Two new dibenzocyclooctane lignans, kadsurindutins A (1) and B (2), were isolated from the stems of Kadsura induta, together with the known, structurally related lignans schisantherin L (3), schisantherin P (4), kadsulignan L (5), and neokadsuranin (6). Their structures and configurations were elucidated by spectroscopic methods (UV, ORD, CD, IR, 1D- and 2D-NMR) in combination with mass-spectrometric (HR-MS) techniques. Compounds 1, 5, and 6 showed in vitro antiviral effects on hepatitis B virus. 相似文献
Flaxseed is one of the richest sources of lignans that are converted to enterolactone by the intestinal microflora. Enterolactone has been suggested to be the prime active compound mediating atherosclerosis-protective effects that were shown for flaxseed. The effects of a 1-wk intervention with 0.4 g of flaxseed/kg body weight per day on enterolactone plasma levels in seven healthy men revealed that all participants (PAs) responded with enhanced enterolactone plasma levels. Proteome analysis of peripheral blood mononuclear cells (PBMC) from donors before, during, and after the intervention showed that flaxseed consumption affected significantly the steady-state levels of 16 proteins of which four were altered in a similar manner when blood mononuclear cells were exposed ex vivo to enterolactone. Enhanced levels of peroxiredoxin and reduced levels of the long-chain fatty acid beta-oxidation multienzyme complex may be taken as indicators of a reduced oxidative stress whereas reduced levels of glycoprotein IIIa/II could indicate improved protection from thrombotic and inflammatory processes. In conclusion, the blood mononuclear cell proteome responds to dietary flaxseed intake with changes in a number of atherosclerosis-relevant proteins that may be taken as biomarkers of exposure and some of these changes observed can be attributed to the action of the lignan metabolite enterolactone. 相似文献
Three lignans, (7S,8S,7'S,8'S)-3,3',4'-trihydroxy-4-methoxy-7,7'-epoxylignan, meso-(rel 7S,8S,7'R,8'R)-3,4,3',4'-tetrahydroxy-7,7'-epoxylignan, and (E)-4,4'-dihydroxy-7,7'-dioxolign-8(8')-ene, together with 10 known compounds, were isolated from the leaves of Larrea tridentata. The structures of the new compounds were determined primarily from 1D and 2D NMR spectroscopic analysis. Their antioxidant activities against intracellular reactive oxygen species were evaluated in HL-60 cells. 相似文献
Two lignans, isochaihulactone and chaihunaphthone, together with eleven known compounds were isolated from the root of Bupleurum scorzonerifolium. Their structures were established on the basis of spectral evidence. In biological testing, eugenin and saikochromone potently inhibited CD28-costimulated activation of human peripheral blood T cells. 相似文献
Estrogen plays a major role in breast cancer development and progression. Breast tissue and cell lines contain the necessary enzymes for estrogen synthesis, including aromatase and 17β-hydroxysteroid dehydrogenase (17β-HSD). These enzymes can influence tissue exposure to estrogen and therefore have become targets for breast cancer treatment and prevention. This study determined whether the isoflavone genistein (GEN) and the mammalian lignans enterolactone (EL) and enterodiol (ED) would inhibit the activity of aromatase and 17β-HSD type 1 in MCF-7 cancer cells, thereby decreasing the amount of estradiol (E2) produced and consequently cell proliferation. Results showed that 10 μM EL, ED and GEN significantly decreased the amount of estrone (E1) produced via the aromatase pathway by 37%, 81% and 70%, respectively. Regarding 17β-HSD type 1, 50 μM EL and GEN maximally inhibited E2 production by 84% and 59%, respectively. The reduction in E1 and E2 production by EL and the reduction in E2 production by GEN were significantly related to a reduction in MCF-7 cell proliferation. 4-Hydroxyandrostene-3,17-dione (50 μM) did not inhibit aromatase but inhibited the conversion of E1 to E2 by 78%, suggesting that it is a 17β-HSD type 1 inhibitor. In conclusion, modulation of local E2 synthesis is one potential mechanism through which ED, EL and GEN may protect against breast cancer. 相似文献
Further study on the constituents from the bark of Tabebuia impetiginosa (Mart. ex DC) Standley afforded twelve compounds, consisting of four iridoid glycosides, one phenylethanoid glycoside, five phenolic glycosides, and one lignan glycoside, along with seven known compounds. The structures of these compounds were determined based on the interpretation of their NMR and MS measurements and by chemical evidence. 相似文献
Lignin and lignans share monolignols as common precursors and are both potentially involved in plant defence against pathogens.
