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"Antioxidants"
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Correction: Hibiscus sabdariffa: Genetic variability, seasonality and their impact on nutritional and antioxidant properties
[This corrects the article DOI: 10.1371/journal.pone.0261924.].
Journal Article
Chemical Composition, Preliminary Toxicity, and Antioxidant Potential of IPiper marginatum/I Sensu Lato Essential Oils and Molecular Modeling Study
The essential oils (OEs) of the leaves, stems, and spikes of P. marginatum were obtained by hydrodistillation, steam distillation, and simultaneous extraction. The chemical constituents were identified and quantified by GC/MS and GC-FID. The preliminary biological activity was determined by assessing the toxicity of the samples to Artemia salina Leach larvae and calculating the mortality rate and lethal concentration (LC[sub.50]). The antioxidant activity of the EOs was determined by the DPPH radical scavenging method. Molecular modeling was performed using molecular docking and molecular dynamics, with acetylcholinesterase being the molecular target. The OES yields ranged from 1.49% to 1.83%. The EOs and aromatic constituents of P. marginatum are characterized by the high contents of (E)-isoosmorhizole (19.4–32.9%), 2-methoxy-4,5-methylenedioxypropiophenone (9.0–19.9%), isoosmorhizole (1.6–24.5%), and 2-methoxy-4,5-methylenedioxypropiophenone isomer (1.6–14.3%). The antioxidant potential was significant in the OE of the leaves and stems of P. marginatum extracted by SD in November (84.9 ± 4.0 mg TE·mL[sup.−1]) and the OEs of the leaves extracted by HD in March (126.8 ± 12.3 mg TE·mL[sup.−1]). Regarding the preliminary toxicity, the OEs of Pm-SD-L-St-Nov and Pm-HD-L-St-Nov had mortality higher than 80% in concentrations of 25 µg·mL[sup.−1]. This in silico study on essential oils elucidated the potential mechanism of interaction of the main compounds, which may serve as a basis for advances in this line of research.
Journal Article
A Study of the Chemical Composition, Antioxidant Potential, and Acute Toxicity of Bulgarian ITanacetum vulgare/I L. Essential Oil
Common tansy (Tanacetum vulgare L.) is a plant with medicinal properties that has traditionally been used in folk medicine for its anthelmintic, antispasmodic, and choleretic effects, for the treatment of diarrhea and digestive problems, and externally, as an insecticide in veterinary practices. In the current study, we investigated, for the first time, the chemical profile and antioxidant activity of essential oil from a wild population of T. vulgare L. growing in Bulgaria. Common tansy essential oil (EO), which is rich in bicyclic monoterpenes, was obtained using hydrodistillation and characterized by using gas chromatography–mass spectrometry (GC-MS). Thirty-seven compounds were identified in Bulgarian tansy EO. Among the major constituents were oxygenated monoterpenes, including compounds such as camphor (25.24%), trans-chrysantenyl acetate (18.35%), cis-verbenol (10.58%), thujone (6.06%), eucaliptol (5.99%), and α-campholenal (5.98%). The analysis results identified the essential oil from T. vulgare L. grown in the western Rhodope Mountains of Bulgaria as the camphor chemotype. Furthermore, its antioxidant activity was analyzed using the oxygen radical absorbance capacity (ORAC) method and was found to be 605.4 ± 49.3 µmol TE/mL. The essential oil was also tested for single-dose acute toxicity on Wistar rats and was found to be non-toxic by oral administration. The mean lethal dose by intraperitoneal administration was LD[sub.50] i.p. = 14.9 g/kg body weight. The results of the conducted study can serve as a basis for the evaluation and subsequent exploration of other pharmacotherapeutic effects of the essential oil obtained from the inflorescences of the Bulgarian species T. vulgare L.
