Showing papers on "Flavanone published in 2011"
TL;DR: In this article, several flavonoids belonging to the chalcone structural groups were screened for their capacity to reduce the production of QS-controlled factors in the opportunistic pathogen Pseudomonas aeruginosa (strain PAO1).
Abstract: Preliminary screening of the Malagasy plant Combretum albiflorum for compounds attenuating the production of quorum sensing (QS)-controlled virulence factors in bacteria led to the identification of active fractions containing flavonoids. In the present study, several flavonoids belonging to the flavone, flavanone, flavonol and chalcone structural groups were screened for their capacity to reduce the production of QS-controlled factors in the opportunistic pathogen Pseudomonas aeruginosa (strain PAO1). Flavanones (i.e. naringenin, eriodictyol and taxifolin) significantly reduced the production of pyocyanin and elastase in P. aeruginosa without affecting bacterial growth. Consistently, naringenin and taxifolin reduced the expression of several QS-controlled genes (i.e. lasI, lasR, rhlI, rhlR, lasA, lasB, phzA1 and rhlA) in P. aeruginosa PAO1. Naringenin also dramatically reduced the production of the acylhomoserine lactones N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL) and N-butanoyl-l-homoserine lactone (C4-HSL), which is driven by the lasI and rhlI gene products, respectively. In addition, using mutant strains deficient for autoinduction (ΔlasI and ΔrhlI) and LasR- and RhlR-based biosensors, it was shown that QS inhibition by naringenin not only is the consequence of a reduced production of autoinduction compounds but also results from a defect in the proper functioning of the RlhR–C4-HSL complex. Widely distributed in the plant kingdom, flavonoids are known for their numerous and determinant roles in plant physiology, plant development and in the success of plant–rhizobia interactions, but, as shown here, some of them also have a role as inhibitors of the virulence of pathogenic bacteria by interfering with QS mechanisms.
206 citations
TL;DR: The qualitative and quantitative flavonoid and furocoumarin composition of crude sour orange (Citrus aurantium L.) juice was determined via reverse-phase LC-DAD-ESI-MS-MS analysis as discussed by the authors.
106 citations
TL;DR: It was found that the flavanone behaved as a reversible inhibitor of the enzyme and that it was a mixed-I type or a non-competitive inhibitor with l-tyrosine or l-DOPA as substrates, respectively.
74 citations
TL;DR: In this article, the authors investigated the composition of Citrus myrtifolia Raf. (chinotto) flavedo, albedo and carpel membranes from green and ripe fruits, as well as seeds and leaves, for the first time for their flavonoid and furocoumarin composition.
65 citations
TL;DR: Nine flavonoid isolated from the ethyl acetate extract of Pycnanthus angolensis were assayed for their potential apoptosis induction activities in human hepatoma HuH‐7 cells and caspase activity assays confirmed the apoptosis inducing activity of these flavonoids.
Abstract: Nine flavonoids isolated from the ethyl acetate extract of Pycnanthus angolensis were assayed for their potential apoptosis induction activities in human hepatoma HuH-7 cells. These flavonoids include eight isoflavones, namely irilone (1), tectorigenine (2), formononetin (3), genistein (4), 2'-hydroxybiochanin A (5), mixture of biochanin A (6) and prunetin (7), and 4',7-dihydroxy-2'-methoxyisoflavan (8), and the flavanone liguiritigentin (9). Their chemical structures were characterized by spectroscopic methods including 2D NMR experiments. Methodology for cell death detection included the LDH assay, Hoechst staining, TUNEL staining and general caspase-3-like activity assay. The compounds tested showed higher apoptosis induction profiles in HuH-7 cells compared with the control. Caspase activity assays confirmed the apoptosis inducing activity of these flavonoids.
61 citations
TL;DR: The structure of the flavonoids was shown to affect NF-κB activation and the effects of flavonoid structure on inhibition of NF-σB were investigated.
53 citations
TL;DR: The binding of flavanone glucuronides to HSA was investigated by fluorescence spectroscopy and it was found that the affinity of glucuronide for HSA is close to that of naringenin and hesperetin themselves.
