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1.
The different interactions of p-hydroxybenzoic acid (1), a simple biophenol (BP) found in olives and their food products, and its substitute analogues, benzoic (2), anisic (3), and toluic (4) acids, with a model membrane represented by dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles (MLV) was studied by differential scanning calorimetry (DSC). The influence of their different lipophilic character on transfer and absorption processes through an aqueous medium into a lipid bilayer was also investigated. DSC experiments allowed monitoring of the interaction of BP with biomembranes by considering the effects exerted on the thermotropic behavior of DMPC multilamellar and unilamellar vesicles at different pHs (4 and 7.4). The examined compounds affect the transition temperature (T(m)) of phospholipid vesicles, causing a shift toward lower values, which is modulated by the molecular fraction entering into the lipid bilayer, as well as by their molecular interaction with the lipids. Kinetic calorimetric measurements were performed on suspensions of blank liposomes immediately after being added to fixed weighed amounts of powdered compounds and after increasing incubation periods at 37 degrees C. T(m) shifts, due to molecular dissolution and transfer of the compounds into the membrane surface occurring during the incubation time, were compared with those determined by a fixed molar fraction of free compounds directly dispersed in the membrane. The results show that the kinetic process, involved in molecular release, transfer through aqueous medium, and uptake by the model membrane surface, is influenced by lipophilicity as well as by pH, acting on the acid solubility and membrane disorder, allowing us to gather useful information on the BP intake process of olive derived foodstuffs.  相似文献   

2.
The present study investigated the mechanism of the synergistic antioxidant activity of alpha-tocopherol with resveratrol (3,5,4'-trihydroxy-trans-stilbene, 3,5,4'-THS) and its synthetic analogues, that is, 3,4-dihydroxy-trans-stilbene (3,4-DHS), 4,4'-dihydroxy-trans-stilbene (4,4'-DHS), 4-hydroxy-trans-stilbene (4-HS), and 3,5-dihydroxy-trans-stilbene (3,5-DHS). The reaction kinetics of alpha-tocopheroxyl radical with resveratrol and its analogues were studied in sodium dodecyl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB) micelles using the stopped-flow electron paramagnetic resonance (EPR) technique. It was found that resveratrol and its analogues could regenerate alpha-tocopherol with rate constants (k(REG)) in the order of 3,4-DHS > 4,4'-DHS > resveratrol > or = 4-HS > or = 3,5-DHS in SDS and CTAB micelles. It was found that the analogues bearing o-dihydroxyl groups (3,4-DHS) and p-dihydroxyl groups (4,4'-HS) exhibited remarkably higher alpha-tocopherol-regenerating activity than those bearing no such groups (resveratrol, 4-HS, and 3,5-DHS). In addition, the alpha-tocopherol-regenerating activity of resveratrol and its analogues was correlated with their electrochemical behaviors, suggesting that electron transfer might play a critical role during the regeneration reaction.  相似文献   

3.
The effect exerted by two structurally similar limonoids possessing antifeedant and anticancer activity, limonin and nomilin, on the thermotropic behavior of model membranes constituted by dimyristoylphosphatidylcholine (DMPC) vesicles was studied by differential scanning calorimetry. Attention was directed to evaluate modifications in phytochemical-lipid interaction induced by compound structure and lipophilicity and to evidence their different membrane penetration. The two examined compounds, when dispersed in liposomes during their preparation, were found to exert a very different action on the L(beta)-L(alpha) gel-to-liquid crystal phase transition of DMPC multilamellar vesicles. Nomilin caused a detectable effect on the transition temperature (T(m)), shifting it toward lower values with a concomitant small decrease of the associated enthalpy (DeltaH) changes, while limonin was not able to modify the lipid vesicles thermotropic behavior. Modifications induced by nomilin were a function of phytochemical concentration, while the different behavior of limonin can be due to the different polarity induced by the presence of the single A ring in nomilin that possesses an acetyl group versus the A,A' ring system of limonin. Solid limonoids and aqueous dispersions of multilamellar (MLVs) or unilamellar vesicles (LUVs) (limonoids molar fraction 0. 045, 0.12, and 0.18) were left in touch for long incubation times at temperatures higher than T(m) to detect their spontaneous transfer through the medium. By following this procedure, no interaction was detected for limonin with lipid vesicles. The rate of transfer and interaction of nomilin was a function of the kind of vesicle species (faster for LUV, slower for MLV). The interaction, monitored by compound transfer from the solid phytochemical to the lipidic species after several periods of incubation, was on the same order as that detected by preparation carried out in organic solvent. The obtained results can be explained in terms of compound hydrophobicity, and a relation between compound structure and membrane interaction can be suggested. This allows the membrane interaction with nomilin, but the low water solubility of limonin hinders or totally blocks its transfer through the aqueous medium.  相似文献   

