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1.
J Dairy Sci ; 103(1): 72-86, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31677836

RESUMO

The aim of this study was to characterize minor lipids in methanol fraction extracted from raw camel milk after loading it on a water-preconditioned short C18 open column and fractionating with a gradient of methanol/water. The C18 column showed high fractionation efficiency of minor lipids, such as glycosphingolipids, lipopolysaccharides, or oligosaccharides, when compared with other constituents, in particular polysaccharides, proteins, and free fatty acids. Liquid chromatography electrospray ionization tandem mass spectrometry in negative ion mode was used to identify 21 new glycosphingolipids, lipopolysaccharides, and oligosaccharides. Electrospray ionization tandem mass spectrometry was qualified to provide relevant data for recognizing the molecular mass, glycosylation sequences, and structure of saccharide moieties for the revealed compounds. The sequence of combinations of one selected lipopolysaccharide, which was considered the backbone of the remaining lipopolysaccharides, was confirmed in a density functional theory study. The obtained results showed that the tested fraction is a rich source of glycosphingolipids, lipopolysaccharides, and oligosaccharides with antioxidant activity.


Assuntos
Camelus , Lipídeos/farmacologia , Leite/química , Oligossacarídeos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray/veterinária , Animais , Humanos , Lipídeos/química , Oligossacarídeos/química , Plasma , Espectrometria de Massas por Ionização por Electrospray/métodos
2.
Int J Mol Sci ; 18(3)2017 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-28257091

RESUMO

Phoenix dacylifera is an ancient palm species rich in (poly)phenols. These phenolic compounds were tentatively identified by using liquid chromatography coupled with ion spray mass spectrometry in tandem mode (LC/MS/MS) with negative ion detection. Negative identification of the compounds was based on their retention times and mass spectra in full scan mode (MS), and in different MS/MS modes. For the first time, complete hypothesis, and routs for both p-coumaroylshikimic acids (CoSA) and caffeoylshikimic acids (CSA) were suggested and confirmed by Density Fonctional Theory (DFT) study. Notably, of the 53 compounds characterized, 19 hydroxycinnamates derivatives were tentativelycharacterized in male flowers of date palm and 15 of them were recorded for the first time. In addition, five organic acids, six B-type proanthocyanidins, two anthocyanidin and 21 flavonoid derivatives have been tentatively characterized. Identification of B-type proanthocyanidins were based on the diagnostic ions resulting from heterocyclic ring fission (HRF) and retro-Diels-Alder (RDA) reaction of flavan-3-ol provided information on the hydroxylation pattern and the type of inter-flavan bond proanthocyanidins. The sequence of proanthocyanidins was detected through ions extracted from quinone methide (QM) cleavage of the inter-flavan bond.


Assuntos
Cromatografia Líquida/métodos , Phoeniceae/química , Polifenóis/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Ácidos Cafeicos/isolamento & purificação , Ácidos Cicloexanocarboxílicos/isolamento & purificação , Estrutura Molecular , Polifenóis/química , Polifenóis/isolamento & purificação , Ácido Chiquímico/isolamento & purificação
3.
Platelets ; 26(8): 788-94, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25901460

RESUMO

Phenolic compounds have different biological properties, including antioxidative activities, but they may also be prooxidants. The effect of phenolic fraction from roots of Alhagi maurorum on oxidative protein/lipid damages (determined by such parameters as levels of protein thiol groups and the concentration of thiobarbituric acid reactive species--TBARS) in human blood platelets and human plasma after treatment with hydrogen peroxide--H2O2 (which is the strong biologic oxidant and inflammatory mediator) was studied in vitro. We also studied the effect of A. maurorum extract on blood platelet activation corresponding to thrombin-induced arachidonic acid pathway. Moreover, the present work was designed to study the effect of A. maurorum extract on selected physiological function of blood platelets--adhesion of blood platelets to collagen in vitro. The action of phenolic fraction from A. maurorum was compared with the selected commercial phenolic extracts: extract from berries of Aronia melanocarpa (Aronox®), extract from bark of Yucca schidigera and monomeric polyphenol-resveratrol (3,4',5-trihydroxystilbene). Exposure of blood platelets or plasma to H2O2 resulted in a decrease of the level of thiol groups in proteins, and an increase of TBARS. In the presence of phenolic fraction from A. maurorum (0.5-50 µg/ml), a reduction of thiol groups oxidation together with the decrease of autoperoxidation of lipids and lipid peroxidation caused by H2O2 or thrombin was observed. The inhibitory, concentration-dependent effects of A. maurorum extract on adhesion of thrombin-activated platelets to collagen were also found. The phenolic fraction from A. maurorum acts as an antioxidant and can be useful as the natural factor protecting against diseases associated with oxidative stress. Tested fraction from A. maurorum has more effective antioxidative activity and antiplatelet properties than aronia extract or other commercial extract, however differences between their actions are not statistically significant.


