Functional analysis of flavanone 3-hydroxylase(F3H)from Dendrobium officinale,which confers abiotic stress tolerance

Flavonoids are important bioactive components in Dendrobium officinale,a medicinal orchid.They are involved in many biological activities,including protecting plants against biotic and abiotic stresses.Research on the key genes related to flavonoid biosynthesis in D.officinale is limited.In this study,one of the key flavonoid biosynthesis genes,flavanone 3-hydroxylase(F3H),was characterized from D.officinale.The open reading frame of DoF3H was 1134 bp long and it encoded a 377-amino acid protein.The DoF3H protein showed considerably high homology with F3H proteins from other plant species and shared a common evolutionary ancestor with other F3Hs.DoF3H transcripts were detected in different organs of adult plants and mainly accumulated in flowers,followed by roots,stems and leaves,a pattern that was similar to the content of flavonoids.Recombinant DoF3H protein,which was localized in the cytosol,could convert naringenin to dihydrokaempferol.The mRNA levels of DoF3H were significantly induced by salt and cold stresses.Furthermore,the heterologous expression of DoF3H in Escherichia coli conferred it higher tolerance to salt and cold stresses.These results provide insight into the molecular function of DoF3H in the biosynthesis of flavonoids,and provide a new application for improvement of abiotic tolerance in D.officinale.

Flavanone and flavonoid hydroxylase genes regulate fiber color formation in naturally colored cotton

Using naturally colored cotton(NCC)can eliminate dyeing,printing and industrial processing,and reduce sewage discharge and energy consumption.Proanthocyanidins(PAs),the primary coloration components in brown fibers,are polyphenols formed by oligomers or polymers of flavan-3-ol units derived from anthocyanidins.Three essential structural genes for flavanone and flavonoid hydroxylation encoding flavanone-3-hydroxylase(F3H),flavonoid 3’-hydroxylase(F3’H)and flavonoid 3’5’-hydroxylase(F3’5’H)are initially committed in the flavonoid biosynthesis pathway to produce common precursors.The three genes were all expressed predominantly in developing fibers of NCCs,and their expression patterns varied temporally and spatially among NCC varieties.In GhF3Hi,GhF3’Hi and GhF3’5’Hi silenced lines of NCC varieties XC20 and ZX1,the expression level of the three genes decreased in developing cotton fiber,negatively correlated with anthocyanidin content and fiber color depth.Fiber color depth and type in RNAi lines changed with endogenous gene silencing efficiency and expression pattern,the three hydroxylase genes functioned in fiber color formation.GhF3H showed functional differentiation among NCC varieties and GhF3’H acted in the accumulation of anthocyanin in fiber.Compared with GhF3’H,GhF3’5’H was expressed more highly in brown fiber with a longer duration of expression and caused lighter color of fibers in GhF3’5’H silenced lines.These three genes regulating fiber color depth and type could be used to improve these traits by genetic manipulation.

Desmosflavanone Ⅱ: A New Flavanone from Desmos cochinchinensis Lour

A new flavanone was isolated from the roots of Desmos cochinchinensis Lour Its chemical structure was elucidated by spectral analysis as 7 hydroxy 5 methoxy 8 formyl 6 methylflavanone, named desmosflavanone Ⅱ

First total synthesis of (±)-abyssinoflavanone V

The total synthesis of （±）-abyssinoflavanone V was first achieved through C-prenylation, selective protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap 4-hydroxybenzaldehyde and 2,4,6- trihydroxyacetophenone, with total yield 24%. All structures of new compounds were confirmed by IR, 1^H NMR and MS.

A New Flavanone and a New Flavanone Glycoside from Scutellaria baicalensis

A new flavanone （2S）-5, 7, 2＇, 5＇-tetrahydroxy-flavanone 1 together with a new flavanone glycoside （2S）-5, 7, 2＇, 5＇-tetrahydroxy-flavanone 7-O-13-D-glucopyranoside 2, were isolated from the dry roots of Scutellaria baicalensis. Their structures were elucidated on the basis of spectroscopic data.