Abstract: Naringenin and hesperetin glycosides are the major polyphenols (flavanones) of citrus fruits and juices and are thought to participate in the cardioprotective effects of diets rich in plant products. Naringenin and hesperetin glucuronides (resulting from conjugation at the A- or B-ring) are the main circulating metabolites in humans and their binding to human serum albumin (HSA) is expected to modulate their half-life in plasma and tissue distribution. In this work, the binding of flavanone glucuronides to HSA was investigated by fluorescence spectroscopy. Binding constants in the range of 3-9 × 10(4) M(-1) were estimated. The affinity of glucuronides for HSA is close to that of naringenin and hesperetin themselves. Competition experiments in the presence of the fluorescent probes dansylsarcosine and quercetin were used to gain information on the flavanone binding site. Naringenin and hesperetin chalcones were also included for comparison as their glucuronides too were detected in the general circulation. Naringenin and hesperetin chalcones spontaneously undergo cyclization back to the parent flavanones under neutral conditions. The cyclization was significantly slowed down by HSA but led to a racemic mixture of (2R) and (2S) flavanones in the absence or presence of HSA.
44 citations
TL;DR: The kinetic study of the anaerobic biotransformation showed both activities were exceptionally fast compared to the reported conversion by other an aerobic bacteria.
Abstract: A Gram-negative anaerobic microorganism, MRG-1, isolated from human intestine showed high activities of deglycosylation and reduction of daidzin, based on rapid TLC analysis. A rod-shaped strain MRG-1was identified as a new species showing 91.0% homology to Coprobacillus species, based on 16S rRNA sequence analysis. The strain MRG-1 showed β-glucosidase activity toward daidzin and genistin, and daidzein and genistein were produced, respectively. However, the strain MRG-1 did not react with flavone glycosides, flavanone glycosides, and isoflavone C-glucoside. Besides, MRG-1 showed stereoselective reductase activity to isoflavone, daidzein, genistein, 7-hydroxyisoflavone, and formononetin, resulting in the formation of corresponding R-isoflavanone enantiomers. The new isoflavanones of 7-hydroxyisoflavanone and dihydroformononetin were characterized by NMR, and the absolute configurations of the enantiomers were determined with CD spectroscopy. The kinetic study of the anaerobic biotransformation showed both activities were exceptionally fast compared to the reported conversion by other anaerobic bacteria.
37 citations
TL;DR: It is found that the peroxygenase of the fungus Agrocybe aegerita (AaeAPO) catalyzes the H2O2-dependent hydroxylation of diverse flavonoids, yielding preferentially monohydroxylated products.
35 citations
TL;DR: Novozym 435 proved to be a more efficient biocatalyst than Lipozyme RM IM and derivatives preserved the antiradical activity of the flavanone glucoside and their solubility notably increased in the hydrophobic medium 1-octanol.
33 citations
TL;DR: The phytochemical study herein was guided by preliminary antioxidant tests, namely, β-carotene protection and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and isolated compounds were assayed against intracellular reactive oxygen species (ROS) and human embryonic kidney HEK-293 and human melanoma M14 cancer cell growth.
TL;DR: The bioassay-guided purification of the ethanolic extract from the leaves of Piper hispidum led to the isolation of one new amide, N -2-(3′,4′,5′-trimethoxyphenyl)ethyl-2-hydroxybenzamide (1 ) as well as two known chalcones 2′-hydrox-3′-4,6′, 6′-decimethoxychalcone (2 ); 2′, 4′-dihydroxy-6′-meth
TL;DR: It is suggested that flavanone derivatives control the expression of cell cycle regulatory proteins, which blocks G1 cell cycle progression and inhibits the clonogenicity of HCT116 cells.
Abstract: Naringenin has been shown to display various biological effects such as antioxidant, anticancer, anti-inflammatory, and antiviral activities. Taxifolin inhibits the production of lipopolysaccharide-induced prostaglandin E, and fustin suppresses the activity of acetylcholinesterase. They all belong to flavanone which is a class of flavonoids with a C6-C3-C6 skeleton. Since the anticancer activities of flavanone derivatives have rarely been reported, we examined the effects of 26 flavanone derivatives on HCT116 colorectal cancer cells. Our results suggest that flavanone derivatives control the expression of cell cycle regulatory proteins, which blocks G1 cell cycle progression and inhibits the clonogenicity of HCT116 cells. In addition, in order to design flavanone derivatives that show better anticancer activity, structure-activity relationships were examined.