Assuntos
Fabaceae/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Estilbenos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Fenóis/química , Extratos Vegetais/química , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Resveratrol
4.
Platelets ; 26(1): 87-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24512189

RESUMO

The present work was designed to study the effects of crude extracts from Tribulus pterocarpus, T. pentandrus and T. parvispinus on selected biological functions of human blood platelets in vitro. Platelet suspensions were pre-incubated with extracts from aerial parts of T. pterocarpus, T. pentandrus and T. parvispinus, at the final concentrations of 0.5, 5 and 50 µg/ml. Then, for platelet activation thrombin, was used. The effects of crude extracts from T. pterocarpus, T. pentandrus and T. parvispinus on adhesion of blood platelets to collagen were determined by method according to Tuszynski and Murphy. Arachidonic acid metabolism was measured by the level of thiobarbituric acid reactive substances (TBARS). In these studies we also compared the action of tested crude plant extracts with the effects of the polyphenolic fraction isolated from aerial parts of T. pterocarpus, which has antiplatelet and antioxidative properties. The performed assays demonstrated that the tested crude extract from T. pterocarpus and the phenolic fraction from T. pterocarpus might influence the platelet functions in vitro. The inhibitory, concentration-dependent effects of this tested extract and its phenolic fraction on adhesion of resting platelets and thrombin - stimulated platelets to collagen was found. We also observed that the crude extract from T. pterocarpus, like the polyphenolic fraction from T. pterocarpus reduced TBARS production in blood platelets. In the comparative studies, the tested crude extract from T. pterocarpus was not found to be more effective antiplatelet factor, than the polyphenolic fraction from this plant. The results obtained suggest that T. pterocarpus may be a promising source of natural compounds, valuable in the prevention of the enhanced activity of blood platelets in numerous cardiovascular diseases.


Assuntos
Ácidos Araquidônicos/metabolismo , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Extratos Vegetais/farmacologia , Adesividade Plaquetária/efeitos dos fármacos , Tribulus/química , Humanos , Extratos Vegetais/isolamento & purificação , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
5.
J Nat Prod ; 77(3): 657-62, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24527835

RESUMO

The aerial parts of Spergula fallax afforded four glycosides (1-4) based on two new triterpene aglycones (1a and 2a), along with the known hopane glycoside succulentoside A. Compound 1 was identified as belonging to the fernane class, unusual migrated hopane triterpenoids, mainly isolated from ferns and only rarely from higher plants. Compounds 2-4 were assigned as gammacerane glycosides, having as aglycone a hydroxylated derivative of tetrahymanol. The structures of the isolated compounds 1-4 and their aglycones 1a and 2a obtained by acid hydrolysis were elucidated by spectroscopic data interpretation. The growth inhibitory activity of the isolated compounds and their aglycones was evaluated against the HeLa and DLD-1 cancer cell lines.


Assuntos
Caryophyllaceae/química , Gleiquênias/química , Glicosídeos/isolamento & purificação , Triterpenos/isolamento & purificação , Ensaios de Seleção de Medicamentos Antitumorais , Egito , Glicosídeos/química , Glicosídeos/farmacologia , Células HeLa , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Triterpenos/química , Triterpenos/classificação , Triterpenos/farmacologia
6.
Platelets ; 25(1): 75-80, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23560434

