301 research outputs found
Apple scab control with grapefruit seed extract: no alternative to chemical fungicides
The growth inhibiting effect of four commercially available grapefruit seed extracts
on the causal organism of apple scab Venturia inaequalis was tested. Germination of
the conidia of Venturia inaequalis was pronouncedly inhibited by all tested extracts.
The commercial products were analyzed by high pressure liquid chromatography and
thin layer chromatography. All samples contained at least one preserving agent.
These substances were identified as either benzethonium chloride, benzalkonium
chloride, methyl parabene or propyl parabene. Freshly prepared extracts from seeds
of grapefruits (Citrus paradisi) did not inhibit the germination of Venturia inaequalis. It
was therefore concluded that the antifungal effect of grapefruit seed extracts is
caused by the added preservatives
Genuine and Sequestered Natural Products from the Genus Orobanche (Orobanchaceae, Lamiales)
The present review gives an overview about natural products from the holoparasitic genus Orobanche (Orobanchaceae). We cover both genuine natural products as well as compounds sequestered by Orobanche taxa from their host plants. However, the distinction between these two categories is not always easy. In cases where the respective authors had not indicated the opposite, all compounds detected in Orobanche taxa were regarded as genuine Orobanche natural products. From the about 200 species of Orobanche s.l. (i.e., including Phelipanche) known worldwide, only 26 species have so far been investigated phytochemically (22 Orobanche and four Phelipanche species), from 17 Orobanche and three Phelipanche species defined natural products (and not only natural product classes) have been reported. For two species of Orobanche and one of Phelipanche dedicated studies have been performed to analyze the phenomenon of natural product sequestration by parasitic plants from their host plants. In total, 70 presumably genuine natural products and 19 sequestered natural products have been described from Orobanche s.l.; these form the basis of 140 chemosystematic records (natural product reports per taxon). Bioactivities described for Orobanche s.l. extracts and natural products isolated from Orobanche species include in addition to antioxidative and anti-inflammatory effects, e.g., analgesic, antifungal and antibacterial activities, inhibition of amyloid β aggregation, memory enhancing effects as well as anti-hypertensive effects, inhibition of blood platelet aggregation, and diuretic effects. Moreover, muscle relaxant and anti-spasmodic effects as well as anti-photoaging effects have been described
Ethnopharmacology, phytochemistry, and bioactivities of Hieracium L. and Pilosella Hill (Cichorieae, Asteraceae) species
Ethnopharmacological relevance: Species of the genera Hieracium and Pilosella have been used in folk medicine for
centuries in many parts of the world. The most wiedly used species is P. officinarum Vaill., included in the British
and French Pharmacopoeias and sold as part of different commercial products.
Aim of the study: This review critically appraises the state-of-art of ethnopharmacology, specialised metabolites,
bioactivities, and toxicity of members of Hieracium and Pilosella. Thus, gaps in scientific knowledge can be
identified, also focusing on the development of products with pharmacological applications.
Materials and methods: Literature data of Hieracium and Pilosella species were mainly retrieved using different
electronic databases such as Web of Science, Google Scholar, SciFinder, and PubMed. Other electronic resources
included worldwide databases on ethnobotany, ethnopharmacology, and phytochemistry as well as government
reports. Additionally, ancient texts and local information such as PhD and MSc theses, and books were consulted.
Results: A comprehensive analysis of the above mentioned sources revealed that only 34 out of the about 850
described species within the genera Hieracium and Pilosella have been reported in the context of traditional
medicinal and ethnobotanical knowledge. The most often mentioned species is P. officinarum which has been
widely used due to its diuretic effects. Other popular uses of Hieracium and Pilosella species include the treatment
of skin, gastric, and intestinal diseases as well as respiratory and vascular ailments. Moreover, taxa of the two
genera have been used as antiobiotics, antiseptics, antidiabetics, tonics, antiepileptics, antiphlogistics, emetics,
wound healing drugs, astringents, haemostatics, and detoxificants. Finally, uses as a wild vegetable, fodder, plant
for hunting and for charming rituals have also been mentioned. Phytochemical research revealed a richness in
phenolic compounds and flavonoids. Moreover, coumarins, sesquiterpene lactones, terpenoids, and phytosterols
were found in Hieracium and Pilosella. Experimental research conducted to support traditional uses mainly
include in vitro tests, while assays based on in vivo models (including humans) are rather limited. Also, the vast
majority of the studies did not identify the compounds responsible for the detected bioactivities. These established
bioactivities include antidiabetic, anti-inflammatory, antibacterial, antimycotic, antiviral, cytotoxic and
antiproliferative, diuretic, gastroprotective, antiepileptic, hypotensive, anti-obesity, arthropodicidal, and skin
rejuvenating activities. Finally, limited toxicity studies have been conducted on members of Hieracium and
Pilosella.