4.
Previous studies on the transport and absorption of resveratrol (3,5,4-O-trihydroxystilbene) were done using the pure compound. In this study, the absorption of resveratrol in digested peanut micellar from boiled and roasted peanuts was investigated using a human intestinal Caco-2 cell monolayer. The amount transported and rate of transport of both resveratrol glycosides and its hydrolytic product were quantified by a reverse-phase high-performance liquid chromatography method with mass spectrometric detection. Four peaks were identified in the digested peanut micellar of both boiled and roasted peanuts: two resveratrol glycosides, one resveratrol diglycoside, and possibly an acylated resveratrol glycoside. Resveratrol from roasted peanut micellar had a higher transport rate than those from the boiled peanut. This implies that resveratrol from roasted peanut is better absorbed than from boiled peanut. Also, the rate of transport and amount of resveratrol transported were higher for the hydrolytic product than the nonhydrolyzed glycosides. This has strong implications for in vivo absorption as the enzymatic activity of gut microflora could enhance the bioavailability of β-glycosides of dietary polyphenols.  相似文献   

5.
The roots of two varieties of Polygonum cuspidatum (Hu Zhang and Mexican Bamboo) were analyzed for resveratrol and analogues. The roots of each variety were dried and ground into a powder. The powdered roots were then extracted with methanol and ethyl acetate. The ethyl acetate fraction of the Mexican Bamboo was then subjected to fractionation and purification using silica gel column chromatography and semipreparative HPLC. In addition to resveratrol (3,5,4'-trihydroxystilbene), three stilbene glucosides were identified by (1)H NMR, (13)C NMR, and MS. The stilbene glucosides were shown to be a piceatannol glucoside (3,5,3', 4'-tetrahydroxystilbene 4'-O-beta-D-glucopyranoside), resveratroloside (3,5,4'-trihydroxystilbene 4'-O-beta-D-glucopyranoside), and piceid (3,5,4'-trihydroxystilbene 3-O-beta-D-glucopyranoside). The levels of the piceatannol glucoside and piceid were twice as high in the Mexican Bamboo as compared to the Hu Zhang.  相似文献   

6.
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7.
The phytoalexin resveratrol (3,5,4'-trihydroxystilbene) in edible peanut (Arachis hypogaea L.) and pistachio (Pistacia vera L.) varieties grown in Turkey was analyzed by high-performance liquid chromatographic diode array and gas chromatography-mass spectrometric detection. trans-Resveratrol in six peanut varieties, five pistachio varieties, and four market samples ranged between 0.03 and 1.92 microg/g. The Cerezlik 5025 peanut (1.92 +/- 0.01 microg/g) and Ohadi pistachio genotype (1.67 +/- 0.01 microg/g) had significantly higher trans-resveratrol contents. Peanuts contained 0.03-1.92 microg/g (av = 0.84 microg/g) of trans-resveratrol, whereas pistachio contained 0.09-1.67 microg/g (av = 1.15 microg/g). With exposure to UV light for 1 min, trans-resveratrol concentrations of samples ranged from 0.02 to 1.47 microg/g and those of cis-resveratrol from 0.008 to 0.32 microg/g. The occurrence of resveratrol in peanut and pistachio was confirmed by total ion chromatograms (TIC) of bis[trimethylsilyl]trifluoroacetamide derivatives of resveratrol isomers and comparison of the mass spectral fragmentation data with those of a resveratrol standard. Formation of the cis-isomer in pistachios was higher than in peanuts.  相似文献   

