Browsing by Author "Valentão, Patrícia"
Now showing 1 - 8 of 8
Results Per Page
Sort Options
- Accumulation of phenolic compounds in in vitro cultures and wild plants of Lavandula viridis L'Her and their antioxidant and anti-cholinesterase potentialPublication . Costa, Patrícia; Gonçalves, Sandra; Valentão, Patrícia; Andrade, Paula B.; Romano, AnabelaIn this study, we evaluated the phenolic profile, antioxidant and anti-cholinesterase potential of different extracts from wild plants and in vitro cultures of Lavandula viridis L'Her. The HPLC-DAD analysis allowed the identification and quantification of 3-0-caffeoylquinic, 4-0-caffeoylquinic, 5-0-caffeoylquinic and rosmarinic acids, and luteolin and pinocembrin. Water/ethanol extract from in vitro cultures contained the highest amount of the identified phenolic compounds (51652.92 mg/kg). To investigate the antioxidant activity we used Trolox equivalent antioxidant capacity, oxygen radical absorbance capacity, Fe2+ chelation activity and the inhibition of Fe2+-induced lipid peroxidation in mouse brain homogenates (in vitro). Overall, all the extracts from both wild plants and in vitro cultures exhibited ability to scavenge free radicals, to chelate Fe2+ and to protect against lipid peroxidation. In addition, the extracts from L. viridis were active in inhibiting both acetylcholinesterase and butyrylcholinesterase (Ellman's method). Our findings suggest that L. viridis in vitro cultures represent a promising alternative for the production of active metabolites with antioxidant and anti-cholinesterase activity. (C) 2013 Elsevier Ltd. All rights reserved.
- Changes on organic acid secretion and accumulation in Plantago almogravensis Franco and Plantago algarbiensis Samp. under aluminum stressPublication . Martins, Neusa; Gonçalves, Sandra; Andrade, Paula B.; Valentão, Patrícia; Romano, AnabelaWe investigated the effect of Al (400 M) on organic acids secretion, accumulation and metabolism in Plantago almogravensis Franco and Plantago algarbiensis Samp. Al induced a significant reduction on root elongation only in P. algarbiensis. Both species accumulated considerable amounts of Al(>120 g g−1) in their tissues, roots exhibiting the highest contents (>900 g g−1). Al stimulated malonic acid secretion in P. algarbiensis, while citric, succinic and malic acids were secreted by P. almogravensis. Moreover, Al uptake was accompanied by substantial increases of citric, oxalic, malonic and fumaric acids contents in the plantlets of either species. Overall, the acid metabolizing enzymes were not directly involved in the Al induced organic acid secretion and accumulation. Our data suggest that Al detoxification in P. almogravensis implies both secretion of organic acids from roots and tolerance to high Al tissue concentrations, while in P. algarbiensis only the tolerance mechanism seems to be involved.
- Chemical profiling and biological screening of Thymus lotocephalus extracts obtained by supercritical fluid extraction and hydrodistillationPublication . Costa, Patrícia; Gonçalves, Sandra; Grosso, Clara; Andrade, Paula B.; Valentão, Patrícia; Bernardo-Gil, Maria Gabriela; Romano, AnabelaEssential oil and extracts from the aerial parts of Thymus lotocephalus were obtained by hydrodistillation (HD) and supercritical fluid extraction (SFE) in two different collectors, respectively. SFE was conducted at 40 ◦C and a working pressure of 12 or 18 MPa. The chemical profiles were determined using GC-FID and GC–IT–MS. Oxygen-containing monoterpenes were the primary constituents in the essential oil and SFE extracts collected in the second separator, while the extracts obtained in the first separator were predominantly oxygen-containing sesquiterpenes. A large number of compounds were identified by hydrodistillation and, in contrast, the highest extraction yields were obtained using SFE. Linalool(10.43 ± 1.63%) was the main component in essential oil, whereas camphor (7.91 ± 0.84%) and cis-linalool oxide (7.25 ± 1.45%) were the major compounds in the extracts-2nd separator obtained at pressures of 12 and 18 MPa, respectively. Caryophyllene oxide was the primary constituent identified in the extracts-1st separator (4.34 ± 0.51 and 4.41 ± 1.25% obtained at 12 and 18 MPa, respectively). The antioxidant activity was assessed by ORAC and DPPH assays, and the anti-cholinesterase activity was evaluated in vitro using Ellman’s method. The essential oil and SFE extracts (first separator) of T. lotocephalus possessed antioxidant activity and strongly inhibited cholinesterases. We also demonstrated that the acetylcholinesterase and butyrylcholinesterase inhibitory activities of the essential oil could be attributed to 1,8-cineole and caryophyllene oxide, respectively.
- Inhibitory effect of Lavandula viridis on Fe2+-induced lipid peroxidation, antioxidant and anti-cholinesterase propertiesPublication . Costa, Patrícia; Gonçalves, Sandra; Andrade, Paula B.; Valentão, Patrícia; Romano, AnabelaIn this research, the total phenolic content of a Lavandula viridis methanol extract was evaluated and the phenolic identification and quantification was assessed. Rosmarinic acid and luteolin-7-O-glucoside were the two major compounds identified by HPLC–DAD (ca. 39 and 13 g/kg, respectively). This extract showed a strong antioxidant activity in ORAC (2858.39 ± 70.97 lmolTE/gextract) and TEAC (967.18 ± 22.57 lmolTE/gextract) assays, as well as Fe2+ chelating and OH scavenging abilities. Furthermore, the extract prevented Fe2+-induced lipid peroxidation, by reducing MDA content in mouse brains(in vitro), and inhibited AChE and BChE activities both in vitro and in vivo. These findings demonstrate that the methanol extract from L. viridis is a potential source of natural antioxidants and cholinesterase inhibitors.