TL;DR: In this article, a new and previously reported flavanone glycoside were isolated from 50% ethanol extract of litchi (Litchi chinensis Sonn.) seeds using a bioactivity-guided method.
TL;DR: It was found that the hydroxylation on position 3′ of flavonol significantly improves the binding affinity for HSA, and the values of log10(Ka) are proportional to the number of binding sites (n), which confirms the method used here is suitable to study the interaction between Citrus flavanones and HSA.
Abstract: Much of the bioactivities of Citrus flavanones significantly appear to impact blood and microvascular endothelial cells. It is essential to investigate the interaction between Citrus flavanones and serum albumin to verify the effect of flavanone structures on the distribution and transportation in blood. The interactions between flavonoids and proteins have attracted great interest among researchers. The work in here mainly concerns about the binding interaction between Citrus flavanones and human serum albumin (HSA) in vitro. The methoxylation of tangeretin improved the affinity for HSA by 100 times. The 2,3-double bond in conjugation with a 4-oxo group plays an important role for the affinity for HSA. The affinity of apigenin for HSA is about 10,000-times higher than that of naringenin. It was found that the hydroxylation on position 3' of flavonol significantly improves the binding affinity for HSA. The affinity of quercetin (3', 4') for HSA is about 100-times higher than that of kaempferol (4'). The hydroxylation on position 3' of flavone slightly improves the binding affinity for HSA. The affinity of luteolin for HSA is about 1.38-times higher than that of apigenin. The values of log10(Ka) are proportional to the number of binding sites (n), which confirms the method used here is suitable to study the interaction between Citrus flavanones and HSA.
TL;DR: The results support the idea that substrate-driven reactivity alteration of the Fe-oxo active species may occur in the active site of non-heme dioxygenases.
Abstract: This review details recent progresses in the flavonoid biotransformation by bacterial non-heme dioxygenases, biphenyl dioxygenase (BDO), and naphthalene dioxygenase (NDO), which can initially activate biphenyl and naphthalene with insertion of dioxygen in stereospecfic and regiospecific manners. Flavone, isoflavone, flavanone, and isoflavanol were biotransformed by BDO from Pseudomonas pseudoalcaligenes KF707 and NDO from Pseudomonas sp. strain NCIB9816-4, respectively. In general, BDO showed wide range of substrate spectrum and produced the oxidized products, whereas NDO only metabolized flat two-dimensional substrates of flavone and isoflavone. Furthermore, biotransformation of B-ring skewed substrates, flavanone and isoflavanol, by BDO produced the epoxide products, instead of dihydrodiols. These results support the idea that substrate-driven reactivity alteration of the Fe-oxo active species may occur in the active site of non-heme dioxygenases. The study of flavonoid biotransformation by structurally-well defined BDO and NDO will provide the substrate structure and reactivity relationships and eventually establish the production of non-plant-originated flavonoids by means of microbial biotechnology.
TL;DR: This is the first report of flavone synthase I which had been considered to be restricted solely to species of the Apiaceae from a distant plantTaxon, and also three further activities assigned to flavonoid biosynthesis are identified.
TL;DR: Three new flavonoids, lawsochrysin (1), lawsonaringenin (2), and lawsonaredenin(3), were isolated from the leaves of Lawsonia alba Lam.
TL;DR: In this article, mild and environmentally benign methods for the synthesis of flavanones are described, where the reaction of o -hydroxyacetophenones and benzaldehydes in water in the presence of DABCO at room temperature gave 3-hydroxy-1-(2-hydroxylphenyl)-3-arylpropan-1-ones (3a -i ) as intermediates.
TL;DR: Flavonoids accumulated in proanthocyanidin-free near-isogenic lines iso ant 13, iso ant 17, and iso ant 22 of Nishinohoshi, developed by backcross breeding using a leading cultivar as a recurrent parent, were examined and the structures and stereochemistries of the isolated flavonoids were elucidated on the basis of spectroscopic analyses.