Protective Actions of Blumea Flavanones on Primary Cultured Hepatocytes and Liver Subcellular Organelle against Lipid Peroxidation

To search for the protective actions of blumea flavanones (BFs) on hepatocytes and hepatic subcellular organelle against lipid peroxidation, monkey′s hepatocytes were isolated and cultured with or without blumea flavanones, then damaged by FeSO 4 cysteine or CCl 4. The lipid peroxidation (malondialdehyde production) and alteration in hepatocyte membrane (leakage of GPT) were estimated. Hepatic subcellular organelles were also isolated and incubated with or without blumea flavanones, then injured by FeSO 4 ascorbate. The generation of malondialdehyde(MDA) was measured. It was found that BFs 10 and 100 μmol·L 1 inhibited the MDA generation and GPT (glutamic pyruvic transaminase) leakage out of hepatocytes that were induced by CCl 4 or FeSO 4 cysteine. BFs could prevent lipid peroxidation initiated by FeSO 4 ascorbate in subcellular organelle suspension. Among BFs, BF 2 possessed the strongest activity. Conclusion: Blumea flavanones possess antioxidation activities that protect monkey′s hepatocytes and hepatic subcellular organelle against injuries induced by FeSO4 or CCl 4.

Two New Antibacterial Flavanones from Sophora flavescens

Two new lavandulylated flavanones,（2R, 3R）-8-1avandulyl-2＇-methoxy-5, 7, 4＇-trihydroxyflavanonol （1） and 8-1avandulyl-5,7, 4＇-trihydroxyflavonol （2）,were isolated from the dry roots of S opharaflavescens.Their structures were eiucidated on the basis of spectroscopic data. Compounds 1 and 2 exhibited significant antibacterial activities.

Solvent-free Synthesis of Flavanone over New Hybrid Mesoporous Base Catalysts

Benzyl and anthracenemethyl groups were respectively bonded to the N atoms of 3-aminopropyl functionalized mesoporous SBA-15（APS-SBA-15） to obtain two new base catalysts over which the condensation reaction of benzaldehyde and 2＇-hydroxyacetophenone was studied.Good catalytic activities and high selectivities for flavanones were obtained in solvent-free reactions,which is attributed to the effect of benzyl and anthracenemetyl groups on the base sites of catalysts and the steric hindrance of futher reaction of flavanone with benzaldehyde.

Influence of Mobile Phase Composition on the Enantioseparation of Methoxyl Flavanones with Self-prepared CDMPC Column and Chiral Recognition Mechanism

The influence of different alcohol modifiers in mobile phase on the chiral separation of 4-methoxyl flavanone, 5-methoxyl flavanone and 6-methoxyl flavanone on cellulose tris (3, 5-dimethylphenylcarbamate) (CDMPC) column was studied and the chiral recognition mechanism was discussed. Using hexane-tert-butanol (1.31 mol L-1) as the mobile phase, those three methoxyl flavanones were excellently separated on CDMPC chiral column.

Synthesis of New Flavanone Derivatives of Farrerol and Preliminary SAR Studies on Anti-VSMCs Vegetation Activity

A series of new flavanone derivatives of farrerol was designed and synthesized as a potent inhibitor of vascular smooth muscle cells（VSMCs） vegetation according to a convenient method. The structures of all the synthesized compounds were confirmed by 1H NMR, 13C NMR and EIHR-MS. The biological activities of these compounds against VSMCs in vitro were evaluated. The assay results indicate that two compounds, 5,7-dihydroxy-6,8-dimethyl- 2-（2-nitrophenyl）chroman-4-one（7f） and 2,3-dibromo-4,5-dihydroxydiphenylmethanone（7j） exhibited high activity against VSMCs in vitro with IC50 values of 9.9 and 6.7 μmol/L, respectively, and the preliminary structure-activity relationship（SAR） was described.

Two new flavanone glycosides from Macrothelypteris torresiana (Gaud.) Ching

Two new flavanone glycosides 1 and 2 were isolated from the aerial parts of Macrothelypteris torresiana （Gaud.） Ching. The structures of two products were identified as （2S）-5,7,2＇,5＇-tetrahydroxyflavanone-2＇-O-β-D-6＂-O-acetylglucopyranoside and （2S）- 5,7,2＇,5＇-tetrahydroxyflavanone-2＇-O-β-D-glucopyranoside on the basis of their chemical and spectral analysis, respectively.

