids, producing alcohol and acid [6]. In many research works, lipases have been employed as catalysts for the synthesis of esters, such as isoamyl acetate (banana flavor) [3,7], isoamyl butyrate (pear flavor) [8,9] and cinamyl acetate (a compound of cinnamon essential oil) [10]. Besides, a recent research showed thatlipases are stable in pressurized fluids, which increased their potential use in esterification reactions [11]. Among the supercriticalfluids (SC) used inindustrial processes, carbon dioxide (CO2) is the most common due to its advantages, such as low cost, nontoxicity, non-flammability, inertness, full recovery and moderate critical properties (Pc = 7.38 MPa, Tc = 304.2K) when compared to other green solvents. Therefore, reactions in supercritical CO2 can be carried out with low energy cost for pressurization, and at temperatures that do not damage the enzymes [12,13]. Moreover, if SC-CO2 cannot improve reaction rate, the adjustable solvent power ofthe fluid allows the design of a production processwith integrated downstream separation of products and unreacted substrates [11]. Eugenyl acetate is an aroma ester generally found in the essential oil of clove buds (Syzygium aromaticum). Besides eugenyl acetate, clove oil is rich in eugenol, beta-carophyllene, alfahumulene and other minor compounds. The European Food Safety Authority (EFSA) evaluated and considered the application of eugenyl acetate safe as aromatic substance in food products. Actually, eugenyl acetate is listed on the database of the European Union as authorized substance to be used by the food industry [14]. Besides the flavoring property of eugenyl acetate, several works have reported other properties ofindustrialinterest, suchas antioxidant capacity [15], antimicrobial [16] and anticancer properties [17]. In this context, the aim of the present work was to investigate the synthesis of eugenyl acetate through enzymatic reactions in SC-CO2 media. The effects of enzyme and substrates’ concentration, temperature, pressure and number of reuse cycles of the enzymes were evaluated for two commercial immobilized lipases. The differences between two commercial immobilized lipases from C. antartica were shown. Moreover, experiments were performed to determine the kinetic parameters, and finally the phase behavior of the reaction system and the synthesis in organic medium were studied.
برای دانلود رایگان مقاله سنتز اوژنول استات اینجا کلیک نمایید.
کلمات کلیدی:
Eugenol Acetate 93-28-7 Route Of Synthesis _ Synthetic Routes www.molbase.com/en/synthesis_93-28-7-moldata-73966.html Eugenol Acetate 93-28-7 route of synthesis, Eugenol Acetate chemical synthesis methods, Eugenol Acetate synthetic routes ect. Crystal Structure Determination for Eugenyl Acetate | Gilberto Chierice ... www.academia.edu/21638810/Crystal_Structure_Determination_for_Eugenyl_Acetate No pro- Synthesis of Eugenyl Acetate cedure was introduced to grow the crystals. The decreased temperature during storage aided crystal nucleation and The ... EUGENOL ACETATE CAS#: 93-28-7 - Chemical Book www.chemicalbook.com › ... › Aliphatic dicarboxylic acid esters ChemicalBook provide Chemical industry users with EUGENOL ACETATE Boiling point Melting point,EUGENOL ... EUGENOL ACETATE Usage And Synthesis ... Eugenyl acetate Food and Flavor Ingredient, Flavis No 9.02 | Sigma ... www.sigmaaldrich.com/catalog/product/aldrich/w246905 Lipozyme TL IM as Catalyst for the Synthesis of Eugenyl Acetate in Solvent-Free Acetylation. María José A Silva et. al. Applied Biochemistry and Biotechnology, ... Toxicity of clove essential oil and its ester eugenyl acetate against ... www.scielo.br/pdf/bjb/2016nahead/1519-6984-bjb-1519-698412215.pdf by RL Cansian - 2016 - Cited by 1 - Related articles eugenyl acetate synthesis was 95.6%. The results about the evaluation of toxicity against the microcrustacean Artemia salina demonstrated that both oil (LC50= ... EUGENYL ACETATE - Chemicalland21.com www.chemicalland21.com/specialtychem/perchem/EUGENYL%20ACETATE.htm 1,3,4-Eugenol acetate; 1-Acetoxy-2-methoxy-4-allylbenzene; ... Chemically synthesized acetyl eugenol showed similar effects on AA- and adrenaline-induced ... eugenyl acetate - Kovats Retention Index - pherobase.com www.pherobase.com/database/kovats/kovats-detail-eugenyl%20acetate.php 2-Methoxy-4-(2-propenyl)-phenol acetate. Formula: C12H14O3. CAS#:, 93-28-7. MW: 206.24. Odour Characteristic: Fresh, Sweet, Woody, Clove, Floral, Spicy ...
