Showing papers on "Flavanone published in 2019"
TL;DR: The protein binding rates of structurally different flavonoids to human serum albumin (HSA) were elucidated by applying the high performance affinity chromatography (HPAC) and it was found that an additional methoxy group in flavone ring A would decrease the protein binding rate.
55 citations
TL;DR: Twenty-six compounds were characterized as possessing an antiproliferative activity stronger than that of naringenin, and the replacement of the carbonyl group with an oxime moiety significantly increased the anticancer properties.
Abstract: In our investigation, we concentrated on naringenin (NG)—a widely studied flavanone that occurs in citrus fruits. As a result of a reaction with a range of alkyl iodides, 7 novel O-alkyl derivatives of naringenin (7a–11a, 13a, 17a) were obtained. Another chemical modification led to 9 oximes of O-alkyl naringenin derivatives (7b–13b, 16b–17b) that were never described before. The obtained compounds were evaluated for their potential antibacterial activity against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The results were reported as the standard minimal inhibitory concentration (MIC) values and compared with naringenin and its known O-alkyl derivatives. Compounds 4a, 10a, 12a, 14a, 4b, 10b, 11b, and 14b were described with MIC of 25 µg/mL or lower. The strongest bacteriostatic activity was observed for 7-O-butylnaringenin (12a) against S. aureus (MIC = 6.25 µg/mL). Moreover, the antitumor effect of flavonoids was examined on human colon cancer cell line HT-29. Twenty-six compounds were characterized as possessing an antiproliferative activity stronger than that of naringenin. The replacement of the carbonyl group with an oxime moiety significantly increased the anticancer properties. The IC50 values below 5 µg/mL were demonstrated for four oxime derivatives (8b, 11b, 13b and 16b).
36 citations
TL;DR: The results suggest that PpmyB15 and PpMYBF1 are functional flavonol-specific positive regulators in peach fruit and are important candidates for biotechnological engineering flav onol biosynthesis in plants.
Abstract: Flavonoids are major polyphenol compounds in plants and contribute substantially to the health-promoting benefits of fruit and vegetables. Peach is rich in polyphenols with flavonols as the main flavonoids. To investigate the regulation of flavonol biosynthesis in peach fruit, two R2R3-MYB transcription factor (TF) genes, PpMYB15 and PpMYBF1, were isolated and characterized. Sequence analysis revealed that the PpMYB15 and PpMYBF1 proteins are members of the flavonol clade of the R2R3-MYB family. Real-time quantitative PCR analysis showed that PpMYB15 and PpMYBF1 transcript levels correlated well with the flavonol content and the expression of flavonol synthase ( PpFLS1) in different fruit samples. Dual-luciferase assays indicated that both PpMYB15 and PpMYBF1 could trans-activate promoters of flavonoid biosynthesis genes, including chalcone synthase ( PpCHS1), chalcone isomerase ( PpCHI1), flavanone 3-hydroxylase ( PpF3H), and PpFLS1. Transient overexpression of 35S::PpMYB15 or 35S::PpMYBF1 both triggered flavonol biosynthesis but not anthocyanin and proanthocyanidin biosynthesis in tobacco leaves. In transgenic tobacco flowers, overexpression of 35S::PpMYB15 or 35S::PpMYBF1 caused a significant increase in flavonol levels and significantly reduced anthocyanin accumulation, resulting in pale-pink or pure white flowers. These results suggest that PpMYB15 and PpMYBF1 are functional flavonol-specific positive regulators in peach fruit and are important candidates for biotechnological engineering flavonol biosynthesis in plants.
36 citations
35 citations
TL;DR: Prenylated flavonoids have the potential to be developed as new drugs or supplements for human health, and it is reported that prenylation decreases the plasma absorption but increases the tissue accumulation.