Abstract: Flavonoids accumulated in proanthocyanidin-free near-isogenic lines iso ant 13, iso ant 17, and iso ant 22 of Nishinohoshi, developed by backcross breeding using a leading cultivar, Nishinohoshi, as a recurrent parent and a proanthocyanidin-free mutant as a nonrecurrent parent in Japan, were examined. A new flavanone, (2RS)-dihydrotricin 7-O-β-D-glucopyranoside (1), known flavanones (2RS)-dihydrotricin (2) and (2RS)-homoeriodictyol (3), and known flavones chrysoeriol 7-O-[α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside] (4), chrysoeriol 7-O-β-D-glucopyranoside (5), tricin (6), and chrysoeriol (7) were isolated from iso ant 17 of Nishinohoshi. The structures and stereochemistries of the isolated flavonoids (1-7) were elucidated on the basis of spectroscopic analyses. The concentrations of the isolated flavonoids (1-7) in iso ant 13, iso ant 17, and iso ant 22 of Nishinohoshi were similar to each other, whereas the flavonoids 1-5 and 7 were not detected in Nishinohoshi, an old Japanese cultivar, Amaginijo, and North American cultivar Harrington. The concentration of tricin (6) in Nishinohoshi was a half those in iso ant 13, iso ant 17, and iso ant 22 of Nishinohoshi. Except for iso ant 13, iso ant 17, and iso ant 22 of Nishinohoshi, the concentration of tricin (6) was highest in Nishinohoshi, followed by Amaginijo and Harrington. Thus, tricin (6), its precursor dihydrotricin (2), and its glucopyranoside, dihydrotricin 7-O-β-D-glucopyranoside (1), as well as chrysoeriol (7) and homoeriodictyol (3) were accumulated in iso ant 13, iso ant 17, and iso ant 22 of Nishinohoshi probably by blocking at the step of flavanone 3-hydroxylase in the procyanidin biogenetic pathway, resulting in enhancement of the alternative biogenetic pathway.
TL;DR: Bifunctional cinchona alkaloids were used to catalyze a tandem intramolecular oxa-Michael addition/decarboxylation reaction of alkylidene β-ketoesters.
TL;DR: An efficient and green catalytic conversion of 2-hydroxychalcones to flavanones in 15 min in the presence of a simple amino acid and a base at room temperature is reported in this article.
Abstract: An efficient and “green” catalytic conversion of 2'-hydroxychalcones to flavanones in 15 min in the presence of a simple amino acid and a base at room temperature is reported. Liquiritigenin was al...
TL;DR: Three new prenylated flavanones were isolated from the n-hexane extract of Dalea boliviana roots and evaluated in vitro in relation to their inhibitory effect on the tyrosinase activity by using a spectrophotometric method.
Abstract: Three new prenylated flavanones, (2S)-5,7,2′-trihydroxy-5′-(1′′′,1′′′-dimethylallyl)-8-prenylflavanone (1), (2S)-5,7,2′-trihydroxy-8,3′-diprenylflavanone (2), and (2S)-5,2′-dihydroxy-6′′,6′′-dimethylchromeno-(7,8:2′′,3′′)-3′-prenylflavanone (3), and a known chromeno (dimethylpyrano) flavanone, obovatin (4), were isolated from the n-hexane extract of Dalea boliviana roots. The compounds were evaluated in vitro in relation to their inhibitory effect on the tyrosinase activity by using a spectrophotometric method.
TL;DR: Three antiproliferative compounds were isolated for the first time from Zeyheria montana and its leaves were characterized as an important source of methoxylated flavones and flavanone as potential antitumor compounds.
Abstract: The present study isolated three major active flavonoids, two flavones named 4’,5,7-trimethoxy-luteolin (1) and 6-hydroxy-5,7-dimethoxyflavone (2) and the flavanone 5-hydroxy-6,7-dimethoxyflavanone (3) from Zeyheria montana dichloromethane leaf extract. Isolation and purification were conducted with the application of column chromatography and structures were assigned by spectral analysis. All compounds were evaluated for cytotoxic activities against human tumor cell lines UACC-62 (melanoma), MCF-7 (breast), NCI-ADR/RES (breast expressing phenotype multiple drug resistance), 786-0 (renal), NCI-H460 (lung, non-small cells), PC-3 (prostate), OVCAR-3 (ovarian), HT-29 (colon) and K562 (leukemia) in vitro. All compounds were active in different degrees on several tumor cell lines and flavanone 3 showed cytotoxicity against almost all cell lines, particularly against human NCI-ADR/RES and K562 cell lines. In conclusion, three antiproliferative compounds were isolated for the first time from Zeyheria montana and its leaves were characterized as an important source of methoxylated flavones and flavanone as potential antitumor compounds. Copyright © 2011 John Wiley & Sons, Ltd.