RESUMO

The oxidative/nitrative stress induced by different factors plays an important role in the pathogenesis of various disorders, including cardiovascular diseases and cancer. Proanthocyanidins have antioxidative properties and may protect biomolecules (lipids, DNA, and proteins) exposed to reactive oxygen and nitrogen species, including peroxynitrite (ONOO(-)). The effects of proanthocyanidin fraction from Medemia argun nuts on oxidative/nitrative protein damages (determined by such parameters as level of thiol groups, carbonyl groups, and nitrotyrosine residues) and on the amount of glutathione (as an important component of redox status; using HPLC) in human blood platelets and plasma after treatment with peroxynitrite were studied in vitro. The preincubation of blood platelets and plasma with proanthocyanidin fraction from M. argun nuts (0.5-50 µg/ml) reduced the formation of 3-nitrotyrosine, diminished oxidation of thiol groups, and decreased the level of carbonyl groups in proteins caused by 100 µM peroxynitrite. An action of tested plant fraction and ONOO(-) evoked a significant increase of GSH in platelets and plasma in comparison with platelets and plasma treated with ONOO(-) only. The proanthocyanidin fraction from M. argun nuts can be useful as a protecting factor against oxidative/nitrative stress associated with different diseases (cancer, cardiovascular, and neurodegenerative diseases) and proanthocyanidins of M. argun nuts may be promising antioxidants.


Assuntos
Plaquetas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proantocianidinas/farmacologia , Adulto , Arecaceae/química , Humanos , Masculino , Nozes/química , Adulto Jovem
7.
Platelets ; 24(2): 156-61, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22463068

RESUMO

The antiplatelet and antioxidative activity of polyphenolic fraction isolated from aerial parts of Tribulus pterocarpus in blood platelets stimulated by thrombin was studied. Thrombin as a strong physiological agonist induces the enzymatic peroxidation of endogenous arachidonic acid, the formation of different reactive oxygen species, including superoxide anion radicals ([Formula: see text](·)) and the platelet aggregation. Therefore, the aim of our study was to assess if the polyphenolic fraction from aerial parts of T. pterocarpus may change the biological properties of blood platelets activated by thrombin. We used cytochrome c reduction method to test the ability of this fraction to change [Formula: see text](·) generation in platelets. Arachidonic acid metabolism was measured by the level of thiobarbituric acid reactive substances (TBARS) and by the production of 8-epi-prostaglandin (8-EPI) F(2). Moreover, we determined the effects of the fraction on blood platelet aggregation induced by thrombin. We observed that the polyphenolic fraction from T. pterocarpus reduced [Formula: see text](·), 8-EPI and TBARS production in these cells. The ability of the fraction to decrease the [Formula: see text](·) generation in blood platelets supports the importance of free radicals in platelet functions, including aggregation process. This study may suggest that the tested plant fraction might be a good candidate for protecting blood platelets against changes of their biological functions, which may be associated with the pathogenesis of different cardiovascular disorders.


Assuntos
Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Componentes Aéreos da Planta/química , Inibidores da Agregação Plaquetária/farmacologia , Polifenóis/farmacologia , Tribulus/química , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Trombina/farmacologia
8.
Nat Prod Res ; 37(1): 136-140, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34498958

RESUMO

The present study has tentatively elucidated the structure of two acylated polyoxypregnane glycosides from Caralluma quadrangula (Forssk.) N.E.Br. (CQ). The analyses were performed using an electrospray-ionization quadrupole time-of-flight (ESI-Q-TOF) mass spectrometer in positive ionization modes to explore fragmentation pathways. The used ionization mode provided consistent and/or complementary information for most of the pregnane glycosides, their fragmentation sequences, and their aglycones. Presumably, this is due to higher efficiency, sensitivity, and better selectivity of the mass spectrometry-based method. The present experimental and theoretical report deals with the characteristic fragmentation behaviors of two acylated polyoxypregnane glycosides CQ1 and CQ2 from the aerial parts of C. quadrangular. A DFT Study was performed to elucidate the position of ikemoyl, and benzoyl residues in compounds CQ1 and CQ2, respectively.


Assuntos
Apocynaceae , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Glicosídeos/química , Cromatografia Líquida de Alta Pressão/métodos
9.
Phytochem Anal ; 23(6): 613-21, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22517607

