Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Nat Prod Res ; : 1-6, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-38073526

RESUMEN

The leaves of Monteverdia ilicifolia (syn. Maytenus ilicifolia) are widely used in traditional South American medicine to treat gastrointestinal problems such as gastritis and ulcers. Several herbal products containing the leaves of M. ilicifolia can be found in the market. However, other species with similar leaf morphology are confounding materials, e.g. Monteverdia aquifolia (Celastraceae), Citronella gongonha (Cardiopteridaceae), Jodina rhombifolia (Santalaceae), Sorocea bonplandii (Moraceae) and Zollernia ilicifolia (Fabaceae). This study aimed to identify M. ilicifolia and distinguish it from its potential adulterants using high-performance thin-layer chromatography (HPTLC) technique. Comprehensive HPTLC analysis revealed specific fingerprints that can be used to assess the minimum content of epicatechin and the quality of commercial espinheira-santa samples. The results of the study demonstrated that the HPTLC method is capable of detecting adulterations and distinguishing M. ilicifolia from all confounding materials in commercial products available on the market, showing that most of the products are of poor quality due to adulterations.

2.
Microsc Microanal ; 29(5): 1809-1821, 2023 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-37639710

RESUMEN

The leaves of Monteverdia ilicifolia (syn. Maytenus ilicifolia), commonly called espinheira-santa, are widely used in South American traditional medicines to treat gastritis and ulcers. Several products labeled as espinheira-santa are sold as dietary supplements in retail stores and via e-commerce. Many different species with similar leaf morphology are often mistaken for Monteverdia ilicifolia and used as espinheira-santa, including Monteverdia aquifolia (Celastraceae), Citronella gongonha (Cardiopteridaceae), Jodina rhombifolia (Santalaceae), Sorocea bonplandii (Moraceae), and Zollernia ilicifolia (Fabaceae). This study aimed to characterize M. ilicifolia and distinguish it from adulterants using morphological and microscopic techniques. In addition, foreign matter and powder characteristics of botanical materials sold as "espinheira-santa" were analyzed. The morphoanatomical studies of the leaves and stems of M. ilicifolia and its five adulterant species have revealed noteworthy features that can help species identification and quality control of commercial espinheira-santa. This study showed that many commercial espinheira-santa materials were adulterated and of inferior quality.


Asunto(s)
Celastraceae , Maytenus , Brasil , Microscopía , Control de Calidad , Extractos Vegetales
3.
Int J Biol Macromol ; 229: 825-837, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36592847

RESUMEN

Bufadienolides are steroids that inhibit Na+/K+-ATPase; recent evidence shows that bufalin inhibits the activity of porcine aminopeptidase N (pAPN). We evaluated the selectivity of some bufadienolides on metallo-aminopeptidases. Among the enzymes of the M1 and M17 families, pAPN and porcine aminopeptidase A (pAPA) were the only targets of some bufadienolides. ѱ-bufarenogin, telocinobufagin, marinobufagin, bufalin, cinobufagin, and bufogenin inhibited the activity of pAPN in a dose-dependent manner in the range of 10-7-10-6 M. The inhibition mechanism was classical reversible noncompetitive for telocinobufagin, bufalin and cinobufagin. Bufogenin had the lowest Ki value and a non-competitive behavior. pAPA activity was inhibited by ѱ-bufarenogin, cinobufagin, and bufogenin, with a classical competitive type of inhibition. The models of enzyme-inhibitor complexes agreed with the non-competitive type of inhibition of pAPN by telocinobufagin, bufalin, cinobufagin, and bufogenin. Since APN is a target in cancer therapy, we tested the effect of bufadienolides on the MeWo APN+ human melanoma cell line; they induced cell death, but we obtained scant evidence that inhibition of APN contributed to their effect. Thus, APN is a selective target of some bufadienolides, and we suggest that inhibition of APN activity by bufadienolides is not a major contributor to their antiproliferative properties in MeWo cells.


