158 research outputs found
Supercritical CO2 extraction of Rosmarinus eriocalyx growing in Algeria: chemical composition and antioxidant activity of extracts and their solid plant materials
No full textSupercritical fluid extraction using carbon dioxide (SFE-CO2) is an eco-friendly, safe and effective extraction technique used on an industrial level to obtain flavour and fragrances as well as bioactive compounds from aromatic plants. In the present work, we investigated the SFE-CO2 extracts obtained from leaves and flowers of Rosmarinus eriocalyx, an aromatic shrub growing in Algeria and used similarly to R. officinalis. The SFE-CO2 extracts were obtained from R. eriocalyx using the following parameters: extraction time 180 min (including 30 min of static extraction), pressure 45 MPa; temperature 70°C. The chemical profiles of SFE-CO2 extracts were determined by gas chromatography-mass spectrometry (GC–MS). β-Amyrin and camphor were major compounds in the leaf extract, whereas tetradecenoic and linolenic acids were abundant in the flower extract. The amounts of tocopherols in the SFE-CO2 extracts were determined by high performance liquid chromatography (HPLC) analysis. Here, α-tocopherol attained noteworthy concentrations (8839 μg/g dw). The antioxidant activity of SFE-CO2 extract, plant powder and residue after SFE-CO2 extraction was assessed using three different methods, namely ABTS, FRAP and DPPH assays. The overall activity was as follows: plant powder > residue after SFE-CO2 extraction > SFE-CO2 extracts. Findings showed that R. eriocalyx is a rich source of antioxidant compounds, especially the plant material, and that considerable part of polar bioactive components still remain in the solid residue after SFE-CO2 extraction. Consequently, both lipophilic SFE-CO2 extract and antioxidant-rich extraction residues may be of interest for various industrial applications
Fakultetinės chirurgijos katedros įsteigimo Kauno Vytauto Didžiojo universitete 80-metį pasitinkant: istorinė Fakultetinės chirurgijos katedros ir klinikos Kaune apžvalga
No full textDepartment of Faculty Surgery in Kaunas was established in 1940 in Vytautas Magnus University. At that time the Dean of Medical Faculty and temporary chief of Surgery Department professor Vladas Lašas reorganized it by splitting and establishing two surgical departments – so called Faculty and Hospital Surgery. The Department has been renamed several times in subsequent years: until 1982 it continued to be Department of Faculty Surgery, in 1982–1992 was renamed to 2nd Surgery Department, in 1992–1998 carried the name of 2nd Surgery Clinic. This article offers an overview about prominent surgeons, who educated further generation of surgeons and created academic surgery, such as prof. V. Kanauka, prof. V. Lašas, A. Stropus, assoc. prof. J. Jaržemskas, assoc. prof. J. Karaliūnas, assoc. prof. J. Platūkis, prof. V. Zykas, prof. D. Venskutonis, also their collaborators and successors. The overview of academic, scientific progress as well as major contribution in the development of proctology in Lithuania is presented and includes the period until 1998 when Department underwent further reorganization by establishing new Department of General Surgery.akultetinės chirurgijos katedra buvo įsteigta 1940 m. Vytauto Didžiojo universitete Kaune. Ši katedra įkurta Medicinos fakulteto dekanui ir laikinajam Chirurgijos katedros vedėjui prof. Vladui Lašui reorganizavus tuo metu buvusią Chirurgijos katedrą į dvi atskiras – Fakultetinės chirurgijos ir Hospitalinės chirurgijos – katedras. Ilgainiui katedra keitė savo pavadinimus: iki 1982 m. (su pertrūkiais karo metu) ji išliko Fakultetinės chirurgijos katedra, 1982–1992 m. vadinosi II chirurgijos katedra, 1992–1998 – II chirurgijos klinika.