In this study, we investigated the effects of fungal elicitors on lignin and lignan metabolism in flax (Linum usitatissimum) cell suspensions. Cell suspension cultures of flax were treated with elicitor preparations made from mycelium extracts of
Botrytis cinerea, Phoma exigua and Fusarium oxysporum F ssp lini. Elicitors induced a rapid stimulation of the monolignol pathway, as confirmed by the increase in PAL (phenylalanine ammonia-lyase, EC 4.1.3.5), CCR (cinnamoyl-CoA reductase EC 1.2.1.44) and CAD (cinnamyl alcohol dehydrogenase EC 1.1.1.195) gene expression and PAL activity. At the same time, CCR activity only increased
significantly in F. oxysporum-treated cells 24 h post elicitation. On the other hand, CAD activity measured for coniferyl alcohol formation was transiently
decreased but a substrate-specific activation of CAD activity was observed in F. oxysporum-treated cells when using sinapyl alcohol as substrate. The accumulation of monolignol-derived products varied according to
the elicitor used. B. cinerea or P. exigua-elicited cell cultures were characterised by a reinforcement of the cell wall by a deposit of 8-O-4′-linked non-condensed
lignin structures and phenolic monomers, while at the same time no stimulation of 8-8′-linked lignan or 8-5′-linked phenylcoumaran
lignan accumulation was observed. Additionally, elicitation of cell cultures with F. oxysporum extracts even triggered a strong incorporation of monolignols in the non condensed labile ether-linked lignin fraction concomitantly
with a decrease in lignan and phenylcoumaran lignan accumulation. Several hypotheses are proposed to explain the putative
role of these compounds in the defence response of flax cells against pathogens.
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C. Hano and M. Addi contributed equally to this work. 相似文献
A time-resolved fluoroimmunoassay (TR-FIA), with europium labeled phytoestrogens as tracers, was developed for the quantitative determination of enterolactone, genistein and daidzein in human urine. The aim was to create a method for the screening of large populations in order to assess the possible correlations between the urinary levels and the risk of Western diseases.
After the synthesis of the 5′-carboxymethoxy derivative of enterolactone and 4′-O-carboxymethyl derivatives of daidzein and genistein, the respective compound was coupled to bovine serum albumin and then used as an antigen in the immunization of rabbits. The same derivatives of the phytoestrogen were used in preparing the europium tracers. After the enzymatic hydrolysis, the TR-FIA was carried out using the Victor 1420 multilabel counter. The method has sufficient sensitivity to measure the phytoestrogens at concentrations even below 5 nmol/l. The intra- and inter-assay coefficients of variation, at three different concentrations, varied from 1.9 to 5.3 and from 2.4 to 9.7, respectively.
We measured urinary enterolactone, genistein and daidzein in 215 samples from Finnish healthy women and found that more than 50% of the values ranged between 1 and 7, <0.1 and 0.6 and below 0.6 μmol/24 h, respectively. The TR-FIA method including only a hydrolysis step gave higher values than those measured by gas chromatography–mass spectrometry (GC–MS). However, the assay results by the present method showed strong correlation with those obtained by GC–MS. It is concluded that the TR-FIA is suitable for population screening of urinary phytoestrogens. 相似文献
Sixteen known lignans were isolated from the 95% alcohol extract of the whole plant of Serissa japonica (Thunb.) Thunb., including nine furofurans (1–9), three tetrahydrofurans (10–12) and four arylnaphthalenes (13–16). In the present report, compounds (+)-epipinoresinol (1), (+)-1-hydroxy-6-epipinoresinol 4,4″-di-O-methyl ether (3), (−)-pinoresinol (4), (+)-8-hydroxypinoresinol (6), pseuderesinol (7), (+)-1-hydroxysyringaresinol (8), (−)-(7′S,8S,8′R)-4,4′-dihydroxy-3,3′,5,5′-tetramethoxy-7′,9-epoxylignan-9′-ol-7-one (10), wikstrone (11), 7'-(+)-oxomatairesinol (12), (+)-cycloolivil (13), (+)-isolariciresinol (14), 5-methoxy-(+)-isolariciresinol (15) and cyclolignans (16) were reported from the Serissa genus for the first time, and compounds (+)-lirioresinol A (2) and (−)-lirioresinol B (5) were firstly isolated from the plant. Their structures were elucidated on the basis of extensive spectroscopic and chemical analyses. Moreover, the chemotaxonomic significance of the isolated compounds is discussed. 相似文献
A pair of new 3′,7-epoxy-8,4′-oxyneolignan enantiomers [(+)-1 and (−)-1] as well as a known phenylpropanoid (2) were isolated from the seeds of Croton tiglium Linn. Their structures were established based on extensive spectroscopic analyses. The absolute configurations of (+)-1 and (−)-1 were determined by NMR data calculations and electronic circular dichroism calculations. All compounds were isolated from the genus Croton for the first time. Particularly, (+)-1 and (−)-1 were the first 3′,7-epoxy-8,4′-oxyneolignanes reported in Croton. The chemotaxonomic significance of these compounds was discussed. 相似文献