8.
Grapes produce large amounts of polyphenols. Many of them accumulate in the skin, pulp, and seeds and are consequently found in wine. The health benefits of a moderate consumption of wine have been attributed at least in part to grape's polyphenols. Among them, resveratrol (3,5,4'-trihydroxystilbene) is a phytoalexin that stimulates plant cell defenses against infections and also plays protective roles in humans, where it delays cardiovascular alterations and exerts anticancer and anti-inflammatory effects. Despite numerous studies, the molecular mechanisms of resveratrol action are only partially understood. Given its pleiotropic effects, it was previously suggested that resveratrol protective properties may arise from its modulation of the expression of microRNAs. Therefore, this review will focus on the effects of resveratrol on microRNA populations in humans and human cell lines, especially emphasizing the microRNAs that have been implicated in resveratrol effects on inflammation, cancer, metabolism, and muscle differentiation.  相似文献   

9.
The effect of some polyphenols (resveratrol, catechin, epigallocatechin-3-gallate, and quercetin) and beverages (red wine and green tea) on the enzymatic activity of pepsin during the digestion of three different substrates (pork meat, insoluble azocasein, and denatured hemoglobin) has been investigated. The tested polyphenols and beverages increase the initial velocity of the reaction, and the activating effect is concentration dependent. The order of effectiveness of polyphenols in increasing the initial velocity of the reaction is resveratrol > or = quercetin > epigallocatechin-3-gallate > catechin. The kinetic data obtained with soluble denatured hemoglobin show that the K(m) for the substrate is not changed, whereas the V(max) of the reaction is increased. Pepsin activity follows a simple Michaelis-Menten kinetic suggesting that k(3) is increased by polyphenols. To the authors' knowledge, the present study is the first demonstration that some polyphenols and related beverages are able to enhance the enzymatic activity of pepsin.  相似文献   

10.
The roots of Rumex bucephalophorus, collected in Israel, were analyzed for trans-stilbenes. Two stilbene-O-glycosyl derivatives were identified, in addition to 3,5,4'-trihydroxystilbene (1) (resveratrol). The stilbene-O-glycosyl derivatives were 5,4'-dihydroxystilbene-3-O-beta-d-glucopyranoside (2) (piceid) and the new 5,4'-dihydroxystilbene-3-O-alpha-arabinopyranoside (3), which is being named rumexoid. The structure of rumexoid was elucidated by using spectroscopic data. The antioxidant capacities of stilbenoids 1-3 were determined and expressed as trolox equivalent antioxidant capacity (TEAC). TEAC value for trans-resveratrol was highest (2.7) and for rumexoid lowest (1.5). In vitro, trans-resveratrol and rumexoid demonstrated a potent inhibitory effect on alpha-glucosidase activity (IC50 < 0.1 and < 0.5 mM, respectively). The commercial antidiabetic agent acarbose was shown to inhibit only 35% of the enzyme activity at 0.5 mM. The addition of piceid to the reaction mixture did not inhibit alpha-glucosidase in vitro in the range of concentrations used. These findings extend the range of reported beneficial effects of stilbene derivatives, and demonstrate the multifaceted activities that dietary polyphenols may exert in the intestine, where their concentrations are highest in the body.  相似文献   

11.
The effect of the naturally occurring polyphenol resveratrol (3,5,4'-trihydroxy-trans-stilbene; RES) on growth, cell cycle, and cyclins A, E, and B1 expression was investigated in the human SK-Mel-28 melanoma cell line. In addition, the structurally related compounds 4-hydroxy-trans-stilbene (4HST), piceatannol (3,5,3',4'-tetrahydroxy-trans-stilbene (PICE), and 4-trans-stilbenemethanol (4STMe) were also assayed in order to investigate the requirements of stilbenes to exert activity against melanoma cells. Both RES and 4HST inhibited cell growth in a dose- and time-dependent manner and upregulated the expression of cyclins A, E, and B1 with subsequent irreversible arrest of melanoma cells in the S-phase, concomitant with a decrease in G0/G1 and G2/M phases. In addition, potent apoptosis-mediated cell death was detected with the annexin V assay whereas no apoptosis was observed by flow cytometry, which encourages the assay of different methodologies to evaluate the effect of polyphenols on cell lines. The effect of PICE was not evaluated because of its instability in the reaction medium. No effect on cell cycle and cyclins expression was observed when 4STMe was assayed, which supported the critical requirement of the 4'-hydroxystyryl moiety to exert the above effects. In addition, this structural requirement also influenced the cellular uptake of stilbenes. The presence of two extra hydroxyl groups in RES increased its cytotoxicity whereas it diminished its efficiency to inhibit cell growth, upregulate cyclins expression, and arrest cell cycle in the S-phase with respect to 4HST. The present study suggests that the antimelanoma properties of dietary stilbenes, such as grape RES, cannot be ruled out, taking into account previous studies concerning the relationship between plasma and tissue concentrations and pharmacological activity of RES in animal models.  相似文献   

