Showing papers on "Flavanone published in 2018"

Identification and Characterization of Flavonoid Biosynthetic Enzyme Genes in Salvia miltiorrhiza (Lamiaceae)

Abstract: Flavonoids are a class of important secondary metabolites with a broad spectrum of pharmacological functions. Salviamiltiorrhiza Bunge (Danshen) is a well-known traditional Chinese medicinal herb with a broad diversity of flavonoids. However, flavonoid biosynthetic enzyme genes have not been systematically and comprehensively analyzed in S.miltiorrhiza. Through genome-wide prediction and molecular cloning, twenty six flavonoid biosynthesis-related gene candidates were identified, of which twenty are novel. They belong to nine families potentially encoding chalcone synthase (CHS), chalcone isomerase (CHI), flavone synthase (FNS), flavanone 3-hydroxylase (F3H), flavonoid 3'-hydroxylase (F3'H), flavonoid 3',5'-hydroxylase (F3'5'H), flavonol synthase (FLS), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS), respectively. Analysis of intron/exon structures, features of deduced proteins and phylogenetic relationships revealed the conservation and divergence of S.miltiorrhiza flavonoid biosynthesis-related proteins and their homologs from other plant species. These genes showed tissue-specific expression patterns and differentially responded to MeJA treatment. Through comprehensive and systematic analysis, fourteen genes most likely to encode flavonoid biosynthetic enzymes were identified. The results provide valuable information for understanding the biosynthetic pathway of flavonoids in medicinal plants.

Indirect and direct routes to C-glycosylated flavones in Saccharomyces cerevisiae

Abstract: C-glycosylated flavones have recently attracted increased attention due to their possible benefits in human health. These biologically active compounds are part of the human diet, and the C-linkage makes them more resistant to hydrolysis and degradation than O-glycosides. In contrast to O-glycosyltransferases, few C-glycosyltransferases (CGTs) have so far been characterized. Two different biosynthetic routes for C-glycosylated flavones have been identified in plants. Depending on the type of C-glycosyltransferase, flavones can be glycosylated either directly or indirectly via C-glycosylation of a 2-hydroxyflavanone intermediate formed by a flavanone 2-hydroxylase (F2H). In this study, we reconstructed the pathways in the yeast Saccharomyces cerevisiae, to produce some relevant CGT substrates, either the flavanones naringenin and eriodictyol or the flavones apigenin and luteolin. We then demonstrated two-step indirect glycosylation using combinations of F2H and CGT, to convert 2-hydroxyflavanone intermediates into the 6C-glucoside flavones isovitexin and isoorientin, and the 8C-glucoside flavones vitexin and orientin. Furthermore, we established direct glycosylation of flavones using the recently identified GtUF6CGT1 from Gentiana triflora. The ratio between 6C and 8C glycosylation depended on the CGT used. The indirect route resulted in mixtures, similar to what has been reported for in vitro experiments. In this case, hydroxylation at the flavonoid 3′-position shifted the ratio towards the 8C-glucosylated orientin. The direct flavone glycosylation by GtUF6CGT1, on the other hand, resulted exclusively in 6C-glucosides. The current study features yeast as a promising host for production of flavone C-glycosides, and it provides a set of tools and strains for identifying and studying CGTs and their mechanisms of C-glycosylation.

Flavonoids, a Potential New Insight of Leucaena leucocephala Foliage in Ruminant Health.

Abstract: We investigated the constituents of Leucaena leucocephala foliage collected from Guangdong province in China and isolated 17 diverse flavonoids (1-17), including flavones (5-9, 11, and 12), flavonols (1, 10, and 16), flavanone 4, flavanonol 15, and flavonol glycosides (2, 3, 13, 14, and 17). Flavonoids quercetin (1), quercetin-3- O-α-rhamnopyranoside (2), and myricetin-3- O-α-rhamnopyranoside (17) were the major flavonoids components in L. leucocephala leaves, at a total concentration of about 2.5% of dry matter. pHRE-Luc inductive activity to mimic the activation of erythropoietin (EPO) gene, anti-inflammatory, antidiabetic, and antioxidant activities of isolated flavonoids (1-17) were evaluated. Flavonoids 7, 10, and 13 could strongly induce the transcriptional activity of pHRE-Luc, which indicated their potential to induce the expression of EPO. Flavonoids 7, 10, 13, and 17 displayed strong anti-inflammatory activity, relatively equal to the positive control dexamethasone. Flavonoids 1, 2, 3, 11, 12, 16, and 17 showed stronger antioxidant activities of DPPH radical scavenging capacity than ascorbic acid. Flavonoids 1, 2, and 10 showed weak cellular antioxidant activities against tert-butyl hydroperoxide (tBHP) induced ROS formation. Flavonoid rhamnoside 2 and arabinoside 3 undergone deglycosylation to the aglycone quercetin under anaerobic incubation with cattle rumen microorganisms. Furthermore, the potential health benefits for ruminant of flavonoids, which was rich in L. leucocephala foliage, was also discussed.