Asunto(s)
Bufanólidos , Melanoma , Humanos , Porcinos , Animales , Antígenos CD13 , Aminopeptidasas , Bufanólidos/farmacología , Bufanólidos/metabolismo , Inhibidores Enzimáticos , Melanoma/tratamiento farmacológico , Mamíferos/metabolismo
4.
Molecules ; 27(6)2022 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-35335288

RESUMEN

In this study, the in vitro antimicrobial, antiparasitic, antiproliferative and cytotoxic activities of essential oil from Baccharis parvidentata Malag. (EO-Bp) and Lippia origanoides Kunth (EO-Lo) were explored. The relevant effects were observed against the parasitic protozoans Plasmodium falciparum, Trypanosoma cruzi, Trypanosoma brucei and Leishmania amazonensis (ranging 0.6 to 39.7 µg/mL) and malignant MCF-7, MCF-7/HT, 22Rv1, and A431 cell lines (ranging 6.1 to 31.5 µg/mL). In parallel, EO-Bp showed better selective indexes in comparison with EO-Lo against peritoneal macrophages from BALB/c mice and MRC-5 cell line. In conclusion, EO-Lo is known to show a wide range of health benefits that could be added as another potential use of this oil with the current study. In the case of EO-Bp, the wide spectrum of its activities against protozoal parasites and malignant cells, as well as its selectivity in comparison with non-malignant cells, could suggest an interesting candidate for further tests as a new therapeutic alternative.


Asunto(s)
Baccharis , Lippia , Aceites Volátiles , Trypanosoma cruzi , Animales , Brasil , Ratones , Aceites Volátiles/farmacología
5.
Molecules ; 26(7)2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33805445

RESUMEN

Stevia rebaudiana (Bertoni) Bertoni is a plant species native to Brazil and Paraguay well-known by the sweet taste of their leaves. Since the recognition of rebaudioside A and other steviol glycosides as generally recognized as safe by the United States Food and Drug Administration in 2008 and grant of marketing approval by the European Union in 2011, the species has been widely cultivated and studied in several countries. Several efforts have been dedicated to the isolation and structure elucidation of minor components searching for novel non-caloric sugar substitutes with improved organoleptic properties. The present review provides an overview of the main chemical approaches found in the literature for identification and structural differentiation of diterpene glycosides from Stevia rebaudiana: High-performance Thin-Layer Chromatography, High-Performance Liquid Chromatography, Electrospray Ionization Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy. Modification of diterpene glycosides by chemical and enzymatic reactions together with some strategies to scale up of the purification process saving costs are also discussed. A list of natural diterpene glycosides, some examples of chemically modified and of enzymatically modified diterpene glycosides reported from 1931 to February 2021 were compiled using the scientific databases Google Scholar, ScienceDirect and PubMed.


Asunto(s)
Diterpenos , Glicósidos , Stevia/química , Cromatografía Líquida de Alta Presión/métodos , Cromatografía en Capa Delgada/métodos , Diterpenos/química , Diterpenos/aislamiento & purificación , Glicósidos/química , Glicósidos/aislamiento & purificación , Espectroscopía de Resonancia Magnética/métodos , Espectrometría de Masa por Ionización de Electrospray/métodos
6.
Molecules ; 26(4)2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33669312

RESUMEN

Diabetes mellitus is a chronic disease and one of the fastest-growing health challenges of the last decades. Studies have shown that chronic low-grade inflammation and activation of the innate immune system are intimately involved in type 2 diabetes pathogenesis. Momordica charantia L. fruits are used in traditional medicine to manage diabetes. Herein, we report the purification of a new 23-O-ß-d-allopyranosyl-5ß,19-epoxycucurbitane-6,24-diene triterpene (charantoside XV, 6) along with 25ξ-isopropenylchole-5(6)-ene-3-O-ß-d-glucopyranoside (1), karaviloside VI (2), karaviloside VIII (3), momordicoside L (4), momordicoside A (5) and kuguaglycoside C (7) from an Indian cultivar of Momordica charantia. At 50 µM compounds, 2-6 differentially affected the expression of pro-inflammatory markers IL-6, TNF-α, and iNOS, and mitochondrial marker COX-2. Compounds tested for the inhibition of α-amylase and α-glucosidase enzymes at 0.87 mM and 1.33 mM, respectively. Compounds showed similar α-amylase inhibitory activity than acarbose (0.13 mM) of control (68.0-76.6%). Karaviloside VIII (56.5%) was the most active compound in the α-glucosidase assay, followed by karaviloside VI (40.3%), while momordicoside L (23.7%), A (33.5%), and charantoside XV (23.9%) were the least active compounds. To better understand the mode of binding of cucurbitane-triterpenes to these enzymes, in silico docking of the isolated compounds was evaluated with α-amylase and α-glucosidase.