Straipsnyje apžvelgtos Fakultetinės chirurgijos katedros ištakos Nepriklausomoje Lietuvoje ir pirmieji akademinės chirurgijos kūrėjai, šiandienos chirurgų mokytojai ir asmenybės: prof. V. Kanauka, prof. V. Lašas, A. Stropus, taip pat katedros ir klinikos vadovai: doc. J. Jaržemskas, doc. J. Karaliūnas, doc. J. Platūkis, prof. V. Zykas, prof. D. Venskutonis bei jų kolegos ir mokiniai. Apžvelgiama Fakultetinės chirurgijos katedros akademinė ir mokslinė raida bei indėlis Lietuvoje plėtojant proktologiją, nušviečiamas laikotarpis iki 1998 m., kai, vykdant chirurgijos katedrų ir klinikų reorganizaciją, tuometiniame Kauno medicinos universitete įkurta Bendrosios chirurgijos klinika
Essential oils (EOs), pressurized liquid extracts (PLE) and carbon dioxide supercritical fluid extracts (SFE-CO2) from Algerian Thymus munbyanus as valuable sources of antioxidants to be used on an industrial level
No full textThe aim of this study was to demonstrate the potential of extracts from Algerian Thymus munbyanus as a valuable source of antioxidants for use on an industrial level. To this end, a study was conducted on the composition and antioxidant activities of essential oils (EOs), pressurized liquid extracts (PLE) and supercritical fluid extracts (SFE-CO2) obtained from Thymus munbyanus subsp. coloratus (TMC) and subsp. munbyanus (TMM). EOs and SFE-CO2 extracts were analysed by GC-FID and GC×GC-TOFMS revealing significant differences. A successive extraction of the solid SFE-CO2 residue by PLE extraction with solvents of increasing polarity such as acetone, ethanol and water, was carried out. The extracts were evaluated for total phenolic content by Folin–Ciocalteu assay, while the antioxidant power was assessed by DPPH, FRAP, and ORAC assays. SFE-CO2 extracts were also analysed for their tocopherol content. The antioxidant activity of PLE extracts was found to be higher than that of SFE-CO2 extracts, and this increased with solvent polarity (water > ethanol > acetone). Overall, these results support the use of T. munbyanus as a valuable source of substances to be used on an industrial level as preservative agents
Evaluation of the processes of isolation of lipids and proteins from hemp seeds and improvement of the obtained oil stability.
No full textHemp Seeds are a perfect and natural blend of easily digested proteins, essential fats (Omega 3 and 6), Gamma Linolenic Acid (GLA), antioxidants, amino acids, fiber, iron, zinc, carotene, phospholipids, phytosterols, vitamin B1, vitamin B2, vitamin B6, vitamin D, vitamin E, chlorophyll, calcium, magnesium, sulfur, copper, potassium, phosphorus, and enzymes [13]. The aim of this work is extraction of lipids, proteins and antioxidants from hemp seeds, evaluation and improvement of oxidative stability of obtained oil. Evaluation of antioxidant activity of extracts. Analyzation of protein composition and their functional properties. Determination of amino acids. Extracts from hemp seeds were obtained by choosing needed parameters and different solvents in different type of extractions. It was used supercritical CO2, Soxhlet extractions and cold pressing of hemp seeds to obtain lipids. Accelerated solvent extraction with different solvents (water, acetone, ethanol, water and ethanol solution) were used to obtain extracts from residue after supercritical CO2 extraction to evaluate their antioxidant activity. Protein extraction was done by Osborn. To obtain different protein fractions it was used different type of solvents: albumins – water, globulins – NaCl solution, prolamins – solution of water and ethanol, glutenins – NaOH solution. Antioxidant activity of extracts was evaluated by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS•+) scavenging, oxygen radical absorbance capacity (ORAC) assays, and DPPH radical scavenging assay. The total content of phenolic compounds in the extracts was determined using the Folin-Ciocalteu method. It was also measured tocopherol content. The stability of hemp seed oil and its solutions with antioxidants, expressed by induction period (IP) of their oxidation was determined using Oxipress and Rancimat methods. Induction period (IP) showed that that hemp oil with antioxidant DURALOX BLEND AN-110 XT (0,4 % concentration) has the best oxidative stability. It was evaluated, that the lowest peroxide concentration was in oil with antioxidant DURALOX OXIDATION MANAGEMENT (DOM), which was kept in fridge (4-5°C). The entire time of experiment (18 months), oil have not reached the critical value of peroxides at this conditions. The electrophoresis showed that the extracts contains proteins, whose molecular weight is between 20000 and 45000 Da. Comparing these results with the literature referred to, it was found that in these limits is protein Edestin molecular weight