Conclusion: Taxa belonging to Hieracium and Pilosella have been confirmed to exert diuretic, anti-inflammatory,
and antimicrobial effects, which is in line with their long traditional use. Moreover, the above mentioned fields of
application hint to the most promising routes for the development of new marketable products. Nonetheless,
additional data from an in-depth research on bio-active specialised metabolites such as sesquiterpenoids,
sesquiterpene lactones, and coumarines, their bioactivities and toxicity, and their biosynthesis are still
warranted.BiotecnologĂ
Chemical Diversity of Plant Cyanogenic Glycosides: An Overview of Reported Natural Products
Cyanogenic glycosides are an important and widespread class of plant natural products, which are however structurally less diverse than many other classes of natural products. So far, 112 naturally occurring cyanogenic glycosides have been described in the phytochemical literature. Currently, these unique compounds have been reported from more than 2500 plant species. Natural cyanogenic glycosides show variations regarding both the aglycone and the sugar part of the molecules. The predominant sugar moiety is glucose but many substitution patterns of this glucose moiety exist in nature. Regarding the aglycone moiety, four different basic classes can be distinguished, aliphatic, cyclic, aromatic, and heterocyclic aglycones. Our overview covers all cyanogenic glycosides isolated from plants and includes 33 compounds with a non-cyclic aglycone, 20 cyclopentane derivatives, 55 natural products with an aromatic aglycone, and four dihydropyridone derivatives. In the following sections, we will provide an overview about the chemical diversity known so far and mention the first source from which the respective compounds had been isolated. This review will serve as a first reference for researchers trying to find new cyanogenic glycosides and highlights some gaps in the knowledge about the exact structures of already described compounds
Natural Phenyldihydroisocoumarins: Sources, Chemistry and Bioactivity:
The present review gives an overview about naturally occurring phenyldihydroisocoumarins, their sources, and bioactivities. In total, 54 compounds are covered, including eight substances which are in fact alkaloids or protoalkaloids. These nitrogen containing compounds were exclusively found in the Papaveraceae family. The remaining 46 compounds have been reported from twelve different source families, ranging from mosses to angiosperms. Six of the nitrogen free compounds feature additional rings, while 40 are simple phenyldihydroisocoumarins with substituents in all possible positions, except 3, 2', and 6'. Common substituents of these simple phenyldihydroisocoumarins are hydroxy groups, methoxy groups, and glucosyloxy groups; on the other hand, acuminosyloxy and rutinosyloxy groups have so far been found only in one and two naturally occurring phenyldihydroisocoumarins, respectively. Though a number of bioactivities have been proven for phenyldihydroisocoumarins, ranging from anticancer and antidiabetic to antimicrobial and anti-inflammatory activities, so far only one taxon, Hydrangea macrophylla var. thunbergii, is widely used. Moreover, the usage of this taxon is mainly due to the sweet taste properties of the contained phenyldihydroisocoumarin phyllodulcin and less based on the alleged health-promoting effects of its constituents
Quantification of the total amount of black cohosh cycloartanoids by integration of one specific 1H NMR signal
Quantitative analysis is an important field in the quality control of medicinal plants, aiming to determine the amount of pharmacologically active constituents in complex matrices. Often biological effects of herbal drugs are not restricted to single compounds, but are rather caused by a number of often biogenetically related plant metabolites. Depending on the complexity of the analyzed plant extract, conflicts between accuracy, such as total content assays using photometric or colorimetric methods, and comprehensiveness, e.g. quantification of one or a few lead compounds can occur. In this study, we present a qHNMR approach determining the total amount of cycloartanoids in black cohosh (Actaea racemosa) rhizomes. Perdeuterated methanol containing 1,2,4,5-tetrachloro-3-nitrobenzene as an internal standard was used for extraction. Amounts of cycloartanoids were then measured by integrating 1H NMR signals of all cycloartenoids' H-19 exo protons. Due to their unusually low chemical shifts, these signals are well separated from all remaining signals in crude extracts. Thus, accurate (recovery rates of 99.5-102.5%) and precise (relative standard deviations below 2.5%) quantification of cycloartanoids was accomplished. To the best of our knowledge, this is the first example of a quantification of the total amount of a pharmacologically relevant compound class by integration of one 1H NMR signal characteristic for all members of this particular compound class. Additionally, we propose a new term and unit for the evaluation of medicinal plants and herbal medicinal products: the "specific partial amount of substance" of pharmacologically active constituents, indicated in mmol/g
UHPLC-HRMS Analysis of Fagus sylvatica (Fagaceae) Leaves: A Renewable Source of Antioxidant Polyphenols