Abstract: The genus Sophora (Fabaceae) has been used in traditional medicine for years. Prenylated flavonoids are one of the constituents of Sophora species that play important roles in their biological properties. Different classes of prenylated flavonoids are produced by Sophora spp. including prenylated flavonol (e.g., sophoflavescenol), prenylated flavanone (e.g., sophoraflavanone G), prenylated flavonostilbene (e.g., alopecurones A and B), and prenylated chalcone (kuraridin). Prenylated flavonoids have a more lipophilic structure, which leads to its high affinity to the cell membranes and enhancement of the biological activity, which includes cytotoxicity, antibacterial, anti-inflammatory, and estrogenic activities. However, it is reported that prenylation decreases the plasma absorption but increases the tissue accumulation. The presence of the prenyl or lavandulyl groups on C8 position of flavonoids plays an important role in the biological activity. It seems that prenylated flavonoids have the potential to be developed as new drugs or supplements for human health.
34 citations
TL;DR: In this work, the density functional theory methods were applied to investigate the influence of C2C3 double bond on the antiradical activity of flavonoid based on three prevalently accepted radical scavenging mechanisms from the thermodynamic aspect and it is found that the hydroxyl groups in different rings are affected variously by the C 2C3double bond.
33 citations
TL;DR: Phytochemical investigation of the root bark of U. davidiana var.
30 citations
TL;DR: Fcr is characterized as a key enzyme involved in the conversion of flavonoids of several subclasses by Eubacterium ramulus, a prevalent human gut bacterium, and a cofactor-mediated hydride transfer from NADH onto C-2 of the respective substrate is proposed.
Abstract: The human intestinal anaerobe Eubacterium ramulus is known for its ability to degrade various dietary flavonoids. In the present study, we demonstrate the cleavage of the heterocyclic C-ring of flavanones and flavanonols by an oxygen-sensitive NADH-dependent reductase, previously described as enoate reductase, from E. ramulus This flavanone- and flavanonol-cleaving reductase (Fcr) was purified following its heterologous expression in Escherichia coli and further characterized. Fcr cleaved the flavanones naringenin, eriodictyol, liquiritigenin, and homoeriodictyol. Moreover, the flavanonols taxifolin and dihydrokaempferol served as substrates. The catalyzed reactions were stereospecific for the (2R)-enantiomers of the flavanone substrates and for the (2S,3S)-configured flavanonols. The enantioenrichment of the nonconverted stereoisomers allowed for the determination of hitherto unknown flavanone racemization rates. Fcr formed the corresponding dihydrochalcones and hydroxydihydrochalcones in the course of an unusual reductive cleavage of cyclic ether bonds. Fcr did not convert members of other flavonoid subclasses, including flavones, flavonols, and chalcones, the latter indicating that the reaction does not involve a chalcone intermediate. This view is strongly supported by the observed enantiospecificity of Fcr. Cinnamic acids, which are typical substrates of bacterial enoate reductases, were also not reduced by Fcr. Based on the presence of binding motifs for dinucleotide cofactors and a 4Fe-4S cluster in the amino acid sequence of Fcr, a cofactor-mediated hydride transfer from NADH onto C-2 of the respective substrate is proposed.IMPORTANCE Gut bacteria play a crucial role in the metabolism of dietary flavonoids, thereby contributing to their activation or inactivation after ingestion by the human host. Thus, bacterial activities in the intestine may influence the beneficial health effects of these polyphenolic plant compounds. While an increasing number of flavonoid-converting gut bacterial species have been identified, knowledge of the responsible enzymes is still limited. Here, we characterized Fcr as a key enzyme involved in the conversion of flavonoids of several subclasses by Eubacterium ramulus, a prevalent human gut bacterium. Sequence similarity of this enzyme to hypothetical proteins from other flavonoid-degrading intestinal bacteria in databases suggests a more widespread occurrence of this enzyme. Functional characterization of gene products of human intestinal microbiota enables the assignment of metagenomic sequences to specific bacteria and, more importantly, to certain activities, which is a prerequisite for targeted modulation of gut microbial functionality.
24 citations
TL;DR: The flavonoid-rich products of B. papyrifera, including the new compounds, could be valuable candidates for the development of pharmaceuticals or functional foods in the prevention and treatment of anti-inflammatory disease.