TL;DR: An improved method of the synthesis of flavanones catalyzed by pyrrolidine and BF(3) ·Et(2) O has been developed and a lot of Flavanones could be easily synthesized via this method.
TL;DR: In this paper, the authors reported for the first time qualitative and quantitative data about flavonoids and furocoumarins distribution of unripe Citrus × myrtifolia Rafinesque homogenate, used as ingredient of the popular soft drink Chinotto.
Abstract: The present study reports for the first time qualitative and quantitative data about flavonoids and furocoumarins distribution of unripe Citrus × myrtifolia Rafinesque homogenate, used as ingredient of the popular soft drink Chinotto No data are available in literature about the chemical characterization of flavonoids and furocoumarins of the chinotto homogenate used to produce the industrial extract Samples for analysis were therefore processed to better reproduce the crude materials used to obtain industrial chinotto extract: the whole fruits were cut in half, seeds removed, softly squeezed discarding part of the juice, and homogenized in small pieces The polyphenolics separation was made by HPLC–PDA detector coupled to ESI/MS/MS in positive and negative mode It has allowed the identification and relative quantification of 16 compounds, among which the flavone-C-glycoside lucenin-2, the 3-hydroxy-3-methylglutaryl flavanone glycoside melitidin and five polymethoxylated flavones have been detected for the first time in Citrus × myrtifolia The flavonoids and furocoumarins distribution was compared with one of the Citrus × myrtifolia juice, and the antioxidant activity of both samples was assessed by ORAC (Oxygen Radical Absorbance Capacity)-fluorescein assay
01 Jan 2011
TL;DR: Biosynthesis of the core flavonoids and modification reactions resulting in the synthesis of flavonoid glycosides in Citrus are reviewed, with emphasis on Citrus flavonoidal glycosyltransferases.
Abstract: Citrus is one of the major crops in the world with notable consumption of fresh fruit and processed fruit products. Flavonoids and flavonoid glycosides in Citrus have an impact on consumer acceptance of fruit and fruit products as well as affecting human health. Glycosylation of flavonoids is a key modification process leading to the production of the compounds actually found in plant tissues. Citrus is known for synthesis and accumulation of significant levels of flavanone and flavone glycosides. Biosynthesis of the core flavonoids and modification reactions resulting in the synthesis of flavonoid glycosides in Citrus are reviewed, with emphasis on Citrus flavonoid glycosyltransferases.
TL;DR: Current research provides critical information on the role of centrifuge temperature, extraction solvent and their interactions on flavanone distribution in extracts.
TL;DR: The data presented here suggests, though does not conclude, that the rhizomes contain compounds possessing a range of antioxidant‐related properties, which may underpin the therapeutic, viz., anti‐inflammatory and adaptogenic effects, ascribed to species of this genus.
Abstract: Using spectrophotometric methods, a H(2) O-soluble Potentilla alba L rhizome extract was evaluated phytochemically, ie, the total phenol, flavonoid, flavonol, flavanone, and proanthocyanidin contents were determined, and its antioxidant and pro-oxidant properties, ie, the Fe(III) reductive and the Fe(II) chelating properties, the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH(*)), N,N-dimethyl-p-phenylenediamine (DMPD(*+)), and superoxide anion radical (O2*-)-scavenging activities, the capacity to inhibit hydroxyl radical (HO(*))-mediated deoxy-D-ribose and phospholipid degradation, and the interaction with the Cu-catalyzed HO(*) -mediated DNA degradation, were determined The extract was found to contain a range of phenolic compounds recognized to possess strong antioxidant-like properties Moreover, the extract demonstrated dose-dependent activities in all the antioxidant assays with the exception of the DNA-degradation assay, where the components within the extract interfered with the assay components at concentrations ≥100 mg/ml Potentilla species are known for their curative properties, with aerial/subterranean parts being prescribed for numerous indications The data presented here suggests, though does not conclude, that the rhizomes contain compounds possessing a range of antioxidant-related properties, which may underpin the therapeutic, viz, anti-inflammatory and adaptogenic effects, ascribed to species of this genus
TL;DR: In this paper, the best conditions for the preparation of flavanones and chromenes through this approach were explored, and the procedure is also an excellent way of preparing stereochemically pure Z aryl-alkenes.