Therapeutic Applications of Naringenin, a Flavanone Enriched in Citrus Fruits, for Disorders beyond Diabetes

In recent years,there has been an increase in epidemiological studies to highlight the health benefits of plant secondary metabolites.Flavonoids(polyphenolic plant secondary metabolites)are recently emerging as an important source for the discovery of new drugs increasing their pharmaceuticals,nutraceutical and medicinal applications.Naringenin is a flavanone,enriched in citrus fruits,tomatoes,bergamot,etc.which has been evaluated extensively for managing diabetes.However,in addition to this,naringenin had been ascribed to various important biological activities like antioxidant,antiviral,anticancer,anti-inflammatory,antiestrogenic,etc.This article aims at highlighting the therapeutic value of naringenin in managing disorders other than diabetes and its role in regulating gene expression by altering chromatin structure as histone deacetylase inhibitor.The understanding of these phenomena will increase the overall knowledge of the various health-promoting effects of citrus fruits.

A New Flavanone from the Bark of Morus macoura Miq.

A new flavanone named macrouroine C (1) was isolated from the bark of Morus macroura Miq.. The structure of 1 was elucidated mainly on the basis of spectroscopic evidence.

Crystal Structure of 2-[(N-methyl-N-phenyl ) aminomethyl] flavanone

The title compound 1 (C23H21NO2) was obtained by photoinduced reaction of flavone and N, N- dimethylaniline. The crystal structure of 1 has been determined by X-ray analysis. The crystal belongs to orthorhombic system, space group isPbca with a= 11. 799(2), b=11. 979(1), c=25. 972(3), V=3670. 9(5) , Z=8, Mr= 343. 4, Dc = 1.26 g/cm3, μ= 5. 98 cm-1, F(000) = 876 and the final R=0.073 and Rw =0.070 for 2235 observed diffractions. Structure analysis reveals thatthe pyran ring is distorted into a C(1)-sofa con formation.

New flavanone-monoterpene hybrids as α-glucosidase inhibitors from the root bark of Morus alba

Objective The Morus alba root bark is a well-known Chinese herbal medicine called Sang-Bai-Pi and has often been used to relieve the hyperglycemic symptom of diabetes patients.The current work aims to further explore its bioactive constituents with α-glucosidase inhibitory activity for the potential treatment of diabetes.Methods A combination of different separating techniques including routine column chromatograph and HPLC especially on chiral columns were applied for the isolation of target molecules,while comprehensive spectroscopic experiments comprising MS,NMR,ECD,etc.were carried out to complete the structural assignment.The anti-hyperglycemic property of the isolates was evaluated by an in vitro α-glucosidase inhibitory bioassay.Results Two pairs of new flavanone-monoterpene hybrid enantiomers were isolated and identified,and an interesting phenomenon of mutual transformation between these cometabolites were detected,which resulted in their regio-isomerization and enantiomerization.The bioassay results revealed remarkable α-glucosidase inhibitory activity for these fascinating molecules.Conclusions The Morus alba root bark is a rich source of bioactive flavonoid derivatives and deserves further investigations to develop new potential chemotherapies for diabetes control and treatment.

An overview of flavonoids from Sophora flavescens(kushen)with some emphasis on the anticancer properties of kurarinone and sophoraflavanone G

In this overview,the current knowledge of the constituents of flavonoids isolated from the roots of Sophora flavescens(kushen)is updated.Flavonoids consist of several classes,such as flavanones,flavonols,chalcones,isoflavones,biflavonoids,flavanols,and flavones.The most common compounds are kurarinone(KRN),sophoraflavanone G(SFG),2′-methoxykurarinone,kuraridine,isoxanthohumol,and formononetin.KRN and SFG are two major flavanones with more vital anticancer properties than other flavonoids.From the literature,the cytotoxic values of KRN and SFG are variable and depend on the type of cancer cells tested.The anticancer activities of these two flavonoids involve different molecular mechanisms.Clinical trials are needed before anticancer drugs from KRN and SFG can be developed.