12.
The iron dialyzability and uptake in relation to transit time through the stomach and small intestine was investigated using a dynamic in vitro gastrointestinal model in combination with Caco-2 cells. Three test meals were evaluated, consisting of lactic fermented vegetables with white (I) or whole meal bread (II) and of sourdough-fermented rye bread (III). Three transit times were tested (fast, medium, and slow transport). Iron dialyzability and absorption differed significantly between medium and slow transit time for meal I and between fast and medium transit time for meal III. For meal II, high in phytate, the iron dialyzability and absorption were low irrespective of transit time. The meals could be ranked with respect to iron dialyzability and uptake in the order I > III > II. Although the in vitro models used have limitations compared to in vivo experiments, the results suggest that an increased transit time may improve iron availability.  相似文献   

13.
Resveratrol (trans-3,5,4'-trihydroxystilbene) is a plant phytoalexin which has positive effects on human health. Stilbene synthase (STS) is a key enzyme involved in resveratrol biosynthesis. To construct a vector for STS expression in lettuce plant, a cDNA-encoding STS of Parthenocissus henryana was fused to the Cauliflower mosaic virus (CaMV) 35S promoter, and the bar gene was used as a selective marker gene. To increase the expression of STS, the expression cassette was flanked by MARs. In transgenic lettuce plants, an additional compound was identified as resveratrol by HPLC and ESI-MS. Quantitative analysis showed that the average content of resveratrol reached 56.40 +/- 5.52 microg/g leaf fresh weight, which was comparable to the amount in grape skin. Anticancer assay in HeLa cells revealed that apoptosis was induced by 200 microM of resveratrol extracted from transgenic lettuce.  相似文献   

14.
The peanut plant (Arachis hypogaea L.), when infected by a microbial pathogen, is capable of producing stilbene-derived compounds that are considered antifungal phytoalexins. In addition, the potential health benefits of other stilbenoids from peanuts, including resveratrol and pterostilbene, have been acknowledged by several investigators. Despite considerable progress in peanut research, relatively little is known about the biological activity of the stilbenoid phytoalexins. This study investigated the activities of some of these compounds in a broad spectrum of biological assays. Since peanut stilbenoids appear to play roles in plant defense mechanisms, they were evaluated for their effects on economically important plant pathogenic fungi of the genera Colletotrichum, Botrytis, Fusarium, and Phomopsis. We further investigated these peanut phytoalexins, together with some related natural and synthetic stilbenoids (a total of 24 compounds) in a panel of bioassays to determine their anti-inflammatory, cytotoxic, and antioxidant activities in mammalian cells. Several of these compounds were also evaluated as mammalian opioid receptor competitive antagonists. Assays for adult mosquito and larvae toxicity were also performed. The results of these studies reveal that peanut stilbenoids, as well as related natural and synthetic stilbene derivatives, display a diverse range of biological activities.  相似文献   

15.
In recent years an effort has been made to isolate and identify biologically active compounds that are included in the Mediterranean diet. The existence of naturally occurring acetylated phenolics, as well as studies with synthetic ones, provide evidence that acetyl groups could be correlated with their biological activity. Platelet activating factor (PAF) is implicated in atherosclerosis, whereas its inhibitors seem to play a protective role against cardiovascular disease. The aim of this study was to examine the biological activity of resveratrol and tyrosol and their acetylated derivatives as inhibitors of PAF-induced washed rabbit platelet aggregation. Acetylation of resveratrol and tyrosol was performed, and separation was achieved by HPLC. Acetylated derivatives were identified by negative mass spectrometry. The data showed that tyrosol and its monoacetylated derivatives act as PAF inhibitors, whereas diacetylated derivatives induce platelet aggregation. Resveratrol and its mono- and triacetylated derivatives exert similar inhibitory activity, whereas the diacetylated ones are more potent inhibitors. In conclusion, acetylated phenolics exert the same or even higher antithrombotic activity compared to the biological activity of the initial one.  相似文献   