Asunto(s)
Antiinflamatorios/farmacología , Simulación por Computador , Frutas/química , Glicósidos/química , Glicósidos/farmacología , Hipoglucemiantes/farmacología , Momordica charantia/química , Triterpenos/química , Triterpenos/farmacología , Animales , Antiinflamatorios/química , Bioensayo , Espectroscopía de Resonancia Magnética con Carbono-13 , Glicósidos/aislamiento & purificación , Hipoglucemiantes/química , Ligandos , Ratones , Conformación Molecular , Simulación del Acoplamiento Molecular , Espectroscopía de Protones por Resonancia Magnética , Células RAW 264.7 , ARN Mensajero/genética , ARN Mensajero/metabolismo , Triterpenos/aislamiento & purificación , alfa-Amilasas/química , alfa-Amilasas/metabolismo , alfa-Glucosidasas/química , alfa-Glucosidasas/metabolismo
7.
Bioorg Med Chem ; 27(14): 3097-3109, 2019 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-31196754

RESUMEN

Bitter melon (Momordica charantia) has been used to manage diabetes and related conditions in various parts of the world. In the present study, ten compounds were isolated from acetone and methanol extracts of bitter melon. The chemical structures of compounds were unambiguously elucidated by 1D, 2D NMR, and high-resolution mass spectra. Identified compounds 1-7 exhibited significant inhibition of α-amylase and moderate inhibition of α-glucosidase activities. Momordicoside G and gentisic acid 5-O-ß-d-xyloside showed the highest inhibition of α-amylase (70.5%), and α-glucosidase (56.4%), respectively. Furthermore, molecular docking studies of isolated compounds 1-7 were able to bind to the active sites of both enzymes. Additionally, the isolated compounds 1-7 significantly attenuated lipopolysaccharide (LPS)-induced inflammation, downregulating the expression of pro-inflammatory markers NF-κB, INOS, IL-6, IL-1ß, TNF-α, and Cox-2 in murine macrophage RAW 264.7 cells. One phenolic derivative, gentisic acid 5-O-ß-d-xyloside, was isolated and identified for the first time from bitter melon, and significantly suppressed the expression of Cox-2 and IL-6 compared to the LPS-treated group. α-Amylase and α-glucosidase are targets of anti-diabetes drugs, our findings suggest that compounds purified from bitter melon may have potential to use as functional food ingredients for the prevention of type 2 diabetes and related inflammatory conditions.


Asunto(s)
Antiinflamatorios/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Inflamación/tratamiento farmacológico , Momordica charantia/química , Antiinflamatorios/farmacología , Simulación por Computador , Hipoglucemiantes/farmacología
8.
Bioorg Chem ; 87: 31-42, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30856374

RESUMEN

Momordica charantia L., commonly known as bitter melon, belongs to the Cucurbitaceae family. Various in vitro and in vivo studies have indicated that extracts of bitter melons have anti-diabetic properties. However, very little is known about the specific purified compounds responsible for these antidiabetic properties. In the present study, 3ß,7ß,25-trihydroxycucurbita-5,23(E)-dien-19-al, charantal, charantoside XI, and 25ξ-isopropenylchole-5, 6-ene-3-O-d-glucopyranoside were isolated from bitter melon fruit. The structures of the purified compounds were elucidated by HR-ESIMS, 1D, and 2D NMR experiments. All compounds exhibited significant inhibition of α-amylase and α-glucosidase comparable to acarbose. Molecular docking studies demonstrated that purified compounds were able to bind to the active sites of proteins. Additionally, the purified compounds showed significant anti-inflammatory activity, downregulating the expression of NF-κB, iNOS, IL-6, IL-1ß, TNF-α, and Cox-2 in lipopolysaccharide-activated macrophage RAW 264.7 cells. Our findings suggest that the purified compounds have potential anti-diabetic and anti-inflammatory activities and therefore hold promise for the development of plant-based management for diabetic and inflammatory conditions.