RESUMO

INTRODUCTION: Tribulus is a well-known pharmaceutical herb that has been used for a long time in the traditional Chinese and Indian systems of medicine for the treatment of various diseases. It has been found that the genus Tribulus is rich in biologically active furostane-, cholestane- and spirostane-type steroidal saponins. OBJECTIVE: To develop a rapid, sensitive and accurate method based on liquid-phase extraction followed by high-performance liquid chromatography and electrospray ionisation mass spectrometry (HPLC-ESI-MS) to identify different saponins in three species of the genus Tribulus, and to quantify the compounds that are already known. METHODOLOGY: After extraction from the species studied, the extracts were subjected to HPLC analyses with an XTerra® MS C(18) -column and a binary mobile phase consisting of 0.05% formic acid in water and acetonitrile, and with an ESI-MS detection in the negative ion mode. Data were acquired and processed using the Xcalibur 1.3 software. RESULTS: The results exhibited that the profiles of native steroidal glycosides of both T. pentandrus and T. megistopterus subsp. pterocarpus were very similar to each other, but that of T. parvispinus was remarkably different. The fragmentation patterns provided evidence that the saponins possess spirostane-, cholestane- and furostane-type aglycones. Quantitative analyses suggested that these species are a rich source of steroidal saponins. CONCLUSION: HPLC-ESI-MS/MS allowed identification of the key compounds without preparative isolation of the components from the crude extract of Tribulus species.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Saponinas/análise , Saponinas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Tribulus/química , Calibragem , Colestanos/análise , Extração Líquido-Líquido/métodos , Componentes Aéreos da Planta/química , Extratos Vegetais/análise , Extratos Vegetais/química , Sensibilidade e Especificidade
10.
Biomed Pharmacother ; 150: 112954, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35447547

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Caralluma quadrangula (Forssk.) N.E.Br. (Syns: = Stapelia quadrangula Forssk. = Monolluma quadrangula Forssk.) is an indigenous member of the genus Caralluma and it is a rather common species on rocky hillsides in the southwestern part of Saudi Arabia. Several members of this genus have found medicinal uses in the treatment of rheumatism, diabetes, leprosy and as antiseptics and disinfectants. All parts are edible but rather more bitter and can cause diarrhea. AIM OF THE STUDY: The present report was tentatively elucidated the structure of acylated and non-acylated polyoxypregnane glycosides from Caralluma quadrangula. MATERIALS AND METHODS: The analyses were performed using an electrospray-ionization quadrupole time-of-flight (ESI-Q-TOF) mass spectrometer in both positive and negative ionization modes to explore fragmentation pathways. The antioxidant and prooxidant properties of the different mobility portions of human plasma were evaluated in vitro using thiobarbituric acid reactive substance assay (TBARS). RESULTS: The analyses showed sixty-five characteristic ion peaks which could be more efficient to assignment the aglycones and fragmentation sequences of sugar moieties. The used ionization modes provided consistent and/or complementary information for most of the pregnane glycosides, their fragmentation sequences, and their aglycones. A DFT Study was performed to elucidate the neutral loss of H2O molecules sequences from aglycones and the esterification linkage. CONCLUSIONS: This report could be useful to reduce material consuming and time in phytochemistry analysis of the different medicinal plants. The two portions significantly depleted TBARS were subjected to autoperoxidation assay in the presence of hydrogen peroxide.


Assuntos
Antioxidantes , Apocynaceae , Antioxidantes/farmacologia , Apocynaceae/química , Cromatografia Líquida de Alta Pressão , Glicosídeos/farmacologia , Humanos , Saponinas , Espectrometria de Massas por Ionização por Electrospray , Substâncias Reativas com Ácido Tiobarbitúrico
11.
Int. j. morphol ; 42(2)abr. 2024.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1558145

RESUMO

SUMMARY: This study evaluated the phytochemical screening, antioxidant capacity, and in vitro anticancer activities of four plants namely, Gypsophila capillaris, Anabasis lachnantha, Haloxylon salicornicum, and Horwoodia dicksoniae which belong to four different families: Caryophyllaceae, Amaranthaceae, Chenopodiaceae, Brassicaceae, respectively. The total phenolics, anthocyanins, saponins, total antioxidant capacity (TAC), and DPPH assays were determined by spectrophotometer. In vitro anticancer activity was assessed using two human cancer cell lines; hepatocellular carcinoma (HepG-2) and breast adenocarcinoma (MCF-7) to estimate the inhibition concentration 50 % (IC50). The results showed that H. dicksoniae has the highest concentrations of phenolics and saponins, while H. salicornicum has the highest DPPH. The highest concentration of TAC was found in G. capillaries. Among the tested extracts, G. capillaries and H. salicornicum have the potential activity against MCF-7 and HepG-2 cell lines in vitro. The content of polyphenols in G. capillaries was profiled by high-performance liquid chromatography (HPLC). The highest concentration among the phenolic compounds was chlorogenic (60.8 µg/ml) while the highest concentration among the flavonoid compounds was hesperidin (1444.92 µg/ml). In summary, G. capillaries and H. salicornicum extracts have potent anticancer activity against HepG-2 and MCF-7 cell lines.