24 citations
TL;DR: The result showed that a new flavanone, odoratenin, should be potential as an antioxidant source of C. odorata leaves, and exhibited very potent ABTS radical inhibitory activity.
Abstract: Chromolaena odorata L. (Asteraceae) is one of the tropical plants which is widely used as traditional medicines for diabetes and soft tissue wounds treatment in some regions in East Indonesia. The present study was aimed at determining the bioactive compounds of C. odorata leaves. The methanol and ethyl acetate extracts of C. odorata leaves have the inhibitory activity against 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals as well as α-glucosidase rat intestine enzyme. A new flavanone was isolated from the methanol extract and elucidated as 5,3'-dihydroxy-7,6'-dimethoxyflavanone or, namely, odoratenin (1) together with two known compounds: isosakuranetin (2) and subscandenin (3). The antioxidant activity of odoratenin (1) exhibited very potent ABTS radical inhibitory activity with IC50 value of 23.74 μM which is lower than that of trolox (IC50 31.32 μM) as a positive control. The result showed that a new flavanone, odoratenin (1), should be potential as an antioxidant source.
23 citations
TL;DR: Flavonoids from C. retusus flowers have significant potential as therapeutic materials in inflammation and neurodisease and were found to recover oxidative-stress-induced cell damage by increasing HO-1 protein expression.
Abstract: The dried flowers of Chionanthus retusus were extracted with 80% MeOH, and the concentrate was divided into EtOAc, n-BuOH, and H2O fractions. Repeated SiO2, octadecyl SiO2 (ODS), and Sephadex LH-20 column chromatography of the EtOAc fraction led to the isolation of four flavonols (1–4), three flavones (5–7), four flavanonols (8–11), and one flavanone (12), which were identified based on extensive analysis of various spectroscopic data. Flavonoids 4–6 and 8–11 were isolated from the flowers of C. retusus for the first time in this study. Flavonoids 1, 2, 5, 6, 8, and 10–12 significantly inhibited NO production in RAW 264.7 cells stimulated by lipopolysaccharide (LPS) and glutamate-induced cell toxicity and effectively increased HO-1 protein expression in mouse hippocampal HT22 cells. Flavonoids with significant neuroprotective activity were also found to recover oxidative-stress-induced cell damage by increasing HO-1 protein expression. This article demonstrates that flavonoids from C. retusus flowers have significant potential as therapeutic materials in inflammation and neurodisease.
TL;DR: A new aurone named (2Z)-2-[(4'-hydroxyphenyl) methylene]-6-hydroxy-7-prenyl-3(2H)-benzofurane, two new flavonoids, together with eleven known compounds, were isolated from the seeds of Psoralea corylifolia by spectroscopic and physico-chemical analyses.
TL;DR: In the course of studying the components from the roots of Sophora flavescens, eight new unusual biflavonoids consisting of a flavanone fused with a dihydrochalcone skeleton were isolated.
TL;DR: One new flavanonol, demethylmatteucinol (1), and nine new flavanone glucoside derivatives, matteflavosides H-J and matteuinterates A-F (5-10), were isolated from the rhizomes of Matteuccia intermedia C.Chr.
TL;DR: Results indicate that the process employed may influence the chemical composition and the functional properties of the ended juice, and that the screw press juice showed the highest antioxidant activity with EC50 value of 9.35 µg/mL, suggesting that this method maintains for health the nutritional quality of a fresh-pressed juice.