Asunto(s)
Antiinflamatorios/farmacología , Inhibidores Enzimáticos/farmacología , Glicósidos/farmacología , Hipoglucemiantes/farmacología , Momordica charantia/química , Triterpenos/farmacología , Animales , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/aislamiento & purificación , Glicósidos/química , Glicósidos/aislamiento & purificación , Hipoglucemiantes/química , Hipoglucemiantes/aislamiento & purificación , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Simulación del Acoplamiento Molecular , Estructura Molecular , Células RAW 264.7 , Relación Estructura-Actividad , Triterpenos/química , Triterpenos/aislamiento & purificación , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/metabolismo , alfa-Glucosidasas/metabolismo
9.
Molecules ; 24(5)2019 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-30813648

RESUMEN

The discovery of potent natural and ecofriendly pesticides is one of the focuses of the agrochemical industry, and plant species are a source of many potentially active compounds. We describe the bioassay-guided isolation of antifungal and phytotoxic compounds from the ethyl acetate extract of Ambrosia salsola twigs and leaves. With this methodology, we isolated and identified twelve compounds (four chalcones, six flavonols and two pseudoguaianolide sesquiterpene lactones). Three new chalcones were elucidated as (S)-ß-Hydroxy-2',3,4,6'-tetrahydroxy-5-methoxydihydrochalcone (salsolol A), (S)-ß-Hydroxy-2',4,4',6'-tetrahydroxy-3-methoxydihydrochalcone (salsolol B), and (R)-α, (R)-ß-Dihydroxy-2',3,4,4',6'- pentahydroxydihydrochalcone (salsolol C) together with nine known compounds: balanochalcone, six quercetin derivatives, confertin, and neoambrosin. Chemical structures were determined based on comprehensive direct analysis in real time-high resolution mass spectrometry (HR-DART-MS), as well as 1D and 2D NMR experiments: Cosy Double Quantum Filter (DQFCOSY), Heteronuclear Multiple Quantum Coherence (HMQC) and Heteronuclear Multiple Bond Coherence (HMBC), and the absolute configurations of the chalcones were confirmed by CD spectra analysis. Crystal structure of confertin was determined by X-ray diffraction. The phytotoxicity of purified compounds was evaluated, and neoambrosim was active against Agrostis stolonifera at 1 mM, while confertin was active against both, Lactuca sativa and A. stolonifera at 1 mM and 100 µM, respectively. Confertin and salsolol A and B had IC50 values of 261, 275, and 251 µM, respectively, against Lemna pausicotata (duckweed). The antifungal activity was also tested against Colletotrichum fragariae Brooks using a thin layer chromatography bioautography assay. Both confertin and neoambrosin were antifungal at 100 µM, with a higher confertin activity than that of neoambrosin at this concentration.


Asunto(s)
Ambrosia/química , Fungicidas Industriales/aislamiento & purificación , Fungicidas Industriales/farmacología , Herbicidas/aislamiento & purificación , Herbicidas/farmacología , Dicroismo Circular , Colletotrichum/efectos de los fármacos , Fungicidas Industriales/química , Herbicidas/química , Lactuca/efectos de los fármacos , Estructura Molecular , Extractos Vegetales/análisis , Hojas de la Planta/química , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Difracción de Rayos X
10.
Nat Prod Res ; 33(13): 1876-1884, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29889557

RESUMEN

A silica gel orthogonal method using acetonitrile: water was developed for the analyses of fractions rich in very polar steviol glycosides and resolve regions of co-elution of these compounds in reversed-phase. Additionally, we also used this normal phase analytical method to scale up the purification process of steviol glycosides. Using these approaches, one novel minor tetra-glucopyranosyl diterpene glycosides together with three known compounds were purified from a commercial Stevia rebaudiana leaf extract. Compound 1 was unambiguously elucidated as 13-[(2-O-ß-D-glucopyranosyl-ß-D-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(6-O-ß-D-glucopyranosyl-ß-D-glucopyranosyl) ester (rebaudioside Y) based on high-performance liquid chromatography retention times, tandem mass spectrometry dissociation pattern and 1D and 2D NMR experiments. Known compounds were isolated in gram quantities and identified as rebaudioside D, E and M.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Diterpenos de Tipo Kaurano/análisis , Glucósidos/análisis , Diterpenos de Tipo Kaurano/aislamiento & purificación , Glicósidos/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Gel de Sílice , Stevia/química , Espectrometría de Masas en Tándem , Trisacáridos/aislamiento & purificación
11.
Molecules ; 23(12)2018 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-30558268

