Non-typhoidal Salmonella enterica serovars continue to be an important food safety issue worldwide. Cranberry (Vaccinium macrocarpon Ait) fruits possess antimicrobial properties due to their various ...acids and phenolic compounds; however, the underlying mechanism of actions is poorly understood. We evaluated the effects of cranberry extracts on the growth rate of Salmonella enterica serovars Typhimurium, Enteritidis and Heidelberg and on the transcriptomic profile of Salmonella Enteritidis to gain insight into phenotypic and transcriptional changes induced by cranberry extracts on this pathogen. An ethanolic extract from cranberry pomaces (KCOH) and two of its sub-fractions, anthocyanins (CRFa20) and non-anthocyanin polyphenols (CRFp85), were used. The minimum inhibitory (MICs) and bactericidal (MBCs) concentrations of these fractions against tested pathogens were obtained using the broth micro-dilution method according to the Clinical Laboratory Standard Institute's guidelines. Transcriptional profiles of S. Enteritidis grown in cation-adjusted Mueller-Hinton broth supplemented with or without 2 or 4 mg/ml of KCOH were compared by RNASeq to reveal gene modulations serving as markers for biological activity. The MIC and MBC values of KCOH were 8 and 16 mg/mL, respectively, against all tested S. enterica isolates. The MIC value was 4 mg/mL for both CRFa20 and CRFp85 sub-fractions, and a reduced MBC value was obtained for CRFp85 (4 mg/ml). Treatment of S. Enteritidis with KCOH revealed a concentration-dependent transcriptional signature. Compared to the control, 2 mg/ml of KCOH exposure resulted in 89 differentially expressed genes (DEGs), of which 53 and 36 were downregulated and upregulated, respectively. The upregulated genes included those involved in citrate metabolism, enterobactin synthesis and transport, and virulence. Exposure to 4 mg/ml KCOH led to the modulated expression of 376 genes, of which 233 were downregulated and 143 upregulated, which is 4.2 times more DEGs than from exposure to 2 mg/ml KCOH. The downregulated genes were related to flagellar motility, Salmonella Pathogenicity Island-1 (SPI-1), cell wall/membrane biogenesis, and transcription. Moreover, genes involved in energy production and conversion, carbohydrate transport and metabolism, and coenzyme transport and metabolism were upregulated during exposure to 4 mg/ml KCOH. Overall, 57 genes were differentially expressed (48 downregulated and 9 upregulated) in response to both concentrations. Both concentrations of KCOH downregulated expression of hilA, which is a major SPI-1 transcriptional regulator. This study provides information on the response of Salmonella exposed to cranberry extracts, which could be used in the control of this important foodborne pathogen.
The six major anthocyanins found in the burgundy coloured fruits of Staghorn sumac (Rhus typhina L.) were isolated and the structures of four compounds were determined by NMR spectroscopic methods as ...being: 7-O-methyl-delphinidin-3-O-(2″galloyl)-β-d-galactopyranoside; 7-O-methyl-cyanidin-3-O-(2″galloyl)-β-d-galactopyranoside; 7-O-methyl-delphinidin-3-O-(2″'galloyl)-β-d-galactopyranoside-4-vinyl-catechol-3″-O-β-d-glucopyranoside; and 7-O-methyl-cyanidin-3-O-(2″'galloyl)-β-d-galactopyranoside-4-vinyl-catechol-3″-O-β-d-glucopyranoside, respectively. Additionally, two related anthocyanin compounds, cyanidin-3-O-(2″galloyl)-β-d-galactopyranoside and 7-O-methyl-cyanidin-3-O-β-d-galactopyranoside were also recovered, with NMR spectroscopic values closely matching previous reports from other plant species. The prevalence of 7-O-methyl anthocyanins and their galloylated derivatives in sumac is highly unusual, and warrants special attention. Additionally, the in planta occurrence of two 7-O-methyl-pyranoanothocyanin-vinyl-catechol aglycones, Sumadin A and Sumadin B, and their derivatives is noted. To our knowledge, E-ring glycosylated vinyl-catechol pyranoanthocyanins were previously unknown.