Phenolic profiling and quantitative determination of common sage (Salvia plebeia R. Br.) by UPLC-DAD-QTOF/MS

Abstract: Salvia plebeia R. Br. is a medicinal herb that contains important active compounds such as flavonoid and phenolic acid which are responsible for remarkable biological properties. The phenolic composition of S. plebeia was quantitatively investigated using ultra-performance liquid chromatograph coupled with photodiode array detection and quadrupole time of flight mass spectrometry. A total of 16 flavonoids were classified into 10 flavones and 6 flavanones based on UV-spectra and ion fragmentation patterns. Individual flavonoids, including apigenin, luteolin, hispidulin, nepetin, and some flavanones, were glycosylated with glucose at the 5- or 7-position of flavonoid structure. The three major flavones were determined to be 6-hydroxyluteolin 7-O-glucoside [2,452.7 mg/100 g dry weight (DW)], hispidulin 7-O-glucoside (2,281.0 mg/100 g DW) and nepetin 7-O-glucoside (2,002.6 mg/100 g DW). The six flavanones containing the hydroxyl and methoxy groups were determined and, among them, 5,7,3′,4′- tetrahydroxy-6-methoxyflavanone 7-O-glucoside have the highest level (938.3 mg/100 g DW). Two hydroxyl flavanone glycosides, 5,6,7,3′,4′- pentahydroxyflavanone 7-O-glucoside and 5,6,7,4′- tetrahydroxyflavanone 7-O-glucoside, were presumed to be newly identified compounds, on the basis of the library data from S. plebeia. In addition, higher concentration of rosmarinic acid was also identified.

Chemical studies on the parasitic plant Thonningia sanguinea Vahl

Abstract: Thonningia sanguinea Vahl plays an important role in traditional medicine in many African cultures. A study of the n-hexane fraction of the whole plant of T. sanguinea led to the isolation of two glucocerebroside molecular species TSC-1 and TSC-2, one β-sitosteryl-3β-D-glucopyranoside-6′-O-fatty acid ester molecular species, TSS-1, and seven known triterpenes (1–7). The ethyl acetate fraction also afforded five known lignans (8–12) and one known flavanone (13). Their structures were elucidated by means of chemical and spectroscopic methods (methanolysis, NMR and mass spectrometry). Spectral analyses of the glucocerebrosides revealed mainly sphingosine-type (TSC-1) and phytosphingosine-type (TSC-2) cerebrosides, with both possessing mainly 2-hydroxy fatty acid and β-D-glucopyranose moieties. TSS-1 was found to be a β-sitosterol-type with fatty acid methyl esters and β-D-glucopyranoside moieties. The classes of compounds isolated from this plant are well known for their interesting biological activities including antimicrobial, antioxidant, anticancer, antiinflammatory and analgesic. They may therefore be responsible in part or in whole for these activities, hence validating the traditional uses of the plant. To the best of our knowledge, this is the first report on the isolation of all these compounds from T. sanguinea.

The Major Flavonoid of Grapefruit: Naringin

Abstract: Naringin is the predominant flavanone found in citrus fruits. Several biological properties of naringin such as antioxidant, antiinflammatory, and anticancer activities were reported but also some studies demonstrated that naringin caused side effects and interactions with drugs. This chapter aims to provide knowledge and general information about naringin and its effects on human health.

Studies on the UV filtering and radical scavenging capacity of the bitter masking flavanone Eriodictyol