Este estudio evaluó la detección fitoquímica, la capacidad antioxidante y las actividades anticancerígenas in vitro de cuatro plantas, Gypsophila capillaris, Anabasis lachnantha, Haloxylon salicornicum y Horwoodia dicksoniae, que pertenecen a cuatro familias diferentes: Caryophyllaceae, Amaranthaceae, Chenopodiaceae y Brassicaceae, respectivamente. Los ensayos de fenólicos totales, antocianinas, saponinas, capacidad antioxidante total (TAC) y DPPH se determinaron mediante espectrofotómetro. La actividad anticancerígena in vitro se evaluó utilizando dos líneas celulares de cáncer humano; carcinoma hepatocelular (HepG-2) y adenocarcinoma de mama (MCF- 7) para estimar la concentración de inhibición del 50 % (IC50). Los resultados indicaron que H. dicksoniae tiene las concentraciones más altas de fenólicos y saponinas, mientras que H. salicornicum tiene el DPPH más alto. La mayor concentración de TAC se encontró en G. capillaries. Entre los extractos probados, G. capillaries y H. salicornicum tienen actividad potencial contra líneas celulares MCF-7 y HepG-2 in vitro. El contenido de polifenoles en G. capillaries se perfiló mediante cromatografía líquida de alta resolución (HPLC). La concentración más alta entre los compuestos fenólicos fue clorogénica (60,8 µg/ml), mientras que la concentración más alta entre los compuestos flavonoides fue la hesperidina (1444,92 µg/ml). En resumen, los extractos de Gypsophila capillaris y H. salicornicum tienen una potente actividad anticancerígena contra las líneas celulares HepG-2 y MCF-7.

12.
Nat Prod Res ; 31(17): 2024-2031, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28049352

RESUMO

A fingerprint of steroid saponins, the major constituent in 80% methanolic fraction from the male flowers of Phoenix dactylifera has been established. Under ESI-MS/MS conditions, the fragmentation patterns of [M - H]- ions exclusively displayed signals corresponding to the cleavage of the glycosidic bonds, thus allowing a rapid identification of 21 steroidal saponins. Moreover, two unique among them conjugated with histidine were detected by LC-ESI (-)-MS and DFT and were given tentative names of 3-o-histidine-26-o-hexosyl-dioscin and 3-o-histidine-26-o-dihexosyl-hydroxydioscin. Their steroidal saponins exhibited a significant improvement of the sperm cells count, motility and viability in male rats. These effects could be attributed to enhancing the levels of sex hormones.


Assuntos
Phoeniceae/química , Saponinas/química , Saponinas/farmacologia , Espermatogênese/efeitos dos fármacos , Animais , Cromatografia Líquida , Avaliação Pré-Clínica de Medicamentos/métodos , Flores/química , Masculino , Ratos Wistar , Saponinas/análise , Espectrometria de Massas por Ionização por Electrospray , Contagem de Espermatozoides , Espermatozoides/efeitos dos fármacos , Esteroides/química , Esteroides/farmacologia , Espectrometria de Massas em Tandem
13.
Nat Prod Commun ; 11(3): 279-82, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27169174

RESUMO

Medemia argun is a mysterious and little known monotypic fan palm from the Nubian Desert Oases of southern Egypt and northern Sudan. Its fruits have been found in the tombs from the 5th Dynasty (ca. 2500 BC) to Roman times (6-7th century AD), including the celebrated tomb of Tutankhamun. In ancient Egypt, the fruits of this palm were widely distributed and were highly valued, as confirmed by their frequent occurrence in offerings in the tombs. In order to elucidate the chemical composition of the phenolic fraction, phytochemical investigation of the BuOH extract of fruits was carried out to afford eight compounds (1-8), among which was the new 2,4-dihydroxy-6-methylacetophenone 2-0-ß-D-glucopyranoside (1). With the aim to investigate if the high shelf life of M argun fruits could be related to the occurrence of antioxidant principles that were able to prevent oxidative reactions, the evaluation was carried out of the in vitro antioxidant activity by Trolox equivalent antioxidant capacity (TEAC) assay of the extract and isolated compounds.


