166 research outputs found
LC-ESI-MS/MS as a tool for chemical characterization of edible and medicinal plants
No full textNatural products play a significant role in the drug discovery for the treatment of human diseases. A large number of bioactive compounds is produced by plants and among studied plants about 20% have been used for pharmaceutical purposes [1]. Moreover, the consumption of fruits and vegetables is highly recommended due to their medicinal properties and high nutritional value [2]. For this reason, a rapid detection of biologically active substances plays a key role in the chemical investigation of phyto-preparations. Crude plant extracts are very complex mixtures and the isolation process is a time consuming task [3]. The development of techniques such as high performance liquid chromatography coupled to photodiode array/UV (LC-PDA/UV) and to mass spectrometer (LC-MS or LC-MS/MS) has provided highly selective and sensitive methods for the chemical analysis of complex herbal mixtures, by allowing a rapid structural determination of known plant constituents with only a low amount of sample [4]. In this talk, the chemical characterization of phyto-preparations from several Mediterranean medicinal and edible plants, showing interesting biological activities, is presented, with particular regard to their phenolic content. Analyses were performed using a LC-PDA/UV-MS system and the electrospray ionization (ESI) technique combined with multi-stage tandem mass spectrometry (MSn). With the acquisition of complementary spectral and chromatographic data on detected components, the major constituents of studied herbal mixtures were identified providing the chemical profiles of biological active extracts. 1. Newman DJ, Cragg GM. Natural products as sources of new drugs from 1981 to 2014. J Nat Prod 2016; 79:629-61. 2. Altemimi A, Lakhssassi N, Baharlouei A, Watson DG, Lightfoot DA. Phytochemicals: extraction, isolation, and identification of bioactive compounds from plant extracts. Plants (Basel) 2017;6:42. 3. Wolfender JL, Terreaux C, Hostettmann K. The importance of LC-MS and LC-NMR in the discovery of new lead compounds from plants. Pharm Biol 2000;38:41-54. 4. Steinmann D, Ganzera M. Recent advances on HPLC/MS in medicinal plant analysis. J Pharm Biomed Anal 2011;55:744-57
Cedrela and Toona genera: a rich source of bioactive limonoids and triterpenoids
No full textCedrela P. Browne is a genus of trees, strictly related to Toona, in the Meliaceae, a family of flowering plants in the order Sapindales, which is among the most diverse sources of secondary metabo- lites in the Angiospermae. The most abundant metabolites in these genera are limonoids, tetranor- triterpenes possessing diverse structural features, apotirucallanes, tirucallanes, and other triterpenes. The chemical constituents isolated from the genera Cedrela and Toona over the past decades, together with their biological activities, have been compiled in this article. The allelochemical and the phytotoxic activity of limonoids and triterpenoids seem to play a crucial role in the ecological function of these metabolites. While, the most promising use in human field seems related to their antimalarial and anti- inflammatory effects, even that further investigation are still needed
Pregnane glycosides from Caralluma genus
No full textPregnane glycosides are a class of naturally occurring substances widely distributed in the plant kingdom and in some marine organisms. They closely resemble cardiac glycosides which are important in medicinal chemistry due to their digitalis-like effects on cardiac muscles. The use of pregnane glycosides in herbal drugs and folk medicines has generated great interest in the chemical characterization of these molecules for their possible therapeutic properties.