Herein is detailed the development and validation of an ultra-micro-scale-fractionation (UMSF) technique for the discovery of plant-based, bioactive molecules, coupling the advantages of ...ultra-performance liquid chromatography mass spectrometry (UPLC-MS) separations with microtiter plate-based bioassay screens. This novel one-step approach simultaneously uses UPLC to collect chemical profile information, while performing high-resolution fractionation, greatly improving workflow compared to methods relying on high-performance liquid chromatography (HPLC), solid phase extraction or flash systems for chromatographic separations. Using the UMSF technique, researchers are able to utilize smaller quantities of starting materials, reduce solvent consumption during fractionation, reduce laborious solvent dry down times, replace costly single-use solid-phase-extraction cartridges with reusable analytical-sale UPLC columns, reduce fractionation times to less than 10 min, while simultaneously generating chemical profile data of active fractions and enjoying superior chromatographic resolution. Using this technique, individual bioactive components can be readily purified, identified, and bioassayed in one step from crude extracts, thereby eliminating ambiguous synergistic effects often reported in plant-based natural products research. A successful case-study is presented illustrating the versatility of this technique in identifying lupulone as the principal cytotoxic component from hops (
L.), using a brine shrimp (
) model. These results confirm and expand upon previous cell-based bioassay studies using a more complex, multicellular organism, and add to our understanding of structure-function activity relationships for secondary metabolites in hops and the
plant family.
A survey was conducted in the Maritimes region of eastern Canada to measure the phytochemical diversity of prenylchalcone, soft resins (alpha & beta acids), and flavonol constituents from 30 unique ...wild-growing populations of hops (
L.). Based on cone chemometrics, the majority of accessions (63.3%) are native
ssp.
, with cones containing both xanthogalenol and 4'-
-methyl xanthohumol as chemotaxonomic indicator molecules. Interestingly, the leaves of all verified
ssp.
accessions accumulated high proportions (>0.20 total flavonols) of two acylated flavonol derivatives (kaempferol-3-
-(6''-
-malonyl)-β-D-glucopyranoside; quercetin-3-
-(6''-
-malonyl)-β-D-glucopyranoside), both previously unreported from hops leaves. The native
accessions examined possess only trace amounts of this compound in their leaves (<0.10 total flavonols), suggesting its potential utility as a novel, leaf-derived chemotaxonomic marker for subspecies identification purposes. A leaf-derived taxonomic marker is useful for identifying wild-growing accessions, as leaves are present throughout the entire growing season, whereas cones are only produced late in summer. Additionally, the collection of cones from 10-meter tall wild plants in overgrown riparian habitats is often difficult. The total levels of alpha acids, beta acids, and prenylchalcones in wild-collected Maritimes
cones are markedly higher than those previously reported for
individuals in the westernmost extent of its native range and show potentially valuable traits for future cultivar development, while some may be worthy of immediate commercial release. The accessions will be maintained as a core germplasm resource for future cultivar development.
► The first comprehensive study on the phytochemical composition of Rhus hirta fruit. ► R. hirta fruit had higher antioxidant activities than common fruits and vegetables. ► Polyphenols were found to ...be the main contributor to the antioxidant activity. ► A novel group of anthocyanins were recognised and tentatively identified.
Staghorn sumac (Rhus hirta L.) is a native tree in Eastern Canada whose fruit has been used by aboriginal peoples to treat various illnesses, and has recently been found to be a good source of antioxidants. However, the phytochemical composition of R. hirta is not known. In this study, we used Four highly accepted assays and confirmed its FRAP, ORAC, β-CLAMS and PCL values to be 79.95μmol AAE/g DW, 1544μmol TE/g DW, RAA 129% and 4513μmol TE/g DW, respectively. The antioxidant activities correlated positively to the total polyphenols content, which was higher in the ethanolic extract (81.6mg GAE/ g DW) compared to the water extract (46.3mg GAE/g DW), suggesting polyphenols play an important role. Quantitative data from UHPLC and qualitative studies using HPLC-DAD-MS showed that in addition to commonly found phenolic acids, flavonoids and anthocyanins, R. hirta fruit contained a novel group of unique anthocyanins with aglycones (anthocyanidins) at 449, 419 and 433Da. Further studies on the identification and their health beneficial effects are being conducted.
