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Öğe Chemical and biological insights on aronia stems extracts obtained by different extraction techniques: From wastes to functional products(ELSEVIER SCIENCE BV, 2017) Cvetanovic, Aleksandra; Svarc-Gajic, Jaroslava; Zekovic, Zoran; Maskovic, Pavle; Durovic, Sasa; Zengin, Gökhan; Delerue-Matos, CristinaThe present study aimed to evaluate chemical and biological potential of aronia stems for providing new raw material for food and pharmaceutical industries. Aqueous extracts of aronia stems were prepared by three different techniques (microwave-assisted, ultrasound-assisted and subcritical water extraction). For biological activities, antioxidant, antimicrobial and cytotoxic activities were evaluated. For chemical characterisation, phenolic compounds and essential elements were analysed as well as total phenolic contents. Subcritical water extracts exhibited the strongest antioxidant activity with the highest content of phenolics. Minimum inhibitory concentrations for analysed extracts were in the range from 9.76 to 156.25 mu g/mL in antimicrobial assays. The extracts exerted prominent cytotoxicity against different cell lines. Rutin was detected as the major compound in the studied extracts and these extracts were also rich in essential elements. Our study suggested that subcritical water extract of aronia stem could be considered as a new raw material in developing novel functional/industrial products.Öğe The influence of the extraction temperature on polyphenolic profiles and bioactivity of chamomile (Matricaria chamomilla L.) subcritical water extracts(ELSEVIER SCI LTD, 2019) Cvetanovic, Aleksandra; Svarc-Gajic, Jaroslava; Zekovic, Zoran; Jerkovic, Jelena; Zengin, Gökhan; Gasic, Urog; Tesic, Zivoslav; Mašković, Pavle; Soares, Cristina; Barroso, M. Fatima; Delerue-Matos, Cristina; Đurović, SašaThe main goal of this research was to determine the relationship among chemical structure, bioactivity and temperature of chamomile during subcritical water extraction in isobaric conditions (45 bar) at seven different temperatures (65-210 degrees C). The influence of temperature on phenolic profiles was defined by UHPLC-HESI-MS/MS. The overall results indicate that the presence of conjugated double bonds, side chains, glucose moiety or ether moiety in molecules influence the efficiency of polyphenols' extraction in subcritical water. In terms of antioxidant activity, the extracts were the most active towards ABTS radicals (IC50 = 7.3-16.8 mu g/mL), whereby temperature of 150 degrees C was optimal. On the other hand, the extracts obtained at 115 degrees C showed highest cytotoxicity. Inhibition of alpha-amylase and alpha-glucosidase was the highest at 65 and 85 degrees C, i.e. 0.51 and 4.13 mmolAE/g, respectively. Activity against tyrosinase was the highest at 210 degrees C (17.92 mgKAE/g). The data showed that different non-phenolic compounds may also participate in bio-activities of the extracts.Öğe Isolation of apigenin from subcritical water extracts: Optimization of the process(ELSEVIER SCIENCE BV, 2017) Cvetanovic, Aleksandra; Svarc-Gajic, Jaroslava; Gasic, Uros; Tesic, Zivoslav; Zengin, Gökhan; Zekovic, Zoran; Durovic, SasaApigenin is a phytochemical which has been associated with numerous beneficial health effects. However, due to its low concentration and poor bioavailability, isolation from natural sources is very difficult. Subcritical water (SCW) is an excellent solvent for the extraction of moderately polar and non-polar flavonoids. Carefully balanced moderate hydrolytical potential of SCW was used in this work to liberate apigenin from its bound forms. In this research simultaneous extraction and hydrolysis of apigenin bound forms from chamomile have been performed. Optimal operation parameters for maximum yields of apigenin have been investigated and defined (solvent-to-sample ratio 1:30; agitation rate 3 Hz; pressure 45 bar; temperature 115 degrees C; time 30 min). Apigenin was further isolated in its pure form from water extracts obtained under optimal conditions using column chromatography. The purity of isolated compound was confirmed by spectroscopic analysis. Biological activity of extracts obtained under optimal conditions were determined as well. In order to identify polyphenolic compounds UHPLC-HESI-MS/MS analysis was performed. (C) 2016 Elsevier B.V. All rights reserved.Öğe A new source for developing multi-functional products: biological and chemical perspectives on subcritical water extracts of Sambucus ebulus L.(WILEY, 2018) Cvetanovic, Aleksandra; Zekovic, Zoran; Svarc-Gajic, Jaroslava; Razic, Slavica; Damjanovic, Ana; Zengin, Gökhan; Delerue-Matos, CristinaBACKGROUND: To obtain bioactive fractions from plant material subcritical water is notably advantageous in comparison to any other technique. Excellent solvating properties and selectivity combined with finely tuned reactivity of subcritical water enable exploitation of the potential of plants. Herein subcritical water extraction was used for recovery of bioactive compounds from leaves, roots and fruits of Sambucus ebulus L. Extracts obtained were characterized in terms of biological and chemical fingerprints. RESULTS AND DISCUSSIONR: esults obtained by using several antioxidant assays that focused on different mechanisms showed that subcritical water extracts of Sambucus ebulus were powerful antioxidants. Enzyme inhibitory effects were tested against alpha-amylase, alpha-glucosidase and tyrosinase, and the results showed the anti-diabetic potential of the extracts as well as its possible use with skin disorders. Antiproliferative properties were detected on three cell lines (A-549; LS-174 T; HeLa) and showed prominent cytotoxicity against all tumor cell lines. Inhibitory concentrations obtained were in the range 0.58-8.10 mu g mL(-1). Generally, the SCW extracts from leaves exhibited stronger biological activities with higher levels of phenolic compounds compared with the roots and fruits of Sambucus ebulus. Gallic acid, catechin and caffeic acid were identified as major components in these extracts and these components seem to relate with observed biological activity. CONCLUSION: The results obtained suggest that Sambucus ebulus has great potential for preparing new phyto-pharmaceuticals and functional food ingredients. (C) 2017 Society of Chemical Industry.