Herein we report the phytochemical and biological studies carried out on pregnane glycosides from several species of Caralluma (Asclepiadaceae family), a genus of succulent perennial herbs that grow wild in stony habitats of Subtropical and Tropical region of the world. The species investigated until now were C. dalzielii, C. indica, C. lasiantha, C. negevensis, C. penicillata, C. retrospiciens, C. russeliana, C. stalagmifera, C. tuberculata, and C. umbellata with a total of 108 pregnanes, aglycons or glycosides, isolated and characterized from the
apolar and polar extracts of the title plants
Phenolics of Arbutus unedo L. (Ericaceae) Fruits: Identification of Anthocyanins and Gallic acid Derivatives
No full textArbutus unedo L., the strawberry tree (Ericaceae family), is an evergreen shrub or small tree, typical of the Mediterranean fringe and climate. The aim of the present study was to evaluate the profile of the phenolic constituents of A. unedo fruits. Seven compds. were purified by Sephadex LH-20 column chromatog. of the MeOH ext. followed by HPLC and were characterized as arbutin, β-D-glucogalline, gallic acid 4-O-β-D-glucopyranoside, 3-O-galloylquinic acid, 5-O-galloylquinic acid, 3-O-galloylshikimic acid, and 5-O-galloylshikimic acid, by NMR and ESI-MS analyses. Moreover, LC-PDA-MS anal. of the red pigment of A. unedo fruits revealed the presence of 3 anthocyanins recognized as cyanidin 3-O-β-D-galactopyranoside, delphinidin 3-O-β-D-glucopyranoside, and cyanidin 3-O-β-D-arabinopyranoside. These pigments were also quantified
Costituents of Conceveiba guianensis (Euphorbiaceae)
No full textThe ground dried leaves of Conceveiba guianensis Aubletwere extd. and analyzed. The secondary metabolites obtained from C. guianensis could be all grouped into shikimic acid and gallic acid derivs. and flavonoids, both flavonol O-glycosides and C-glycosyl flavones. In particular, the isolation of apigenin 8-C-(2"-galloyl)-beta-D-glucopyranoside is reported now for the first time in a plant of the tribe Acalypheae and generally in the Euphorbiaceae famil
Profiling specialized metabolites of two Malus domestica Borkh. varieties: In vitro pulp callus culture vs fruit peel and pulp
No full textMalus domestica Borkh. (Rosaceae) comprises different varieties of commercially widespread apples around the world and available on the market all year round. Given their economic and traditional importance, chemical profile of these fruits was thoroughly investigated defining apples as a source of different classes of phytochemicals with interesting biological properties. Enhancing the production of these bioactive molecules by in vitro culture techniques is of great importance for avoiding problems due to their availability, but also to express selectively some metabolites. Based on previous results showing apple pulp callus culture as good source of pentacyclic triterpenic acids, the aim of this work was to investigate the specialized metabolites produced by optimized callus cultures starting from explants of pulp fruits of two apple varieties (‘Annurca’ and the still unexplored ‘Mela Rosa del Montefeltro’) compared to those of ripe fruit pulps and peels. LC-MS/MS analyses of fruit and callus hydroalcoholic extracts allowed the identification of 72 compounds, including hydroxycinnamic acids, catechins, flavonoids, and triterpenes. The qualitative profile of peels and pulps were very similar, while differences were observed in the callus extracts. Pulps were rich in phenols including phlorizin, catechin, and procyanidins; peels contained both phenols and triterpenic acids while callus extracts were characterized only by highly produced triterpenic acids, some of which were not found in the fruits. In conclusion, this study sheds light on how cell plant culture can be considered as an alternative system for producing specialized metabolites
Flavonoides de Exellodendron coriaceum (Chrysobalanaceae). Actividad Hipoglicemiante
No full textChrysobalanaceae es una familia de plantas superiores, que crece principalmente en las regiones tropicales y subtropicales y que está constituida por 17 géneros y más de 400 especies. En Venezuela están reportados 7 géneros, cinco de los cuales han sido estudiados desde el punto de vista químico y su actividad biológica, por nuestros grupos de investigación, desde el año 1993. Los resultados indican que estas plantas son ricas en Flavonoides y triterpenos y además son poseedoras de diferentes actividades biológicas, entre las que cabe destacar: antiviral, citotóxica, antibacterial, leishmanicida, hipotensora, antioxidante e hipoglicemiante.