Abstract: Experimental and epidemiological studies show a positive relation between consumption of citrus juices and reduction of risk for some chronic disorders, such as diabetes and cardiovascular diseases. In particular, the bergamot juice is characterized by noticeable amounts of phytochemicals such as flavanone glycosides, limonoids, and quaternary ammonium compounds, all health-beneficial biomolecules. In vitro and in vivo studies have shown anti-inflammatory, cholesterol-lowering, and anti-diabetic activities attributed to these compounds depending on their chemical structure. However, nutritional content of bergamot juice may vary as consequence of different processing techniques, thus needing to address this claim. For this reason, the objective of this research was to evaluate the effects of different processing systems on the proximate constituents, the composition, and the antioxidant activity of the correspondent juices. Overall, the results indicate that the process employed may influence the chemical composition and the functional properties of the ended juice. Screw press method produced a juice with greater content of flavanone glycosides (ranged from 37 to 402 mg/L) and limonoid aglycones (ranged from 65 to 67 mg/L) than the other processes (p < 0.001). However, the process used for extraction of bergamot juice did not affect significantly the N,N-dimethyl-L-proline content (p < 0.5). Moreover, the screw press juice showed the highest antioxidant activity with EC50 value of 9.35 µg/mL, thus suggesting that this method maintains for health the nutritional quality of a fresh-pressed juice.
TL;DR: Four new chalcones, a new flavanone, (9), a new amide, (8), and 19 known compounds were acquired from Melodorum siamensis, and seven showed nuclear factor-κB inhibitory effects in a pancreatic β cell line (MIN-6 cells).
Abstract: Four new chalcones (1, 10, 13, and 14), a new flavanone, (9), a new amide (8), and 19 known compounds were acquired from Melodorum siamensis. The structures were established by NMR and MS data analyses. Compounds 1 (er 1.4:1) and 2 (er 1.1:1) were scalemic and were resolved to yield (-)-1 and (+)-1 and (-)-2 and (+)-2, respectively. The absolute configurations of these compounds were determined from experimental and calculated ECD data. The structures and configurations of (-)-2 and (+)-8 were identified by single-crystal X-ray diffraction analysis. Compound 11 showed nuclear factor-κB inhibitory effects (IC50 = 9 μM) in a pancreatic β cell line (MIN-6 cells).
TL;DR: Alopecurone J and P showed cytotoxic effect on MCF-7 cell line through Wnt signaling pathway and it seems that the presence of lavandulyl substitution in C-8 position of flavanone structure increased the cytot toxic effect.
TL;DR: Two new caffeoylquinic acid derivatives, a new flavanone glycoside, and six reported flavanones were isolated and identified from the flowers of C. morifolium and displayed neuroprotective effects against hydrogen peroxide-induced neurotoxicity in human neuroblastoma SH-SY5Y cells.
Abstract: The Chrysanthemum morifolium flower is widely used in China and Japan as a food, beverage, and medicine for many diseases. In our work, two new caffeoylquinic acid derivatives (1, 2), a new flavanone glycoside (3), and six reported flavanones (4⁻9) were isolated and identified from the flowers of C. morifolium. The chemical structures of all isolates were elucidated by the analysis of comprehensive spectroscopic data as well as by comparison with previously reported data. The isolated constituents 1⁻8 were evaluated for their neuroprotective activity, and compounds 3 and 4 displayed neuroprotective effects against hydrogen peroxide-induced neurotoxicity in human neuroblastoma SH-SY5Y cells.
TL;DR: Results indicate that CYP2A6 and other human P450s have important roles in metabolizing flavone and flavanone, two unsubstituted flavonoids, present in dietary foods.
Abstract: 1. We previously reported that flavone and flavanone interact spectrally with cytochrome P450 (P450 or CYP) 2A6 and 2A13 and other human P450s and inhibit catalytic activities of these P450 enzymes...
TL;DR: In vitro enzymatic assays indicated OcFLS1 and OCFLS2 were flavonol synthases, catalysing the conversion of dihydroflavonols to flavonols in an iron-dependent fashion, and the qRT-PCR analysis demonstrated that both genes were expressed in the leaves, bulbs, and flowers, with particularly high expression in the Leaves.