European beech (Fagus sylvatica L.) is a deciduous tree, widely distributed in Europe and largely appreciated for its wood and nutritive nuts. Beech leaf also enjoys food use as salad, but an understanding of its nutraceutical value is still far from being achieved. Indeed, and also taking into account beech leaf as a consistent biomass residue available beechwood production and use, it needs to be explored as a valuable renewable specialized source of bioactive molecules. In this context, an untargeted ultra-high-performance liquid chromatography hyphenated with high resolution mass spectrometry (UHPLC-HRMS) approach was favorably applied to a beech leaf alcoholic extract, which also was evaluated for its antiradical capability (by means of assays based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and [2,2'-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid)] (ABTS) radical cation) and its ferric ion reducing power. Redox mitochondrial activity towards Caco-2 cells paved the way to explore the extract's capability to inhibit intracellular Reactive Oxygen Species (ROS) using 2',7'dichlorofluorescin diacetate (DCFH-DA) assay. Hydroxycinnamoyl derivatives, mainly belonging to the chlorogenic acid class, and flavonoids were the main constituents. Uncommon flavanone C-glycosides were also found, together with a plentiful flavonol diversity. Cell-free and cell-based assays highlight its dose-dependent antioxidant efficacy, providing a foundation for further investigation of beech leaf constituents and its valorization and use as a reservoir of bioactive natural products with potential nutraceutical applications
Phenolics from Rhagadiolus stellatus (Asteraceae, Cichorieae)
Rhagadiolus stellatus Gaertn., a Mediterranean member of the Cichorieae tribe of the Asteraceae family used as a food plant, was analyzed for its spectrum of phenolic compounds. Kaempferol 3-O-β-glucoside 1, kaempferol 3-O-β-rutinoside (nicotiflorin) 2, quercetin 3-O-β-glucoside 3, and luteolin 4 were isolated from the n-butanol layer of a methanolic extract of whole plants of Rh. stellatus of Spanish origin by repeated Sephadex LH-20 column chromatography. Structures were determined based on NMR and MS data as well as by comparison with literature data. Additionally, chlorogenic acid 5 and 3,5-dicaffeoylquinic acid 6 were detected by HPLC/DAD and HPLC/MS. Chemosystematic implications of the presented findings are discussed in comparison with other members of the Cichorieae tribe
UHPLC-ESI-QqTOF Analysis and In Vitro Rumen Fermentation for Exploiting Fagus sylvatica Leaf in Ruminant Diet
In recent years, animal husbandry has aimed at improving the conditions of livestock animals useful for humans to solve environmental and health problems. The formulation of animal feeds or supplements based on antioxidant plant compounds is considered a valuable approach and an alternative for livestock productivity. Forest biomass materials are an underestimated source of polyphenolic compounds whose sustainable recovery could provide direct benefits to animals and, indirectly, human nutrition. In this context, an alcohol extract from leaves of Fagus sylvatica L. was first investigated through an untargeted ultra-high-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) approach. Then, it was fractionated into a fatty acid-rich and a polyphenolic fraction, as evidenced by total lipid, phenol, and flavonoid content assays, with antiradical and reducing activity positively correlated to the latter. When tested in vitro with rumen liquor to evaluate changes in the fermentative parameters, a significant detrimental effect was exerted by the lipid-rich fraction, whereas the flavonoid-rich one positively modulated the production of volatile fatty acids (i.e., acetate, butyrate, propionate, etc.)
Antioxidants in Animal Nutrition: UHPLC-ESI-QqTOF Analysis and Effects on In Vitro Rumen Fermentation of Oak Leaf Extracts
: The genus Quercus supplies a large amount of residual material (e.g., bark, acorns, leaves, wood), the valorization of which can favor a supply of antioxidant polyphenols to be used in the pharmaceutical, nutraceutical, or cosmeceutical sector. The recovery of specialized metabolites could also benefit livestock feeding, so much so that polyphenols have gained attention as rumen fermentation modifiers and for mitigating the oxidative imbalance to which farm animals are subject. In this context, leaves of Quercus robur L. from Northern Germany were of interest and the alcoholic extract obtained underwent an untargeted profiling by means of ultra-high-performance liquid chromatography/high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) techniques. As triterpenes and fatty acids occurred, the alcoholic extract fractionation pointed out the obtainment of a polyphenol fraction, broadly constituted by coumaroyl flavonol glycosides and condensed tannins. Total phenol, flavonoid and condensed tannins content assays, as well as antiradical (DPPHâ—Ź and ABTS+â—Ź) and reducing activity (PFRAP) were carried out on the alcoholic extract and its fractions. When the effects on rumen liquor was evaluated in vitro in terms of changes in fermentation characteristics, it was observed that oak leaf extract and its fractions promoted an increase in total volatile fatty acids and differently modulated the relative content of each fatty acid
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