Assuntos
Antioxidantes/farmacologia , Frutas/química , Fenóis/farmacologia , Plantas Comestíveis/química , Plantas Medicinais/química , Antioxidantes/química , Egito , Estrutura Molecular , Fenóis/química
14.
Food Res Int ; 85: 282-290, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29544846

RESUMO

Samh flour (Mesembryanthemum forsskalei) is a foodstuff with high protein content, which can be used as a replacement for wheat flour. It is often consumed by Bedouin tribes of northern Saudi Arabia. Very little is known about bioactive molecules present in samh flour, therefore we analyzed its extracts to evaluate the contents of secondary metabolites. A total of 43 secondary metabolites present in 60% MeOH extract of samh flour were tentatively identified using LC-ESI-MS/MS. These compounds represented five major categories: glucosinolates, sinapic acid and sinapoylglycosides, acylated flavonoids, flavonoids, and amide derivatives. Their effect on oxidative damage of proteins and lipids was determined in vitro by assessing levels of protein thiol groups and concentrations of thiobarbituric acid reactive species (TBARS) in human plasma. Obtained results indicated that samh flour is a rich source of compounds with antioxidant activity.

15.
Steroids ; 70(9): 594-603, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15946718

RESUMO

Seven new 15-keto pregnane glycosides, namely Stemmosides E--K, were isolated from Solenostemma argel. Stemmosides E--J are characterized by the occurrence of an uncommon 14 beta proton configuration while stemmosides E and F possess in addition a rare enolic function in C-16. On the other hand, stemmosides G-J display an unusual C-17 alpha side chain. Their structures were established by ESI-MS and NMR experiments. Moreover, the effect of these compounds on the VEGF-induced in Kaposi's sarcoma cell proliferation was tested. Results indicated that all the compounds reduced the cell proliferation in a dose dependent manner.


Assuntos
Apocynaceae/química , Proliferação de Células/efeitos dos fármacos , Glicosídeos/química , Pregnanos/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Extratos Vegetais/química , Pregnanos/isolamento & purificação , Pregnanos/farmacologia , Espectrometria de Massas por Ionização por Electrospray , Fator A de Crescimento do Endotélio Vascular/farmacologia
16.
Phytochemistry ; 65(21): 2935-45, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15501264

RESUMO

Seven new steroidal glycosides named pentandrosides A(1)-G(7) were isolated from the EtOH extract of the aerial parts of Tribulus pentandrus. Pentandrosides A(1)-E(5) possess cholestane aglycones, pentandroside F(6) a furostan-type aglycone and pentandroside G(7) an unusual acyloxypregnane aglycone probably derived from the degradation of a furostan skeleton. Structure elucidation of 1-7 was accomplished through the extensive use of 1D- and 2D NMR experiments including 1H-1H (DQF-COSY, 1D-TOCSY) and 1H-13C (HSQC, HMBC) spectroscopy along with ESIMS and HRESIMS.


Assuntos
Componentes Aéreos da Planta/química , Saponinas/isolamento & purificação , Tribulus/química , Cromatografia Gasosa , Espectroscopia de Ressonância Magnética , Estrutura Molecular
17.
Phytochemistry ; 65(7): 975-80, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15081304

RESUMO

Three new polyhydroxypregnane glycosides named alpinoside A [kidjolanin 3-O-beta-d-glucopyranosyl-(1-->4)-beta-d-glucopyranosyl-(1-->4)-beta-d-thevetopyranosyl-(1-->4)-beta-d-cymaropyranosyl-(1-->4)-beta-d-cymaropyranoside], alpinoside B [kidjolanin 3-O-beta-d-glucopyranosyl-(1-->4)-beta-d-thevetopyranosyl-(1-->4)-beta-d-cymaropyranosyl-(1-->4)-beta-d-cymaropyranoside], and alpinoside C [kidjolanin 3-O-beta-d-glucopyranosyl-(1-->4)-beta-d-glucopyranosyl-(1-->4)-beta-d-oleandropyranosyl-(1-->4)-beta-d-cymaropyranosyl-(1-->4)-beta-d-cymaropyranoside] were isolated from the leaves of Oxystelma esculentum var. alpini. The structure elucidation was accomplished by extensive spectroscopic analysis and acid-catalyzed hydrolysis.