- Metabolic profile and biological activities of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco: Studies on the essential oil and polar extractsPublication . Costa, P.; Gonçalves, Sandra; Valentão, Patrícia; Andrade, Paula B.; Almeida, C.; Nogueira, J. M. F.; Romano, AnabelaWe investigated the metabolic profile and biological activities of the essential oil and polar extracts of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco collected in south Portugal. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that oxygen-containing monoterpenes was the principal group of compounds identified in the essential oil. Camphor (40.6%) and fenchone (38.0%) were found as the major constituents. High-performance liquid chromatography with diode array detection (HPLC-DAD) analysis allowed the identification of hydroxycinnamic acids (3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and rosmarinic acids) and flavones (luteolin and apigenin) in the polar extracts, with rosmarinic acid being the main compound in most of them. The bioactive compounds from L. pedunculata polar extracts were the most efficient free-radical scavengers, Fe2+ chelators and inhibitors of malondialdehyde production, while the essential oil was the most active against acetylcholinesterase. Our results reveal that the subspecies of L. pedunculata studied is a potential source of active metabolites with a positive effect on human health. © 2013 Elsevier Ltd. All rights reserved.
- QuincePublication . Duarte, Amílcar; Grosso, Ana Clara; Valentão, Patrícia; Andrade, Paula B.The quince tree is native to a wide area that includes Caucasus, Transcaucasia and Central Asia (Georgia, Armenia, Azerbaijan, Uzbekistan, Turkmenistan, Tajikistan, Iran, Afghanistan and Pakistan). Nowadays, there are still wild quince plants in Dagestan, Azerbaijan, Turkmenia and Iran (Zhukovsky, 1964; Postman, 2012). During ancient times, quince spread from its centre of origin to the east, to the region of the Himalaya Mountains, and has been cultivated for thousands of years in central Asia and in the Middle East. It was also grown on the islands of ancient Greece. The name "Cydonia" was assigned to the quince probably due to the name of an ancient city-state ("Cydonia" or "KYDONIA") of Crete, where the quince was abundantly grown in the 1st century BC. The Romans cultivated quince on a large scale and studied the plant, having described different cultivars. Quince is naturalized throughout the Mediterranean, temperate regions of Asia and southern and central regions of Europe. It is currently cultivated in many European countries (up to Scotland and Norway), North and South Africa, North and South America, Australia and Oceania. It is the sole member of the genus Cydonia, but various subspecies and forms have been described (Lobachev and Korovina, 1981).
- Supercritical fluid extraction and hydrodistillation for the recovery of bioactive compounds from Lavandula viridis L’HérPublication . Costa, Patrícia; Grosso, Clara; Gonçalves, Sandra; Andrade, Paula B.; Valentão, Patrícia; Bernardo-Gil, Maria Gabriela; Romano, AnabelaThe chemical profiles of bioactive essential oil and extracts obtained by hydrodistillation (HD) and supercritical fluid extraction (SFE), respectively, from Lavandula viridis were compared. The SFE was performed at 40 C and at extraction pressures of 12 or 18 MPa in two different separators. Evaluation of the essential oil and SFE extracts by GC–FID and GC–IT–MS revealed that oxygen-containing monoterpenes were the major constituents in both cases, but there were important differences between the chemical profiles produced by the different extraction techniques. More compounds were isolated by HD but higher yields were achieved by SFE. Camphor was the main component identified in the essential oil (31.59 ± 1.32%), and in extracts from the first (1.61 ± 0.34%) and second SFE separators (22.48 ± 1.49%) at 12 MPa. In contrast, the first separator SFE extract at 18 MPa (heavy compounds) was dominated by myrtenol(5.38 ± 2.04%) and camphor (4.81 ± 1.93%), whereas the second separator SFE extract (volatiles) was dominated by verbenone (13.97 ± 5.27%). The essential oil and heavy compound extracts from the first separator possessed antioxidant and anti-cholinesterase activities. Our data show that phytochemicals from the aerial parts of L. viridis could be developed as natural antioxidant and anti-cholinesterase drugs, with particular applications in the symptomatic treatment of Alzheimer’s disease.
- Thymus lotocephalus wild plants and in vitro cultures produce different profiles of phenolic compounds with antioxidant activityPublication . Costa, Patrícia; Gonçalves, Sandra; Valentão, Patrícia; Andrade, Paula B.; Coelho, Natacha; Romano, AnabelaWe compared the phenolic metabolites and antioxidant activities of Thymus lotocephalus G. López & R.Morales wild plants and in vitro cultures using different extraction solvents. HPLC–DAD analysis allowed the identification and quantification of phenolic (caffeic and rosmarinic) acids and flavones (luteolin and apigenin) in extracts from both sources. The in vitro cultures accumulated large amounts of rosmarinic acid. However, extracts from both sources were able to neutralise free radicals in different test systems(TEAC and ORAC assays), to form complexes with Fe2+ and to protect mouse brains against Fe2+-induced lipid peroxidation. The solvent significantly influenced the phenolic content and antioxidant activity of the extracts, water/ethanol being the most efficient for the extraction of antioxidant phytochemicals. We conclude that in vitro cultures of T. lotocephalus represent a promising alternative for the production of valuable natural antioxidants and an efficient tool for the in vitro biosynthesis of rosmarinic acid, therefore avoiding the need to exploit populations of wild plants.