Synthesis of Novel Flavanone Derivatives and Their Anti Staphylococcus aureus Evaluation

The authors synthesized two novel flavanones bearing iso-pentenyl side chain and evaluated their anti Staphylococcus aureus（S.aureus） activity.The target compounds 7a[2-5＇-（l＂,2＂-dimethylallyl）-2＇-methoxy-4＇,5,7-tetrahydroxyflavanone] and 7b[2-5＇-（l＂,2＂-dimethylallyl）-3＇-methoxy-4＇,5,7-tetrahydroxyflavanone] were synthesized respectively through total four steps starting from 2,4,6-trihydroxy acetophenone（3） and the corresponding iso-pentenyl substituted benzaldehyde（1）,in which the 1,2-dimethyl-2-propenyl group had been introduced previously via abnormal Claisen rearrangement.The bioactivities of the two flavanones against S.aureus strains ATCC 25923,29213,and MRSA 252 were evaluated,showing the same minimum inhibitory concentration（MIC） value of 16 μg/mL.

Chemical modification of acetaminophen：PASS assisted in vivo antiinflammatory activity of chalcones,flavanones and Schiff bases

In the present study,synthetic chalcones,flavanones and Schiff bases were prepared starting from paraceamol,and evaluated their anticipated anti-inflammatory activity.Chalcones were synthesized by reacting 3-acetyl-4-hydroxy acetanilide and aromatic aldehydes in alcoholic potassium hydroxide(KOH) solution under Claisen-Schmidt condensation conditions.The chalcones were cyclized in the presence of piperidine in isoamyl alcohol to obtain flavonone derivatives.Schiff bases were synthesized by condensing 3-acetyl-4-hydroxy anilines with aromatic aldehydes in the presence of HCl.These Schiff bases were further reacted with other aromatic aldehydes in alcoholic KOH solution.PASS cheminformatics software was used to predict the anti-inflammatory activity of synthesized compounds.PASS software predicted that chalcone-based Schiff bases 6a–d contained structural features that can exhibit anti-inflammatory activity.All the prepared derivatives of acetaminophen exhibited moderate to excellent in vivo anti-inflammatory activity in carrageenan-induced edema in rat paw.All the Schiff bases coupled chalcones showed good anti-inflammatory activity compared with the reference drug,diclofenac.Further evaluation of their therapeutic potential and safety profile is required in the future study.

New flavonoids from bioactive extract of Algerian medicinal plant Launeae arborescens

Objective:To investigate the butanol fraction of the water/acetone extract and isolate of the new flavonoids from Launeae arboescens.Methods:The compounds were isolated by liquid chromatographic methods and their structures were identified by using spectroscopic analysis.Results:The isolated compounds were identified as:7-0-[α-rhamnopyranosyl 4',5,6-Trihydroxy flavone 1,4',5'-Di-Methoxy 7-(5"-Me Hexan)1-oyl flavanone 2,3"-isopropyl pyrano[1":7,4":6]3',4',5',5-Tetrahydroxy flavanone 3,5,4',5'-Tri-Hydroxy 7-(3"-Me butan)-yl flavanone 4.5,7-Dihydroxy-2',4',5'-trimethoxy-isoflavanone 5,5,6,7,4'-tetrahydroxy flavonol 6,7-O-[α-rhamnopyranosyl-(1->6)-β-glucopyranosyl]-4',5,7-tri-hydroxy-flavanone 7,7-O-[α-rhamnopyranosyl-(1->6)-β-glucopyranosyl]3',5-Dihydroxy 4'-Methoxy flavanone 8.Conclusions:The presence of different types of bioactive flavonoids in Launeae arhoescens extract can explain the large ethnopharmacological uses and the potential activity of this medicinal plant.

First total synthesis of (±)-puyanin and (±)-4'-O-methylbonannione

A facile approach for the first total synthesis of two naturally occurring geranylated flavonoids,（±）-puyanin 1 and（±）-4＇-O- methylbonannione 2 has been obtained with total yield 27%and 21%,respectively.The key steps were regioselective cyclization of geranylated trihydroxychalcone and regioselective geranylation of 2,4,6-trihydroxyacetophenone.