Abstract: A computational analysis of UV filtering and radical scavenging capacity of a flavanone, Eriodictyol has been performed under DFT-B3LYP/6–31+ G (d, p). Eriodictyol is nontoxic and nonirritant bitter masker commonly used in the wine industry. It has been reported that the flavanones were widely acceptable for photoprotection due to its potential UV filtering and radical scavenging capacity. This study provides theoretical evidence that the eriodictyol has an absorbance in the UV-A and UV-B region of the electromagnetic spectrum and therefore can be used as a potential UV filter in sunscreen lotions and other cosmetic products. The major transitions in the UV–Visible spectrum of Eriodictyol are between HOMO and HOMO-1 with LUMO level and are well explained by NBO-NLMO tool in G09 software. In addition to this, Eriodictyol is a potent antioxidant than that of the most commonly studied Quercetin. The most active site in the compound is 3′ position and is confirmed by NPA, NBO and pKa value analysis. The lowest energy conformer of Eriodictyol contains a Hydrogen bond between carbonyl oxygen (O2) and H30. This is confirmed by the highest value of interaction energy between lone pairs of O2 and σ* of O3– H30. Both the two lone pairs of O2 interacts with the σ* of O3-H30. This decreases the bond order of 5 OH and at the same time it restricts the hydrogen transfer from this position to form a radical. Similarly, the lone pair of O5 (3′ position) interacts with H33 resulting in the low bond order value and consequently less favorable for radical formation. These results indicate that the BDE values follow the order 3′

Convenient Synthesis and Physiological Activities of Flavonoids in Coreopsis lanceolata L. Petals and Their Related Compounds

Abstract: Chalcones, flavanones, and flavonols, including 8-methoxybutin isolated from Coreopsis lanceolata L petals, were successfully synthesized with total yields of 2⁻59% from O-methylpyrogallols using the Horner⁻Wadsworth⁻Emmons reaction as a key reaction Aurones, including leptosidin, were also successfully synthesized with 5⁻36% total yields using the Aldol condensation reaction as a key reaction Each chalcone, flavanone, flavonol, and aurone with the 3,4-dihydroxy groups in the B-ring showed high antioxidant activity Additionally, each of the chalcones, flavanones, flavonols, and aurones with the 2,4-dihydroxy groups in the B-ring showed an excellent whitening ability

Enzymatic production of natural sweetener trilobatin from citrus flavanone naringin using immobilised α-l-rhamnosidase as the catalyst

Abstract: 1 School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China 2 Goldenpomelo Biotechnology Co. Ltd., Meizhou 514021, China 3 School of Chemical and Environmental Engineering, International Healthcare Innovation Institute (Jiangmen), Wuyi University, Jiangmen 529020, China 4 Centre for Education in Environmental Sustainability, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, Hong Kong, China

Comparative study of total phenolic compounds, flavonoids and antioxidant capacities in pigmented and non-pigmented rice of indica rice varieties

Abstract: The total phenolic compounds and flavonoid contents of grains as well as the antioxidant capacities were determined in 15 rice varieties. A high-performance liquid chromatography method was modified for the determination of the flavonoid subgroups in rice grains. The results showed the total phenolic compounds, flavonoid contents, and antioxidant capacities of pigmented rice were higher than in non-pigmented rice. The amounts of flavanone groups ranging from 0.04 to 0.40 mg Naringenin g−1, while flavones groups ranging from 0.08 to 0.57 mg Apigenin g−1, flavonol groups ranging from 0.16 to 1.20 mg Quercetin g−1 and anthocyanin groups ranging from 44.43 to 69.83 mg Cyanidin chloride g−1 were found in pigmented rice. The total phenolic compounds and total flavonoid contents of grains were significantly correlated with their antioxidant capacities. The results indicated that pigmented rice appeared as a good source of phenolic and flavonoid compounds and had beneficial nutritive values or antioxidant substances.

Preparation, characterization and in vitro and in vivo evaluation of a solid dispersion of Naringin.

Abstract: Naringin (NA) is one of typical flavanone glycosides widely distributed in nature and possesses several biological activities including antioxidant, anti-inflammatory, and antiapoptotic. The aim of...

Chromatographic and spectroscopic studies on β-cyclodextrin functionalized ionic liquid as chiral stationary phase: Enantioseparation of NSAIDs:

Abstract: In this study, β-cyclodextrin functionalized ionic liquid was prepared by adding 1-benzylimidazole onto 6-monotosyl-6-deoxy-β-cyclodextrin (β-CDOTs) to obtain β-CD-BIMOTs. β-CD-BIMOTs were then bonded onto the modified silica to produce chiral stationary phases (β-CD-BIMOTs-CSP). The performance of β-CD-BIMOTs-CSP was evaluated by observing the enantioseparation of flavonoids. The performance of β-CD-BIMOTs stationary phase was also compared with native β-CD stationary phase. For the selected flavonoids, flavanone and hesperetin obtained a high resolution factor in reverse phase mode. Meanwhile, naringenin and eriodictyol attained partial enantioseparation in polar organic mode. In order to understand the mechanism of separation, the interaction of selected flavonoids and β-CD-BIMOTs was studied using spectroscopic methods (1H NMR, NOESY and UV–Vis spectrophotometry). The enantioseparated flavanone and hesperetin were found to form an inclusion complex with β-CD-BIMOTs. However, naringenin and eriodictyol were not enantioseparated due to the formation of hydrogen bonding at exterior torus of β-CD-BIMOTs.