16.
Estrogenic activity in white and red wine extracts   总被引：8，自引：0，他引：8  
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17.
The solubilization site of two betalain pigments, namely, betanin and indicaxantin, into l-alpha-dipalmitoyl-phosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) vesicles was investigated by a spectrophotometric study. Pigment absorbance was monitored by varying phospholipid concentration, at a constant temperature that was varied in a range including the main phase transition temperature (Tm) of the relevant phospholipid bilayer. Maximum betanin absorption increased with the increase of DPPC concentration within the entire temperature range, reaching a plateau. The binding constant (Kb) of the pigment, calculated according to a pseudo-two-phase model, varied with the temperature, indicating that betanin is located at the hydrophobic interior of the bilayer. Other measurements of binding of betanin to DMPC and of indicaxanthin to either DPPC or DMPC vesicles ruled out that these compounds were solubilized in the hydrophobic interior of these bilayers.  相似文献   

18.
A method using HPLC analysis has been used to compare the level of resveratrol and its derivatives, piceid, pterostilbene and epsilon-viniferin, in grapevine berries of three Vitis vinifera varieties. The concentration of these compounds has been evaluated in healthy and Botrytis cinerea infected grape clusters, both in natural vineyard conditions and in response to UV elicitation.  相似文献   

19.
In the skin of cv. Napoleon table grapes, the anthocyanins malvidin 3-glucoside (and its acetyl and p-coumaroyl derivatives), cyanidin 3-glucoside, peonidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, and delphinidin 3-glucoside were identified by HPLC-DAD-MS. In addition, quercetin 3-glucoside and 3-glucuronide, caffeoyltartaric, piceid, and resveratrol were also detected. The content of most phenolics remained quite constant during postharvest refrigerated storage (10 days at 0 degrees C) while the resveratrol derivatives increased 2-fold. Postharvest treatments of grapes with UVC and UVB light induced a large increase in resveratrol derivatives (3- and 2-fold, respectively). This means that a serving of mature Napoleon grapes (200 g) provides approximately 1 mg of resveratrol, which is in the range of the amount supplied by a glass of red wine. This can be increased to 2 or 3 mg of resveratrol per serving in grapes that have been irradiated with UVB or UVC, respectively. These results show that refrigerated storage and UV irradiation of table grapes can be beneficial in terms of increasing the content of potentially health-promoting phenolics.  相似文献   

20.
The stable isotope characterization of resveratrol 1 from Polygonum cuspidatum and of related natural stilbenes 11 and 12 obtained by hydrolysis of the corresponding glucosides 2 and 3 from Rheum is reported. The C(6)-C(2)-C(6) framework of suitably protected derivatives of 1, 2, and 3 has been degraded with ozone to the C(6)-C(1) aldehydes 4, 5, 9, and 10, retaining all hydrogen atoms of the precursors. The natural and synthetic derivatives are characterized and distinguished by natural abundance deuterium nuclear magnetic resonance studies. In the case of anisaldehyde 4 the two series show, as expected, the characteristic difference of the aromatic labeling. The formyl deuterium contents of 4 and 5 from resveratrol are remarkably different, seemingly reflecting the different enrichments existing between positions 3 and 2, respectively, of the phenylpropanoid precursor. The positional delta(18)O values of the extractive materials 1-3 were also determined. In this instance a selective deoxygenation procedure was adopted, leading from 1 to the products 6, 7, and 8. The delta(18)O values of the latter compounds reveal, respectively, those at position 4' and positions 3 and 5 of 1. Similarly, the phenolic products 11 and 12 were converted into 13 and 14. From the delta(18)O values of the single components it is possible to design a detailed map of the oxygen fractionations which characterizes the stilbenes 1-3. In particular, the oxygen present at position 4' of the phenylpropanoid moiety of 1-3 shows delta(18)O values of +11.5, +1.8, and +6.7 per thousand, respectively. Moreover, the phenolic oxygen atom at position 3' of rhapontin 3 shows a value of +11.7 per thousand. The data are compared with those previously obtained on structurally related compounds. These results show the utility of simple chemical degradations in the stable isotope characterization of structurally complex food components.  相似文献   

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