RESUMEN

Stevia rebaudiana and its diterpene glycosides are one of the main focuses of food companies interested in developing novel zero calorie sugar substitutes since the recognition of steviol glycosides as Generally Recognized as Safe (GRAS) by the United States Food and Drug Administration. Rebaudioside A, one of the major steviol glycosides of the leaves is more than 200 times sweeter than sucrose. However, its lingering aftertaste makes it less attractive as a table-top sweetener, despite its human health benefits. Herein, we report the purification of two novel tetra-glucopyranosyl diterpene glycosides 1 and 3 (rebaudioside A isomers) from a commercial Stevia rebaudiana leaf extract compounds, their saponification products compounds 2 and 4, together with three known compounds isolated in gram quantities. Compound 1 was determined to be 13-[(2-O-ß-d-glucopyranosyl-6-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl) oxy]ent-kaur-16-en-19-oic acid-ß-d-glucopyranosy ester (rebaudioside Z), whereas compound 3 was found to be 13-[(2-O-ß-d-glucopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl) oxy]ent-hydroxyatis-16-en-19-oic acid -ß-d-glucopyranosy ester. Two new tetracyclic derivatives with no sugar at position C-19 were prepared from rebaudiosides 1 and 3 under mild alkaline hydrolysis to afford compounds 2 13-[(2-O-ß-d-glucopyranosyl-6-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl) oxy]ent-kaur-16-en-19-oic acid (rebaudioside Z1) and 4 13-[(2-O-ß-d-glucopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl) oxy]ent-hydroxyatis-16-en-19-oic acid. Three known compounds were purified in gram quantities and identified as rebaudiosides A (5), H (6) and J (7). Chemical structures were unambiguously elucidated using different approaches, namely HRESIMS, HRESI-MS/MS, and 1D-and 2D-NMR spectroscopic data. Additionally, a high-quality crystal of iso-stevioside was grown in methanol and its structure confirmed by X-ray diffraction.


Asunto(s)
Diterpenos/química , Extractos Vegetales/química , Stevia/química , Espectroscopía de Resonancia Magnética con Carbono-13 , Glicosilación , Espectroscopía de Protones por Resonancia Magnética
12.
J Sep Sci ; 40(19): 3771-3781, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28762654

RESUMEN

As an aid for structure elucidation of new steviol glycosides, reversed-phase C18 high-performance liquid chromatography method was developed with several previously characterized diterpene glycosides, to identify known and detect novel aglycone-C13 oligosaccharide moieties and indirectly identify C-19 interlinkages. Elution order of several diterpene glycosides and their aglycone-C13 oligosaccharide substituted with different sugar arrangements were also summarized. Comparison of the retention time of a product obtained after alkaline hydrolysis with the aglycone-C-13 portions of known compounds reported herein allowed us to deduce the exact positions of the sugars in the C-13 oligosaccharide portion. The elution position of several steviol glycosides with an ent-kaurene skeleton was helpful to describe an identification key. Two previously uncharacterized diterpene glycosides together with two known compounds were isolated from a commercial Stevia rebaudiana leaf extract. One was found to be 13-[(2-O-ß-d-xylopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(2-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl) ester (rebaudioside V), whereas the other was determined to be 13-[(2-O-ß-d-xylopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(2-O-α-l-rhamnopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl) ester (rebaudioside W). Previously reported compounds were isolated in gram quantities and identified as rebaudioside J and rebaudioside H. In addition, a C-19 sugar-free derivative was also prepared from rebaudioside H to afford rebaudioside H1 . Chemical structures were partially determined by the high-performance liquid chromatography method and unambiguously characterized by using one-dimensional and two-dimensional nuclear magnetic resonance experiments.