Journal Article
Chemical Composition and In Vitro Antioxidant Activity of ISalvia aratocensis/I Essential Oils and Extracts
Salvia aratocensis (Lamiaceae) is an endemic shrub from the Chicamocha River Canyon in Santander (Colombia). Its essential oil (EO) was distilled from the aerial parts of the plant via steam distillation and microwave-assisted hydrodistillation and analyzed using GC/MS and GC/FID. Hydroethanolic extracts were isolated from dry plants before distillation and from the residual plant material after distillation. The extracts were characterized via UHPLC-ESI[sup.(+/−)]-Orbitrap-HRMS. The S. aratocensis essential oil was rich in oxygenated sesquiterpenes (60-69%) and presented τ-cadinol (44-48%) and 1,10-di-epi-cubenol (21-24%) as its major components. The in vitro antioxidant activity of the EOs, measured via an ABTS[sup.+*] assay, was 32-49 μmol Trolox[sup.®] g[sup.−1] and that measured using the ORAC assay was 1520-1610 μmol Trolox[sup.®] g[sup.−1]. Ursolic acid (28.9-39.8 mg g[sup.−1]) and luteolin-7-O-glucuronide (1.16-25.3 mg g[sup.−1]) were the major S. aratocensis extract constituents. The antioxidant activity of the S. aratocensis extract, obtained from undistilled plant material, was higher (82 ± 4 μmol Trolox[sup.®] g[sup.−1], ABTS[sup.+*]; 1300 ± 14 μmol Trolox[sup.®] g[sup.−1], ORAC) than that of the extracts obtained from the residual plant material (51-73 μmol Trolox[sup.®] g[sup.−1], ABTS[sup.+*]; 752-1205 μmol Trolox[sup.®] g[sup.−1], ORAC). S. aratocensis EO and extract had higher ORAC antioxidant capacity than the reference substances butyl hydroxy toluene (98 μmol Trolox[sup.®] g[sup.−1]) and α-tocopherol (450 μmol Trolox[sup.®] g[sup.−1]). S. aratocensis EOs and extracts have the potential to be used as natural antioxidants for cosmetics and pharmaceutical products.
Journal Article
Phytochemical Screening and Antioxidant Activity of Selected Estonian IGalium/I Species
The aim of the present study was to examine three different Galium species from the native population of Estonia, Galium verum, Galium aparine, and Galium mollugo, to characterise their non-volatile and volatile phytochemical composition and antioxidant activity. The main groups of bioactive compounds in the plants were quantified by colorimetric tests, showing high concentrations of polyphenols (up to 27.2 ± 1.5 mg GAE/g), flavonoids (up to 7.3 ± 0.5 mg QE/g) and iridoids (up to 40.8 ± 2.9 mg AE/g). The species were compared using HPLC-DAD-MS/MS, revealing some key differences in the phytochemical makeup of the extracts. The most abundant compound in the extracts of Galium verum blossoms and herb was found to be asperuloside, in Galium aparine herb, asperulosidic acid, and in Galium mollugo herb, chlorogenic acid. Additionally, the composition of volatile compounds was analysed by SPME-GC-MS. The degree of variability between the samples was high, but three volatiles, hexanal, anethole, and β-caryophyllene, were quantified (≥1%) in all analysed samples. The antioxidative activity of all extracts was evaluated using the ORAC[sub.FL] method, demonstrating that the Galium species from Estonia all exhibit strong antioxidant capacity (up to 9.3 ± 1.2 mg TE/g). Out of the extracts studied, Galium verum blossoms contained the highest amounts of bioactives and had the strongest antioxidant capacity.
