Vieira, VanessaPrieto Lage, Miguel A.Barros, LillianCoutinho, João A.P.Ferreira, Isabel C.F.R.Ferreira, Olga2018-02-122018-02-122017Vieira, Vanessa; Prieto, Miguel; Barros, Lillian; Coutinho, João A.P.; Ferreira, Isabel C.F.R.; Ferreira, Olga (2017). Polyols based solvents for the extraction of phenolic compounds from Juglans regia L. leaves. In 10º Encontro Nacional de Cromatografia. Bragança. ISBN 978-972-745-234-7978-972-745-234-7http://hdl.handle.net/10198/15666In this work, a set of polyols was selected to be used as solvents for the extraction of phenolic compounds from Juglans regia L. (walnut) leaves. Their biocompatibility and low toxicity makes them an interesting option with potential industrial applications in the cosmetic, pharmaceutical or food areas. In fact, some of them are already used as cosmetic ingredients and/or can be obtained from renewable raw materials [1, 2]. Walnut leaves are an important source of bioactive molecules, such as phenolic compounds, suggesting that their extracts (or pure components) could be used as natural antioxidants in different applications, e.g. to replace synthetic antioxidants such as BHT (2,6-di-tert-butyl-4-methylphenol) or in dermatological bases preventing oxidative damage [3,4]. Hence, the extraction performance of glycerol and a series of diols (1,2-etanodiol, 1,2-propanediol, 1,3- propanediol, 1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol) was screened and the phenolic profile, characterized by HPLC-DAD. To evaluate the response, only the main bioactive compounds present in the extract (acid 3-O-caffeyloquinic acid, quercetin 3-O-glucoside and quercetin O-pentoside) were considered. In a second phase, for comparison purposes, the most promising polyols were selected to prepare betaine based deep eutectic mixtures. After selecting the best solvent, the remaining extraction conditions (time, temperature and water content) were further optimized. These results provide relevant information for the design of an extraction process of phenolic compounds from J. regia leaves using alternative solvents that could also play a role as a formulation medium.engconference object