Asunto(s)
Cromatografía Líquida de Alta Presión , Diterpenos/análisis , Glicósidos/análisis , Oligosacáridos/análisis , Stevia/química
13.
Rapid Commun Mass Spectrom ; 31(3): 315-324, 2017 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-27862504

RESUMEN

RATIONALE: Steviol glycosides with an ent-kaurene core are being used in the Food Industry as non-caloric sweeteners. These compounds are chemically similar in terms of sugar types and sugar arrangements. In order to assign sugar positions, we describe herein the dissociation pattern for steviol glycosides under varying collision energies. METHODS: Steviol glycosides (1 mg/mL, 2 µL) were automatically injected into the mass spectrometer by direct infusion using a 100-well tray autosampler. The mass spectrometric analysis was performed using a quadrupole time-of-flight (QTOF) tandem mass spectrometer (model #G6530A; Agilent Technologies, Palo Alto, CA, USA) equipped with an electrospray ionization (ESI) source with Jet Stream technology. RESULTS: Dissociation of several natural and prepared steviol glycosides was carefully studied by ESI-QTOF-MS/MS using a range of collision energies: 10, 20, 30, 40, 50, 60, 70 and 80 eV. This procedure allowed us to establish the dissociation pattern for steviol glycosides, and thus the sugar arrangement in the branched oligosaccharide portion linked at position C-13 of steviol, and also infer the sugar arrangement at C-19. CONCLUSIONS: Those steviol glycosides with a monosaccharide or less hindered disaccharides at position C-19 are cleaved at low collision energy (10 eV) while highly hindered disaccharides and trisaccharides are cleaved at 40 eV. However, sugars attached at C-13 cleave at highest collision energies in the following order: the C-3 sugar, followed by the C-2 sugar and finally the sugar directly linked at C-13. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Diterpenos de Tipo Kaurano/análisis , Diterpenos de Tipo Kaurano/química , Glucósidos/análisis , Glucósidos/química , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masas en Tándem/métodos , Modelos Moleculares
14.
Phytochemistry ; 135: 106-114, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27979591

RESUMEN

Two diterpene glycosides were isolated from a commercial Stevia rebaudiana leaf extract. One was found to be 13-[(2-O-ß-d-glucopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(2-O-ß-d-xylopyranosyl-3-O-ß-d-glucopyranosyl- ß-d-glucopyranosyl) ester (rebaudioside T), whereas the other was determined to be 13-[(2-O-ß-d-glucopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(6-O-α-l-arabinopyranosyl-ß-d-glucopyranosyl) ester (rebaudioside U). In addition, five C-19 sugar free derivatives were prepared and identified as follows: 13-[(2-O-α-l-rhamnopyranosyl-ß-d-glucopyranosyl)]oxy]kaur-16-en-19-oic acid (dulcoside A1); 13-[(2-O-ß-d-xylopyranosy-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl)oxy]kaur-16-en-19-oic acid; 13-[(2-O-ß-d-xylopyranosyl-ß-d-glucopyranosyl-)oxy]kaur-16-en-19-oic acid; 13-[(2-O-ß-d-glucopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-xylopyranosyl-)oxy]kaur-16-en-19-oic acid (rebaudioside R1) and 13-[(2-O-6-deoxy-ß-d-glucopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl)oxy]kaur-16-en-19-oic acid, respectively. Chemical structures were determined by NMR experiments. HPLC analyses were also useful to differentiate different steviol-C13 sugar substituent patterns by elution position.


Asunto(s)
Diterpenos/aislamiento & purificación , Glicósidos/aislamiento & purificación , Stevia/química , Diterpenos/química , Diterpenos de Tipo Kaurano , Glicósidos/química , Estructura Molecular , Saponinas/análisis , Triterpenos/análisis
16.
J Nat Prod ; 79(5): 1468-72, 2016 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-27119206

