Search results for "plant extracts"
showing 10 items of 510 documents
Quantification of phenolic acids by partial least squares Fourier-transform infrared (PLS-FTIR) in extracts of medicinal plants.
2020
Introduction Phenolic compounds are ubiquitous compounds found in all plants as their secondary metabolites. Phenols are becoming increasingly important particularly because of their beneficial effects on health. Objective To provide a faithful calibration model for the simultaneous determination and quantification of phenolic acids, as salicylic, vanillic, p-hydroxybenzoic acids, eugenol and thymol in different extracts of medicinal plants, a comparative study was made between two methods of infrared measurements based on attenuated total reflectance (ATR) and transmission. Methods Characteristic absorbance peak heights of mid-infrared spectra of individual phenolic acids were measured for…
Uso di alcuni estratti vegetali come bio-erbicidi
2014
Le infestanti competono con le piante coltivate per la luce, gli elementi nutritivi, l'acqua e lo spazio, e influenzano fortemente le produzioni agrarie sia sotto l'aspetto quantitativo che qualitativo. Normalmente le infestanti riescono ad assorbire e utilizzare l'acqua e gli elementi nutritivi più rapidamente ed efficacemente delle colture principali, accrescendosi più velocemente di queste, fino, talvolta, ad inibirne del tutto lo sviluppo. Nel corso del tempo, alcune infestanti hanno sviluppato meccanismi di resistenza agli erbicidi comunemente utilizzati. Questa acquisizione, unitamente alla necessità di reperire soluzioni al problema della gestione delle infestanti anche in condizioni…
Crotonic acid as a bioactive factor in carrot seeds (Daucus carota L.)
2004
Water extracts from the carrot seed (Daucus carota L.) var. Perfekcja exhibit plant growth inhibitory properties against cress, cucumber, onion and carrot in a dose-dependant manner. This property results from the action of low-and high-molecular components of the extract. The low-molecular component was identified as crotonic acid ((E)-2-butenoic acid). Its presence was also confirmed in other late varieties of carrot. The determined strong herbicidal properties of crotonic acid and its availability after release to soil combined with its high level in seeds suggest that it might be considered as an allelopathic and autotoxic factor in the seeds.
Resveratrol, a polyphenolic phytoalexin present in red wine, enhances expression and activity of endothelial nitric oxide synthase.
2002
Background— Estrogens can upregulate endothelial nitric oxide synthase (eNOS) in human endothelial cells by increasing eNOS promoter activity and enhancing the binding activity of the transcription factor Sp1. Resveratrol, a polyphenolic phytoalexin found in grapes and wine, has been reported to act as an agonist at the estrogen receptor. Therefore, we tested the effect of this putative phytoestrogen on eNOS expression in human endothelial cells. Methods and Results— Incubation of human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells with resveratrol for 24 to 72 hours upregulated eNOS mRNA expression in a time- and concentration-dependent manner (up to 2.8-fold)…
Simultaneous determination of main phenolic acids and flavonoids in tomato by micellar electrokinetic capillary electrophoresis
2017
[EN] A methodology for the determination of tomato phenolic acids and flavonoids has been developed combining MEKC and DAD detection. The influence on polyphenol separation of pH and background electrolyte, BGE (borax, acetonitrile, methanol and SDS concentrations), was studied and optimized using response surface methodology and weighted desirability function. Separation of polyphenols was achieved within 20 min at 15 degrees C using 11.3 mM borax and 11.2 mM SDS adjusted to pH 8.5 as BGE. Validation was performed using standards and tomato extracts. Recoveries ranged from 77 to 106%. Acceptable repeatabilities were obtained for peak area (% RSD <3.1% and <3.7%) and migration times (% RSD …
Fixed oil from seeds of narrow-leaved ash (F. angustifolia subsp. angustifolia): Chemical profile, antioxidant and antiproliferative activities.
2019
Fraxinus angustifolia subsp. angustifolia is a plant with an age-old use for the production of manna. However, it is also a valuable source of fixed oil rich-seeds. In the present study we examined the chemical and biological properties of this oil in order to support a possible application in foodstuffs, nutraceuticals and cosmetics. Fatty acid composition, volatile and phenolic substances were evaluated. Oleic and linoleic acid represented 45.5% and 50.0%, respectively, of the total fatty acid composition. Among polar phenolic substances identified (secoiridoids, phenylethanoid glycosides, phenolic acids and alcohols, flavonoids, coumarins) isoverbascoside is for the first time reported i…
Biologically active properties of plant extracts in cosmetic emulsions
2020
Abstract Describes biologically active properties waters plant extracts of domestic herbaceous species as a part cosmetic emulsion in this article. In particular, the antioxidant features related to vitamins, flavonoids, coloring, extractive and tannins were reported. The following research methods as qualitative analysis on groups of biologically active substances, thin-layer chromatography, titrimetry and photometry were used in the work. The ability of extracts to influence the physico-chemical, organoleptic and antioxidant properties of cosmetic emulsion samples was established. The ability of the extracts to exhibit antioxidant and prooxidant effects in cosmetic emulsion samples was de…
Chemical Composition, In Vitro Bioaccessibility and Antioxidant Activity of Polyphenolic Compounds from Nutraceutical Fennel Waste Extract
2021
Fennel (Foeniculum vulgare Mill.) waste contains a broad range of bioactive molecules, including polyphenols, which have poor bioaccessibility during gastrointestinal digestion. This work aimed to investigate the bioaccessibility of total phenolic compounds and the antioxidant capacity during simulated gastrointestinal digestion using two nutraceutical formulations based on non-acid-resistant (NAR) and acid-resistant (AR) capsules containing aqueous-based extracts from fennel waste. Moreover, to obtain a comprehensive investigation of the polyphenolic constituents of the fennel waste extract, a high-resolution mass spectrometry (Q-Orbitrap) analysis was performed. Notably, chlorogenic acids…
Anti-inflammatory and antioxidant activity of polyphenolic extracts from Lactuca sativa (var. Maravilla de Verano) under different farming methods
2015
BACKGROUND: Besides their nutritional value, vegetables are a source of health-promoting compounds, such as polyphenols, and their content can be influenced by the particular farming method. In this study polyphenolic extracts from Lactuca sativa (var. Maravilla de verano) plants cultivated with different farming methods were chemically characterised and tested in vitro and ex vivo inflammation models.RESULTS: The tested extacts (250-2.5 µg mL(-1) ) were able to reduce both the inflammatory and oxidative stress in LPS-stimulated J774A.1 murine monocyte macrophage cells, by lowering the release of nitric oxide (NO) and reactive oxygen species (ROS) and promoting nuclear translocation of nucl…
Antioxidant activity of TunisianGeranium robertianumL. (Geraniaceae)
2013
The present investigation focuses on the methanolic extract obtained from Geranium robertianum L. (Geraniaceae) (Herb Robert), a herbal plant used in traditional medicine for the treatment of human and animal diseases. The antioxidant capacities of the extract were evaluated using 1,1-diphenyl-2- picrylhydrazyl radical, β-carotene/linoleic acid and reducing power and metal chelating activity assays. The amount of total phenolic content, flavonoids and condensed tannins was very high, and the correlation between the antioxidant activity potential and total phenolic level of the extract was pointed out.