Supercritical CO<sub>2</sub> Extraction of <i>Narcissus poeticus</i> L. Flowers for the Isolation of Volatile Fragrance Compounds
No full textThe flowers of Narcissus poeticus are used for the isolation of valuable fragrance substances. So far, as the majority of these substances consist of volatile and sensitive to heat compounds, there is a need of developing effective methods for their recovery. In this study, freeze-dried N. poeticus inflorescences were extracted with pure supercritical CO2 (SFE-CO2) and its mixture with 5% co-solvent ethanol (EtOH) at 40 °C. Extract yields varied from 1.63% (12 MPa) to 3.12% (48 MPa, 5% EtOH). In total, 116 volatile compounds were identified by GC-TOF/MS in the extracts, which were divided into 20 different groups. Benzyl benzoate (9.44–10.22%), benzyl linoleate (1.72–2.17%) and benzyl alcohol (0.18–1.00%) were the major volatiles among aromatic compounds. The amount of the recovered benzyl benzoate in N. poeticus SFE-CO2 extracts varied from 58.98 ± 2.61 (24 MPa) to 91.52 ± 1.36 (48 MPa) mg/kg plant dry weight (pdw). α-Terpineol dominated among oxygenated monoterpenes (1.08–3.42%); its yield was from 9.25 ± 0.63 (12 MPa) to 29.88 ± 1.25 (48 MPa/EtOH) mg/kg pdw. Limonene was the major monoterpene hydrocarbon; (3E)-hexenol and heneicosanol dominated among alcohols and phenols; dihydroactinidiolide and 4,8,12,16-tetramethyl heptadecan-4-olide were the most abundant lactones; heptanal, nonanal, (2E,4E)-decadienal and octadecanal were the most abundant aldehydes. The most important prenol lipids were triterpenoid squalene, from 0.86 ± 0.10 (24 MPa) to 7.73 ± 0.18 (48 MPa/EtOH) mg/kg pdw and D-α-tocopherol, from 1.20 ± 0.04 (12 MPa) to 15.39 ± 0.31 (48 MPa/EtOH) mg/kg pdw. Aliphatic hydrocarbons (waxes) constituted the main part (41.47 to 54.93%) in the extracts; while in case of a 5% EtOH the percentage of alkanes was the lowest. The fraction of waxes may be removed for the separation of higher value fragrance materials. In general, the results obtained are promising for a wider application of SFE-CO2 for the recovery of fragrance substances from N. poeticus flowers
Health Beneficial Phytochemicals in Dioscorea caucasica Lipsky Leaves and Tubers and Their Inhibitory Effects on Physiologically Important Enzymes
No full textDioscorea caucasica Lipsky is a tertiary relict endemic plant naturally growing in the western part of the trans-Caucasus regions; it has adapted and successfully grows in the temperate region of the Baltic countries. Information about its phytochemical composition and bioactivities is rather scarce. This study reports the results of the identification of 41 compounds in D. caucasica leaf and tuber hydroethanolic extracts using UPLC-QTOF/MS. Organic acids were found in both extracts; hydroxycinnamates and flavonoids were the main phytochemicals in the leaves, while steroidal glycosides, fatty acids (mainly hydroxylated) and carbohydrates were found in the tubers. Leaf extracts inhibited enzymes in a dose-dependent manner and were remarkably stronger inhibitors of physiologically important enzymes, namely α-amylase (48.6% at 480 µg/mL), α-glucosidase (IC(50) = 41.99 and 47.95 µg/mL with and without 0.1 M Na(2)CO(3)), acetylcholinesterase (45.85% at 100 µg/mL) and angiotensin-converting enzyme (IC(50) = 829.7 µg/mL), most likely due to the presence of some quantified polyphenolic antioxidants. The mode of inhibition of α-glucosidase and acetylcholinesterase was assessed via kinetic studies based on Lineweaver–Burk inhibition plots. Leaf and tuber extracts acted as mixed-type and competitive inhibitors of α-glucosidase, respectively; the leaf extract demonstrated an uncompetitive inhibition mode of acetylcholinesterase. It is expected that this new knowledge of D. caucasica will serve for its valorization in developing new health beneficial ingredients for functional foods and nutraceuticals
High-pressure extraction of antioxidant-rich fractions from shrubby cinquefoil (Dasiphora fruticosa L. Rydb.) leaves: process optimization and extract characterization /