•First report on cell-based antioxidant activity of pyranoanthocyanins and other polyphenols of staghorn sumac fruits.•First report on anti-inflammatory effect of pyranoanthocyanins and other ...polyphenols of staghorn sumac fruits.•First report on potential mechanism of anti-inflammatory effect of staghorn pyranoanthocyanins•Results suggest staghorn sumac or its major components may be beneficial to inflammation related diseases such as IBD.
The antioxidant and anti-inflammatory activities of the novel pyranoanthocyanins and other polyphenols from staghorn sumac (Rhus hirta L.) were examined. The results not only confirmed the previously found antioxidant activity by chemical based assays, but more importantly strong anti-inflammatory activity for the first time in cell-based assays. These unique compounds significantly inhibited the production of pro-inflammatory cytokine IL-8 production stimulated by H2O2 and TNF-α. It was also found that these activities of the crude extract were primarily from the individual polyphenols, particularly the unique pyranoanthocyanins and 7-methoxyanthocyanins. Pyranoanthocyanin 1, in particular, showed a markedly strong anti-inflammatory activity at 1 M, followed by pyranoanthocyanin 2 and a 7-methoxyanthocyanin 5. Further mechanism investigation showed that the anti-inflammatory activity was likely mediated through inhibition of NF-κB activation via phosphorylation of IκBα. Results from the present study warrant further investigation into the in vivo anti-inflammatory effect and health benefits using animal models or human subjects.
Flax secoisolariciresinol diglucoside (SDG) lignan is a natural phytoestrogen for which a positive role in metabolic diseases is emerging. Until recently however, much less was known about SDG and ...its monoglucoside (SMG) biosynthesis. Lately, flax UGT74S1 was identified and characterized as an enzyme sequentially glucosylating secoisolariciresinol (SECO) into SMG and SDG when expressed in yeast. However, the amino acids critical for UGT74S1 glucosyltransferase activity were unknown. A 3D structural modeling and docking, site-directed mutagenesis of five amino acids in the plant secondary product glycosyltransferase (PSPG) motif, and enzyme assays were conducted. UGT74S1 appeared to be structurally similar to the Arabidopsis thaliana UGT72B1 model. The ligand docking predicted Ser357 and Trp355 as binding to the phosphate and hydroxyl groups of UDP-glucose, whereas Cys335, Gln337 and Trp355 were predicted to bind the 7-OH, 2-OCH3 and 17-OCH3 of SECO. Site-directed mutagenesis of Cys335, Gln337, His352, Trp355 and Ser357, and enzyme assays revealed an alteration of these binding sites and a significant reduction of UGT74S1 glucosyltransferase catalytic activity towards SECO and UDP-glucose in all mutants. A complete abolition of UGT74S1 activity was observed when Trp355 was substituted to Ala355 and Gly355 or when changing His352 to Asp352, and an altered metabolite profile was observed in Cys335Ala, Gln337Ala, and Ser357Ala mutants. This study provided for the first time evidence that Trp355 and His352 are critical for UGT74S1's glucosylation activity toward SECO and suggested the possibility for SMG production in vitro.