Catalytic and stoichiometric flavanone oxidation mediated by nonheme oxoiron(iv) complexes as flavone synthase mimics: kinetic, mechanistic and computational studies.

Abstract: The present study describes the first example of the stoichiometric and catalytic oxidation of flavanone by synthetic nonheme oxoiron(iv) complexes and their precursor iron(ii) complexes with m-CPBA as the terminal oxidant These models, including detailed kinetic, mechanistic and computational studies, may serve as the biomimics of flavone synthase (FS) enzymes

Antiviral Activity of Faramea hyacinthina and Faramea truncata Leaves on Dengue Virus Type-2 and Their Major Compounds.

Abstract: The defatted fractions of the Faramea hyacinthina and F. truncata (Rubiaceae) leaf MeOH extracts showed in vitro non-cytotoxic and anti-dengue virus serotype 2 (DENV2) activity in human hepatocarcinoma cell lineage (HepG2). Submitting these fractions to the developed RP-SPE method allowed isolating the antiviral flavanone (2S)-isosakuranetin-7-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (1) from both species and yielded less active sub-fractions. The new diastereoisomeric epimer pair (2S) + (2R) of 5,3',5'-trihydroxyflavanone-7-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (2a/2b) from F. hyacinthina; the known narigenin-7-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (3) from both species; rutin (4) and quercetin-4'-β-d-O-glucopyranosyl-3-O-rutinoside (5) from F. hyacinthina, and kaempferol-3-O-rutinoside (6), erythroxyloside A (7) and asperuloside (8) from F. truncata have been isolated from these sub-fractions. Compounds 4 - 8 are reported for the first time in Faramea spp.

Structure–activity relationships of flavanones, flavanone glycosides, and flavones in anti-degranulation activity in rat basophilic leukemia RBL-2H3 cells

Abstract: The incidence of type I allergies, which are associated with mast cell degranulation and local inflammation, is increasing, and new treatments are needed To date, structure–activity relationships of flavonoids in their degranulation-inhibiting activity have not been systematically characterized In the current study, the degranulation-inhibiting activity of a series of flavonoids was evaluated The following three observations were made: (1) the activity disappears when a sugar moiety is introduced into the A ring of the flavanone; (2) the activity depends on the number of hydroxyl groups on the B ring; (3) the activity is markedly enhanced when a double bond is introduced into the C ring The information obtained in the current study may guide the development of a therapy for type I allergies

Wood photostabilization roles of the condensed tannins and flavonoids from the EtOAc fraction in the heartwood extract of Acacia confusa

Abstract: Lignin, one of the three major components in wood, can absorb UV light and react with 1O2, leading to wood photodegradation. Previous studies demonstrated the ethyl acetate (EtOAc) fraction of the heartwood extract in Acacia confusa (AcHW) has good photostabilities to prevent photodegradation of the wood. However, these effective constituents have different structural characteristics and may affect their photostabilities and protection efficacies on wood which need to be clarified. This study analyzed the polyphenolic contents, chemical constituents and photostabilities of the six subfractions (EA1–EA6) which successively fractioned from the EtOAc fraction in AcHW by the colorimetric methods, UV/Vis spectrophotometry and high-performance liquid chromatography and evaluated the wood photoprotection abilities of these treatments. The results showed the more flavones and flavonols contained in the subfractions, the better the UVA absorptivity was. Besides, the catecholic-condensed tannins and flavonoids in these subfractions also provide good 1O2 quenching abilities and phenoxyl radical scavenging abilities. Advanced results also established in these subfractions, melanoxetin, transilitin, 7,3′,4′-trihydroxy-3-methoxyflavone, 7,8,3′-trihydroxy-3,4′-dimethoxyflavone (flavonols), 7,8,3′,4′-tetrahydroxyflavone, 7,3′,4′-trihydroxyflavone, 7,3′,4′-trihydroxy-5-methoxyflavone (flavones) and okanin (chalcone) can absorb the energy of UVA light; the condensed tannins, 3,4-dihydroxybenzoic acid (phenolic acid), melacacidin-based oligomers, melacacidin, 4-O-methylmelacacidin, 4′-O-methylmelacacidin (melacacidin-based flavanols), 3,7,8,3′,4′-pentahydroxyflavanone (flavanonol), 7,8,3′,4′-tetrahydroxyflavanone (flavanone), the flavones, flavonols and chalcone can suppress the phenoxyl radicals; the condensed tannins, melacacidin-based oligomers and the flavonoids can quench 1O2. Hence, the photostability of extract-free wood slices treated with these effective constituents was consequently enhanced. In summary, these results clearly demonstrated the multiple wood photoprotection actions of these effective constituents and their potential as natural wood photostabilizers.