Abstract: Flavonol synthase (FLS) is the key enzyme responsible for the biosynthesis of flavonols, the most abundant flavonoids, which have diverse pharmaceutical effects. Flavonol synthase has been previously found in other species, but not yet in Ornithogalum caudatum. The transcriptome-wide mining and functional characterisation of a flavonol synthase gene family from O. caudatum were reported. Specifically, a small FLS gene family harbouring two members, OcFLS1 and OcFLS2, was isolated from O. caudatum based on transcriptome-wide mining. Phylogenetic analysis suggested that the two proteins showed the closest relationship with FLS proteins. In vitro enzymatic assays indicated OcFLS1 and OcFLS2 were flavonol synthases, catalysing the conversion of dihydroflavonols to flavonols in an iron-dependent fashion. In addition, the two proteins were found to display flavanone 3β-hydroxylase (F3H) activity, hydroxylating flavanones to form dihydroflavonols. Unlike single F3H enzymes, the F3H activity of OcFLS1 and OcFLS2 did not absolutely require iron. However, the presence of sufficient Fe2+ was demonstrated to be conducive to successive catalysis of flavanones to flavonols. The qRT-PCR analysis demonstrated that both genes were expressed in the leaves, bulbs, and flowers, with particularly high expression in the leaves. Moreover, their expression was regulated by developmental and environmental conditions. OcFLS1 and OcFLS2 from O. caudatum were demonstrated to be flavonol synthases with iron-independent flavanone 3-hydroxylase activity.
TL;DR: Differences in the physicochemical properties of the four flavanones are demonstrated and structure–activity relationships observed for antioxidant activity and DNA interactions suggest that 6-hydroxyflavanone can protect DNA against oxidative damage most effectively than flavanone, 2′-HydroxyFlavanone or 7-hydroxflavan one.
Abstract: Structure-related biological activities of flavanones are still considered largely unexplored. Since they exhibit various medicinal activities, it is intriguing to enter deeper into their chemical structures, electronic transitions or interactions with some biomolecules in order to find properties that allow us to better understand their effects. Little information is available on biological activity of flavanone and its monohydroxy derivatives in relation to their physicochemical properties as spectral profiles, existence of protonated/deprotonated species under pH changes or interaction with Calf Thymus DNA. We devoted this work to research demonstrating differences in the physicochemical properties of the four flavanones: flavanone, 2'-hydroxyflavanone, 6-hydroxyflavanone and 7-hydroxyflavanone and linking them to their biological activity. Potentiometric titration, UV-Vis spectroscopy were used to investigate influence of pH on acid-base and spectral profiles and to propose the mode of interaction with DNA. Cyclic voltammetry was applied to evaluate antioxidant potentiality and additionally, theoretical DFT(B3LYP) method to disclose electronic structure and properties of the compounds. Molecular geometries, proton affinities and pKa values have been determined. According to computational and cyclic voltammetry results we could predict higher antioxidant activity of 6-hydroxyflavanone with respect to other compounds. The values of Kb intrinsic binding constants of the flavanones indicated weak interactions with DNA. Structure-activity relationships observed for antioxidant activity and DNA interactions suggest that 6-hydroxyflavanone can protect DNA against oxidative damage most effectively than flavanone, 2'-hydroxyflavanone or 7-hydroxyflavanone.
TL;DR: It is suggested that CYP2A6 catalyzes site-specific oxidation of (racemic) flavanone and also flavone in human liver microsomes by playing significant roles in some of the oxidations of these flavonoids by human livermicrosomes.
Abstract: The roles of human cytochrome P450 (P450 or CYP) 2A6 in the oxidation of flavanone [(2R)- and (2S)-enantiomers] and flavone were studied in human liver microsomes and recombinant human P450 enzymes. CYP2A6 was highly active in oxidizing flavanone to form flavone, 2'-hydroxy-, 4'-, and 6-hydroxyflavanones and in oxidizing flavone to form mono- and di-hydroxylated products, such as mono-hydroxy flavones M6, M7, and M11 and di-hydroxy flavones M3, M4, and M5. Liver microsomes prepared from human sample HH2, defective in coumarin 7-hydroxylation activity, were very inefficient in forming 2'-hydroxyflavanone from flavanone and a mono-hydroxylated product, M6, from flavone. Coumarin and anti-CYP2A6 antibodies strongly inhibited the formation of these metabolites in microsomes prepared from liver samples HH47 and 54, which were active in coumarin oxidation activities. Molecular docking analysis showed that the C2'-position of (2R)-flavanone (3.8 A) was closer to the iron center of CYP2A6 than the C6-position (10 A), while distances from C2' and C6 of (2S)-flavanone to the CYP2A6 were 6.91 A and 5.42 A, respectively. These results suggest that CYP2A6 catalyzes site-specific oxidation of (racemic) flavanone and also flavone in human liver microsomes. CYP1A2 and CYP2B6 were also found to play significant roles in some of the oxidations of these flavonoids by human liver microsomes.