No full textDasiphora fruticosa (basionym Potentilla fruticosa) is a shrub, known in traditional medicine for centuries. Due to the wide range of pharmacological effects, interest and applications of D. fruticosa extracts are continually increasing; however, reports on optimization of extraction conditions are scarce. Herein, a multi-step high-pressure extraction process with increasing polarity solvents was developed to isolate valuable fractions from D. fruticosa leaves. Supercritical CO2 extraction recovered 2.46 g/100 g of lipophilic fraction, rich in polyunsaturated fatty acids. Further, pressurized liquid extractions (PLE) with acetone, ethanol, and water were applied to obtain antioxidant-rich higher polarity extracts. Under optimized PLE conditions, the cumulative polar fraction yield was 29.98 g/100 g. Ethanol fraction showed the highest yield (15.3 g/100 g), TPC values (148.4 mg GAE/g), ABTS•+, and DPPH• scavenging capacity (161.1 and 151.8 mg TE/g, respectively). PLE was more efficient than conventional solid–liquid extraction in terms of extraction time, extract yields, and in vitro antioxidant capacity. Phytochemical characterization of PLE extracts by UPLCQ-TOF-MS revealed the presence of hyperoside, ellagic acid, among other health beneficial phenolic substances. Τhis study highlights the potential of high-pressure extraction techniques to isolate antioxidant-rich fractions from D. fruticosa leaves with multipurpose applications, including the prevention and treatment of chronic diseases
Characterization of steam volatiles and evaluation of the antioxidant properties of different extracts from leaves and roots of Aegopodium podagraria L /
No full textThis study presents the results on the composition of hydro-distilled essential oils and the antioxidant properties of extracts isolated with different polarity solvents from the leaves (GLEO) and roots (GREO) of wild-grown Lithuanian goutweed (Aegopodium podagraria L.). The yields of GLEO and GREO were 0.22% and 0.04%. The identified compounds numbered 117 and 88, which constituted 99.4 and 99.2% of the total integrated peak area, respectively. The major GLEO constituents were sesquiterpenes germacrene D (17.53%), (E)-β-bergamotene (11.75%), (E,E)-α-farnesene (7.23%), and (E)-caryophyllene (5.29%), while monoterpene α-pinene (19.24%) was quantitatively dominant in GREO, followed by sesquiterpenes germacrene B (4.59%), (E)-caryophyllene (4.51%), β-barbatene (4.26%), and β-bazzanene (4.10%). Polyacetylene (Z)-falcarinol, which is an important bioactive compound, constituted 4.60% in GREO. The antioxidant characteristics of water, methanol, and acetone extracts were evaluated by the TPC, DPPH•/ABTS•+ scavenging, and ORAC assays. The water and methanol extracts of the leaves were the strongest antioxidants; their TPC and ORAC values were 62.12 and 56.84 mg GAE/g, and 1426 and 1293 µM TE/g, respectively; the EC50 values of DPPH• and ABTS•+ scavenging were 1.18 and 2.48, and 2.45 and 3.57 mg/mL, respectively. The results obtained may assist in developing antioxidants, cosmeceuticals, nutraceuticals, and other health-beneficial preparations from A. podagraria extracts
Comparison of different extraction techniques for isolation of antioxidants from sweet grass (Hierochloe odorata)
No full textStrong antioxidants, 5,8-dihydroxycoumarin and 5-hydroxy-8-O-beta-D-glucopyranosyl-benzopyranone were extracted from sweet grass (Hierochloe odorata L.) by using Soxhlet (SE), microwave-assisted (MAE) and supercritical fluid carbon dioxide (SFE) extractions at different extraction schemes and parameters. One-step MAE gave the most concentrated extract with 8.15% of 5,8-dihydroxycoumarin (extract yield 0.42%). Comparable results were obtained by one-step SFE and Soxhlet extraction. A two-step extraction was applied in order to increase the concentration of active compounds. Taking into account antioxidant recovery and concentration as well the extraction time and environmental aspects, two-step SFE was considered as a preferable method. The obtained crude extract contained 20.31% of 5,8-dihydroxycoumarin and 2.18% of 5-hydroxy-8-O-beta-D-glucopyranosyl-benzopyranone. The extraction yields were 0.46 and 0.06%, respectively. First-step of SFE extraction was performed from dried herb at 35 MPa and 40degreesC with 20% of ethanol as a modifier; the second extraction step was performed from the crude extract at 25 MPa and 40degreesC
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