Cyanidin 3-0-glucoside (CG) is a polyphenol with potential health benefits. In this study, we investigated, for the first time, the cardioprotective effects of CG in an animal model of myocardial ...infarction (MI), a major cause of death worldwide. Sham and MI rats were administered CG (10 mg kg
−1
day
−1
) daily for one week prior to surgery, and 8 weeks post-surgery. Echocardiography was performed to assess cardiac structure and function at 4 and 8 weeks. At 4 weeks, MI rats had significantly lower body mass when compared to control rats, and CG administration significantly prevented this decrease. Four-week MI rats also showed significantly increased left ventricle dilation, end systolic and end diastolic volumes in comparison to controls, and CG significantly prevented these adverse changes. Ejection fraction was significantly lower in 4-week MI rats in comparison to controls, and CG had no effect on this parameter. At 8 weeks, body mass was significantly lower in MI rats when compared to control rats, and CG significantly prevented this decrease. At 8 weeks, MI rats showed a significant increase in left ventricle dilation and isovolumic relaxation time, while ejection fraction was significantly lower when compared to controls; these parameters were not altered by CG treatment. Eight-week MI rats had significantly higher level of oxidative stress in heart tissue in comparison to controls, and CG administration did not prevent this increase. In conclusion, administration of CG was able to significantly preserve body mass in both 4 and 8 weeks MI rats, as well as significantly prevent cardiac dilation in 4 weeks MI rats. However, CG was unable to sustain this cardioprotection, as cardiac structure and function were not significantly improved in 8 weeks MI rats.
Cyanidin 3-0-glucoside (CG) is a polyphenol with potential health benefits.
Staghorn sumac fruits were found to contain a rich assortment of anthocyanins, including pyranoanthocyanins displaying distinctive UV–Vis absorption spectra. Structures were characterized by ...UPLC–ESI-MS and NMR spectroscopy.
•Four anthocyanin compounds from Staghorn sumac were fully characterized using 1H, 13C and 2D NMR spectroscopic techniques.•7-O-methyl anthocyanins were discovered, discounting earlier accounts of 3′O-methyl derivatives.•Two pyranoanthocyanin aglycones (Sumadin A and Sumadin B) are also reported.
The six major anthocyanins found in the burgundy coloured fruits of Staghorn sumac (Rhus typhina L.) were isolated and the structures of four compounds were determined by NMR spectroscopic methods as being: 7-O-methyl-delphinidin-3-O-(2″galloyl)-β-d-galactopyranoside; 7-O-methyl-cyanidin-3-O-(2″galloyl)-β-d-galactopyranoside; 7-O-methyl-delphinidin-3-O-(2″′galloyl)-β-d-galactopyranoside-4-vinyl-catechol-3″-O-β-d-glucopyranoside; and 7-O-methyl-cyanidin-3-O-(2″′galloyl)-β-d-galactopyranoside-4-vinyl-catechol-3″-O-β-d-glucopyranoside, respectively. Additionally, two related anthocyanin compounds, cyanidin-3-O-(2″galloyl)-β-d-galactopyranoside and 7-O-methyl-cyanidin-3-O-β-d-galactopyranoside were also recovered, with NMR spectroscopic values closely matching previous reports from other plant species. The prevalence of 7-O-methyl anthocyanins and their galloylated derivatives in sumac is highly unusual, and warrants special attention. Additionally, the in planta occurrence of two 7-O-methyl-pyranoanothocyanin-vinyl-catechol aglycones, Sumadin A and Sumadin B, and their derivatives is noted. To our knowledge, E-ring glycosylated vinyl-catechol pyranoanthocyanins were previously unknown.
A novel mixed mode HPLC method using a column combining both ion-exchange and reversed-phase separation mechanisms has been developed to facilitate analysis of anthocyanins in grapes. Chromatographic ...performance and subsequent analysis of anthocyanidin diglucosides and acylated compounds are significantly improved using the new column, compared to those associated with conventional C18 reversed-phase methods. The mixed mode column produces a distinctive eluting pattern for the different anthocyanin subgroups, avoiding overlaps found with C18 columns. The enhanced chromatographic resolution provides nearly complete separation of 37 anthocyanin types, and permits detection of delphinidin 3-
O-(6″-
O-caffeoyl) β-
d-glucoside for the first time in extracts of skins from Concord grapes.
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