A New Flavanone from Spatholobus Suberectus Dunn

Abstract: A new flavanone, namely 2-(S)-6,7,3’,5′-tetrahydroxyflavanone, was separated from the ethanol extracts of the dried vine stems of Spatholobus suberectus dunn, together with three known ones, 2-(S)-...

Synthesis of Chalcone and Flavanone Derivatives using ZnO Nanoparticle as Catalyst for Antibacterial Activity

Abstract: A green method was developed for the synthesis of chalcone and flavanone derivatives by Claisen-Schmidth reaction using ZnO nanoparticles as catalyst and water as solvent. The yield of flavonone synthesis reaction catalyzed by ZnO Nanoparticles was found to be higher (89.6%) compared to conventionally protocol (55.7 %) catalyzed by KOH. In vitro antibacterial activity of the synthesized compounds against the Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli , P. aeruginosa and K. preumanin revealed that chalcones 4 and 5 are active on against S. aureus (13 and 11 mm zone of inhibition, respectively) whereas flavonones 6 showed promising activity against E. coli (10 mm zone of inhibition) and chalcone 5 against S. aureus and P.aeroginosa (10 mm zone of inhibition for each) compared to Ceftraxione as positive control. Keywords : Chalcones, flavanone, Green synthesis, ZnO nanoparticles.

Isolation of 5,7-Dihydroxy, 6,8-Dimethyl Flavanone from Syzygium aqueum with Its Antioxidant and Xanthine Oxidase Inhibitor Activities.

Abstract: Background: Syzygium aqueum Burm.f. Alston (water apple) belonging to Myrtaceae family was originated from tropical areas. It was traditionally used as a medicinal plant. Objective: The objective of the study was to isolate the active compound from the methanolic extract of S. aqueum leaves. Methods: Extraction was done using continuous extraction with methanol as a solvent. The extract was then fractionated using liquid–liquid extraction, vacuum liquid chromatography, and radial chromatography. Recrystallization was done for purification. The structure of the compound was determined by Ultraviolet-Visible and (1D and 2D) nuclear magnetic resonance (NMR) spectrometer. Results: The isolate showed maximum wavelengths at 347 (band I) and 296 (band II) nm. After addition of NaOH and CH3COONa, the maximum wavelengths of band II moved to 340 and 339 nm, respectively. There was no change in wavelengths after addition CH3COONa/H3BO3and AlCl3. The1H-NMR spectrum showed 16 protons, whereas13C-NMR spectrum showed 15 carbons. Based on those data, the isolate was determined as 5,7-dihydroxy-6,8-dimethyl flavanone (demethoxymatteucinol). At a concentration of 100 and 50 μg/mL, it could inhibit 25.13% of xanthine oxidase (XO) activity and scavenge 11.87% of diphenyl-picrylhydrazyl, respectively. Conclusion: Demethoxymatteucinol was isolated for the first time from S. aqueum and it had mild antioxidant and XO inhibitory activities.

Phytochemical investigation of the medicinal plant moricandia arvensis l. from algerian sahara

Abstract: Objective: The aim of this research was to isolate and identify flavonoids extracted from the leaves of Moricandia arvensis . Methods: The phytochemical screening reaction and thin-layer chromatography have been used to characterize the chemical groups, before they were identified by nuclear magnetic resonance. Results: The leaves contain essentially flavonoids, tannins, cardenolides, saponins, and alkaloids. The phytochemical investigation of the water-acetone extract led to the isolation of five flavonoids derivatives, namely: 5,7-dihydroxy-3,6,4’-trimethoxyflavone (1); 5,7,4’-trihydroxy- 3,6,8,3’-tetramethoxyflavone (2); 3,3’,4’, 5,7- pentahydroxy flavanone (3); 3-glucosyl 3’,4’,5,7 tetrahydroxy flavonol (4); and kaempferol-3- digalactopyranoside (5). The structures of 1–5 were identified by comparison of their spectral data with those reported in the literature. Conclusion: In this work, it was possible to isolate and identify five flavonoids after fractionation of the hydroacetone extract from the leaves of the medicinal plant M. arvensis .