TL;DR: It is shown that many species of Eucalyptus are abundant sources of promising medicinal flavanones, and selection of high-yielding species and genotypes for growth-rate assessment trials and the future establishment of commercial plantations is shown.
TL;DR: Alcoholic leaf extract ameliorated the MTX-induced alterations by improving several biochemical marker levels, fighting oxidative stress in serum and liver tissues, and decreasing inflammatory mediators; this finding was further confirmed by the histopathological study.
TL;DR: These five compounds (1–5) were isolated from the family Boraginaceae for the first time and anti-inflammatory effects of compounds were evaluated in terms of inhibition of production of NO, TNF-α, and IL-6 in LPS-induced RAW 264.7 cells.
TL;DR: A general protocol for direct glucuronic linkages formation featuring Au(I)-catalyzed appropriately protected glucuronyl o-alkynylbenzoate-involved glycosylation reaction, and a novel route for scutellarin derivatives preparation has been devised, guarantee the high whole synthetic efficiency.
TL;DR: This study is the first to systematically investigate the role of the structure of the flavonoid C-ring across a full set of flavonoids with identical B-rings.
TL;DR: All the isolated flavone and flavonol derivatives showed moderate effects against B. caballi and/or T. equi, and most of the isolated chalcone and flavanone derivatives did not show any anti-piroplasm activity.
Abstract: Pulsatilla species are known as "Yargui", and their flowers are traditionally used in Mongolia as a tonic and for the treatment of inflammatory diseases. By chemical investigation of P. flavescens flowers, 21 flavonoids, including a new chalcone C-glucoside, chalconaringenin 2'-O-β-D-glucopyranosyl-5'-β-D-glucopyranoside, and two new flavanone C-glucosides, (2R)- and (2S)-naringenin 8-β-D-glucopyranosyl-4'-O-β-D-glucopyranoside, were isolated. The absolute configurations of the seven flavanone glucosides were elucidated by ECD spectra. For the isolated compounds, inhibitory activity against Babesia caballi and Theileria equi, which cause fatal diseases in horses, was estimated. Although most of the isolated chalcone and flavanone derivatives did not show any anti-piroplasm activity, all the isolated flavone and flavonol derivatives showed moderate effects against B. caballi and/or T. equi.
TL;DR: The comparison of the pharmacokinetic parameters of flavanone glycosides showed that the absorption of AF extract was lower, while the elimination was relatively rapid, compared with those of AFI extract, which may be useful for further utilization of these two citrus herbs.
Abstract: Background: Aurantii Fructus Immaturus (AFI) and Aurantii Fructus (AF) are two traditional citrus herbs with health-promoting and nutritive properties. Objective: This paper presents the first attempt to simultaneously investigate the absorption of five major flavanone glycosides, namely narirutin, naringin, hesperidin, neohesperidin, and poncirin, in rat plasma following a single oral administration of AFI and AF extracts to rats. Methods: The plasma concentrations were determined by liquid-liquid extraction followed by a rapid and sensitive ultra-performance LC-tandem mass spectrometry method. Pharmacokinetic parameters were analyzed by noncompartmental modeling using DAS software. Results: The developed method was validated and successfully applied to the pharmacokinetic study of these five flavanone glycosides. Conclusions: The comparison of the pharmacokinetic parameters of flavanone glycosides showed that the absorption of AF extract was lower, while the elimination was relatively rapid, compared with those of AFI extract. Highlights: This study may be useful for further utilization of these two citrus herbs.