En el presente trabajo, presentamos es estudio de Exellodendron coriaceum (Benth.). Reportamos el aislamiento de siete Flavonoides del extracto n-butanòlico, de las partes aéreas de E.coreaceum. Los primeros cuatro compuestos fueron identificados como: quercetina-3-O-β-D-galactopyranosido (1), quercetina-3-O-α-L-arabinopyranosido (2), quercetina-3-O-α-Lrhamnopyranosyl-(1→2)-α-L-rhamnopyranosido (3), y quercetina-3-O-α-L-rhamnopyranosyl-(1→6)-β-Dgalactopyranosido (4), mientras que los restantes, debido a la poca cantidad de muestra, fueron caracterizados parcialmente, como derivados metoxilados y/o glicosilados de quercetina con glucosa, galactosa o arabinosa, como restos de azúcar. Los Flavonoides 3 y 4, son reportados por primera vez en la familia.
Todos los compuestos fueron ensayados con el método de Glucosa 6 fosfatasa. Los resultados indican una actividad inhibitoria de la enzima, cuando se usan microsomas intactos, con un porcentaje del 65%. De acuerdo a nuestro conocimiento, este es el primer reporte sobre la química y actividad biológica de E. coriaceum
Oleanane Saponins from Stylosanthes erecta.
No full textFive new oleanane saponins (1-5) together with 4 know flavonol glycosides were isolated from the aerial parts of S. erecta. Their structures were elucidated by 1D and 2D NMR expts. including 1D-TOCSY, DQF-COSY, ROESY, HSQC, and HMBC spectroscopy, as well as ESI-MS anal. The aglycon moieties of 1-4 were assigned as new oleanane derivs
Allelopathic potential of Avena sativa L. (oat) var. Argentina: bioassay-guided isolation of allelochemicals
No full textThe term allelopathy, first introduced by Molisch in 1937, refers to chemical interactions among plants, including those mediated by microorganisms [1]. Allelopathy may be further defined as an important mechanism of plant interference mediated by the addition of plant–produced secondary products to the rhizosphere [2]. During the last 30 years, the potential implications of allelopathy for agriculture, like insect, pest and weed management, have been described and discussed in detail [3]. Chemicals with allelopathic potential are present in nearly all plants and their respective tissues, including leaves, stems, roots, flowers, seeds, bark, and buds. These phytotoxins may be released into the environment in sufficient quantities to affect the growth of neighboring plants [4]. Nearly every class of secondary products or metabolites has been implicated in allelopathic interference [3]. In the literature is reported that oats are resistant to a number of important crop diseases and are grown in crop rotation to limit build up of pathogens [5]. In this work we investigated the allelopathic potential of Avena sativa L. (oat) var. Argentina by bioassay-guided isolation of allelochemicals, after field experiments. They indicated the allelophatic activity of this plant against several weed species. Aerial parts of oat were extracted and fractionated on the basis of phytotoxic activity on lettuce seeds. The active fraction was successively analyzed by LC-PDA-ESI-MS/MS analysis leading to identification of compounds with allelophatic propriety, corresponding to a flavonoid mixture of isoorientin 2-O-glucoside, vitexin 2”-O-arabinoside and isovitexin 2”-O-arabinoside
Chemical profile of Festuca arundinacea extract showing allelochemical activity
No full textThe allelopathic potential of fescue (Festuca arundinacea Shreb.) was investigated under field and laboratory conditions. In the field, incorporation of fescue aboveground biomass into the soil provided an effective weed control as it significantly reduced both the number and the dry weight of all weed species. The effect on weeds was species specific. The reduction of the most abundant species, Picris echioides, with respect to the number of individuals and their dry weight was 67 and 45%. Fescue aboveground biomass, harvested immediately before soil incorporation, was utilized in a bioassay-oriented fractionation, aimed at identifying the compounds in the toxic extracts of the plant. While phytotoxic activity was detected for the n-butanol fraction, no activity was found for the aqueous one. Germination of an indicator species, lettuce (Lactuca sativa L.), was reduced by 33% at the higher extract concentration of 20 mg/mL, owing to the increase of the number of abnormal seedlings. The LC/MS profile of the extract revealed the presence of two alkaloids, seven flavonol glycosides, and two flavonol aglyca. Quercetin 3-O-rutinoside, isorhamnetin 3-O-rutinoside, and kaempferol 3-O-rutinoside were reported in fescue for the first time
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