Assuntos
Apocynaceae/química , Glicosídeos/química , Pregnanos/química , Configuração de Carboidratos , Sequência de Carboidratos , Cromatografia Gasosa , Glicosídeos/isolamento & purificação , Hidrólise , Hidroxilação , Dados de Sequência Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Componentes Aéreos da Planta/química , Pregnanos/isolamento & purificação
18.
J Mass Spectrom ; 49(4): 306-15, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24719346

RESUMO

Medemia argun is an ancient palm rich in proanthocyanidins (PACs). These polyphenolic compounds are widely distributed in plants and are an integral part of the human diet. A sensitive high-performance liquid chromatography and electrospray ionization mass spectrometry (HPLC-ESI-MS) method in the negative ion mode for sequencing these ubiquitous and highly beneficial antioxidants is described in order to profile different PACs in M. argun nuts. The analytical protocol based on tandem mass spectrometry was used to sequence dimers, trimers, tetramers and pentamers with different A-type, B-type and A/B-type linkages. Diagnostic ions resulting from heterocyclic ring fission and retro-Diels-Alder reaction of flavan-3-ol provided information on the hydroxylation pattern and the type of interflavan bond. The sequences were discovered through ions derived from quinone methide cleavage of the interflavan bond. The identification of PACs linkages through LC-MS(n) eliminates a number of tedious separation steps. The method was successfully applied to give a view of PAC profile in M. argun nuts. M. argun nuts contained 636.88 mg/g PACs (as equivalent of (þ)-catechin). The data obtained in our research show that M. argun is a rich source of hydrolyzable PACs.


Assuntos
Arecaceae/química , Nozes/química , Proantocianidinas/análise , Proantocianidinas/química , Cromatografia Líquida , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
19.
Food Chem Toxicol ; 56: 266-71, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23376508

RESUMO

The phenolic fraction and the crude extract from Tribulus pterocarpus have different biological activity, including antiplatelet-antiadhesive properties. Since it is demonstrated that hyperhomocysteinemia may act as stimulator of blood platelet activation (platelet adhesion, aggregation, and secretion), but various antiplatelet compounds are able to reduce hyperactivation of blood platelets induced by hyperhomocysteinemia. The aim of our present experiments was to investigate in vitro one of the step in platelet activation process - platelet adhesion to collagen induced by the model of severe hyperhomocyateinemia in the presence of the phenolic fraction and the crude extract from T. pterocarpus. Severe hyperhomocysteinemia was induced by reduced form of Hcy in the concentrations 0.1mM and 1mM, or using HTL in the concentrations 0.1, 0.5 and 1 µM. Adhesion of blood platelets to collagen was determined according to Tuszynski and Murphy. We observed that the phenolic fraction and the crude extract from T. pterocarpus have the inhibitory effect on platelet adhesion during severe hyperhomocysteinemia. The action of tested phenolic and crude extract was concentration-dependent, but the phenolic fraction was stronger antiadhesive action than the crude extract. We suggest that T. pterocarpus may be good source of antiplatelet compounds during hyperhomocysteinemia.


Assuntos
Plaquetas/efeitos dos fármacos , Hiper-Homocisteinemia/tratamento farmacológico , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Adesividade Plaquetária/efeitos dos fármacos , Tribulus/química , Adulto , Humanos , Agregação Plaquetária/efeitos dos fármacos , Adulto Jovem
20.
Nat Prod Commun ; 7(5): 633-6, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22799095

RESUMO

The fruits of the edible and medicinal Egyptian palm, Medemia argun, were collected from Aswan in Egypt and the essential oil (EO) from fruits and headspace (HS) of the seeds and fleshy mesocarps were analyzed by GC and GC-MS. Results obtained by GC-MS analysis indicated a high variability in the oil and in the headspace from seeds and mesocarps. Sesquiterpene derivatives were the main group of volatiles in the EO from fruits and in the HS from seeds (45.0 and 64.0%, respectively), while oxygenated hydrocarbon derivatives were the main constituents in the HS obtained from fleshy mesocarps (96.5%). The different chemical composition of the headspace obtained from the seeds and mesocarps of M. argun can be correlated with the different roles that the different constituents play in the prevention of dehydration of the fruits in the desert region from where the plant was collected.


Assuntos
Arecaceae/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Óleos Voláteis/análise , Egito , Frutas/química
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