Journal Article
INicotiana tabacum/I Leaf Waste: Morphological Characterization and Chemical-Functional Analysis of Extracts Obtained from Powder Leaves by Using Green Solvents
Tobacco cultivation and industrialization are characterized by the production of trillions of pre-harvest and post-harvest waste biomasses each year with the resulting negative effects on the environment. The leaves of blunt, pre-harvest waste, could be further used to obtain bioactive metabolites, i.e., polyphenols and alkaloids, for its potential cosmetic use. This study was conducted to obtain bio-compounds from pre-harvest tobacco leaf waste (var. Virginia) by applying conventional and green solvents (NaDES). Leaves and ground leaf waste were characterized based on their microscopic features. Conventional solvents, such as water, acetone, ethanol, and non-conventional solvents, such as Natural Deep Eutectic Solvents (NaDES), i.e., sucrose:lactic acid (LAS), frutose:glucose:sucrose (FGS), lactic acid:sucrose:water (SALA), choline chloride:urea (CU), and citric acid: propylene glycol (CAP) were used for bioactive extraction from tobacco waste powder. CU, FGS, and acetone/ethanol had similar behavior for the best extraction of alkaloids (6.37–11.23 mg ACE/g tobacco powder). LAS, FGS, SALA, and CU were more effective in phenolic compound extraction than conventional solvents (18.13–21.98 mg AGE/g tobacco powder). Because of this, LAS and SALA could be used to obtain phenolic-enriched extracts with lower alkaloid content rather than CU and FGS. Extracts of the powder obtained with conventional solvent or CU showed a high level of sugars (47 mg/g tobacco powder) The ABTS antioxidant capacity of tobacco leaf powder was higher in the extracts obtained with CU, FGS, and acetone (SC[sub.50] 1.6–5 µg GAE/mL) while H[sub.2]O[sub.2] scavenging activity was better in the extracts obtained with LAS, CAP and SALA (SC[sub.50] 3.8–8.7 µg GAE/mL). Due to the biocompatibility of the NaDES with the components of tobacco leaf waste, the opportunity to apply these extracts directly in antioxidant formulations, such as cosmetics, phytotherapic, and other formulations of topic use seems promising. Furthermore, NaDES constituents, i.e., urea and organic acid can also have beneficial effects on the skin.
Journal Article
Extraction of Bioactive Compounds from IC. vulgaris/I Biomass Using Deep Eutectic Solvents
C. vulgaris microalgae biomass was employed for the extraction of valuable bioactive compounds with deep eutectic-based solvents (DESs). Particularly, the Choline Chloride (ChCl) based DESs, ChCl:1,2 butanediol (1:4), ChCl:ethylene glycol (1:2), and ChCl:glycerol (1:2) mixed with water at 70/30 w/w ratio were used for that purpose. The extracts’ total carotenoid (TCC) and phenolic contents (TPC), as well as their antioxidant activity (IC50), were determined within the process of identification of the most efficient solvent. This screening procedure revealed ChCl:1,2 butanediol (1:4)/H[sub.2]O 70/30 w/w as the most compelling solvent; thus, it was employed thereafter for the extraction process optimization. Three extraction parameters, i.e., solvent-to-biomass ratio, temperature, and time were studied regarding their impact on the extract’s TCC, TPC, and IC50. For the experimental design and process optimization, the statistical tool Response Surface Methodology was used. The resulting models’ predictive capacity was confirmed experimentally by carrying out two additional extractions under conditions different from the experimental design.
Journal Article
Chemical Composition and Biological Activities of IPrangos ferulacea/I Essential Oils
Prangos ferulacea (L.) Lindl, which belongs to the Apiaceae family, is a species that mainly grows in the eastern Mediterranean region and in western Asia. It has been largely used in traditional medicine in several countries and it has been shown to possess several interesting biological properties. With the aim to provide new insights into the phytochemistry and pharmacology of this species, the essential oils of flowers and leaves from a local accession that grows in Sicily (Italy) and has not yet been previously studied were investigated. The chemical composition of both oils, obtained by hydrodistillation from the leaves and flowers, was evaluated by GC-MS. This analysis allowed us to identify a new chemotype, characterized by a large amount of (Z)-β-ocimene. Furthermore, these essential oils have been tested for their possible antimicrobial and antioxidant activity. P. ferulacea essential oils exhibit moderate antimicrobial activity; in particular, the flower essential oil is harmful at low and wide spectrum concentrations. They also exhibit good antioxidant activity in vitro and in particular, it has been shown that the essential oils of the flowers and leaves of P. ferulacea caused a decrease in ROS and an increase in the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) in OZ-stimulated PMNs. Therefore, these essential oils could be considered as promising candidates for pharmaceutical and nutraceutical preparations.
Journal Article