RESUMEN

Two new diterpene glycosides have been isolated from a commercial extract of the leaves of Stevia rebaudiana. Compound 1 was shown to be 13-[(2-O-ß-d-glucopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-xylopyranosyl)oxy]ent-kaur-16-en-19-oic acid ß-d-glucopyranosyl ester (rebaudioside R), while compound 2 was determined to be 13-[(2-O-α-d-glucopyranosyl-ß-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid 2-O-α-l-rhamnopyranosyl-ß-d-glucopyranosyl ester (rebaudioside S). Six additional known compounds were identified, dulcoside B, 13-[(2-O-ß-d-xylopyranosyl-ß-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid ß-d-glucopyranosyl ester, eugenol diglucoside, rebaudioside G, 13-[(2-O-6-deoxy-ß-d-glucopyranosyl-3-O-ß-d-glucopyranosyl-ß-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid ß-d-glucopyranosyl ester, and rebaudioside D (3), respectively. The structures of 1 and 2 were determined based on comprehensive 1D and 2D NMR (COSY, HSQC, and HMBC) studies. A high-quality crystal of compound 3 allowed confirmation of its structure by X-ray diffraction.


Asunto(s)
Diterpenos de Tipo Kaurano/aislamiento & purificación , Glicósidos/aislamiento & purificación , Stevia/química , Diterpenos/química , Diterpenos/aislamiento & purificación , Diterpenos de Tipo Kaurano/química , Glicósidos/química , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Hojas de la Planta/química , Estereoisomerismo
17.
Parasitol Res ; 113(8): 2925-32, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24906989

RESUMEN

The search for new therapeutic agents from natural sources has been a constant for the treatment of diseases such as leishmaniasis. Herein, in vitro and in vivo pharmacological activities of pure major phenolic constituents (caffeic acid, chlorogenic acid, ferulic acid, quercetin, and rosmarinic acid) from Pluchea carolinensis against Leishmania amazonensis are presented. Pure compounds showed inhibitory activity against promastigotes (IC50 = 0.2-0.9 µg/mL) and intracellular amastigotes (IC50 = 1.3-2.9 µg/mL). Four of them were selected after testing against macrophages of BALB/c mice: caffeic acid, ferulic acid, quercetin, and rosmarinic acid, with selective indices of 11, 17, 10, and 20, respectively. Ferulic acid, rosmarinic acid, and caffeic acid controlled lesion size development and parasite burden in footpads from BALB/c experimentally infected mice, after five injections of compounds by intralesional route at 30 mg/kg every 4 days. Pure compounds from P. carolinensis demonstrated antileishmanial properties.


Asunto(s)
Antiprotozoarios/farmacología , Asteraceae/química , Leishmania mexicana/efectos de los fármacos , Leishmaniasis/tratamiento farmacológico , Animales , Ácidos Cafeicos/farmacología , Células Cultivadas , Cinamatos/farmacología , Ácidos Cumáricos/farmacología , Depsidos/farmacología , Femenino , Macrófagos/parasitología , Ratones , Ratones Endogámicos BALB C , Quercetina/análogos & derivados , Quercetina/farmacología , Ácido Rosmarínico
18.
Asian Pac J Trop Med ; 4(10): 836-40, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22014743

RESUMEN

OBJECTIVE: To evaluate the antileishmanial activity of different extracts from three Cuban Pluchea species. METHODS: In in vitro assays the IC(50) was calculated in the promastigotes and amastigotes forms as cytotoxicity in murine macrophages. In leishmaniasis cutanea experiment, mortality, weight loss, lesion size and burden parasite were measured. RESULTS: Extracts evaluated showed inhibitive effect on growing of promastigote form; however, active extracts caused a high toxicity. Ethanol and n-hexane extracts demonstrated specific antileishmanial activity. Ethanol and n-hexane extracts from Pluchea carolinensis (P. carolinensis) caused similar inhibition against amastigote form. The intraperitoneal administration of the ethanol extract of P. carolinensis at 100 mg/kg prevented lesion development compared with control groups. CONCLUSIONS: The antileishmanial experiment suggests that ethanol extracts from P. carolinensis is the most promising. Further studies are still needed to evaluate the potential of this plant as a source of new antileishmanial agents.


Asunto(s)
Asteraceae/química , Leishmania/efectos de los fármacos , Fitoterapia , Extractos Vegetales/farmacología , Hojas de la Planta/química , Animales , Modelos Animales de Enfermedad , Etanol , Femenino , Hexanos , Concentración 50 Inhibidora , Ratones , Ratones Endogámicos BALB C , Solventes , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA