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.

(±)-AbyssinoflavanoneⅤ的首次全合成

以廉价的对羟基苯甲醛和2,4,6-三羟基苯乙酮为起始原料,经过C-异戊烯基化,选择性保护酚羟基,羟醛缩合,催化环化和去保护基等步骤,首次以24%的总收率完成了天然产物(±)-AbyssinoflavanoneⅤ的全合成.所有新化合物的结构都经过1HNMR,IR,MS确认.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

Synthesis of O-Glycosides of Heteroatom Aroyl-Substituted Heterocyclic Ketene Aminals

Heteroatom aroyl-substituted heterocyclic ketene aminals 1 reacted with 2,3,4,6-tetra-O-acetyl-α-glucopyranosyl bromide 2 under the catalysis of Hg(CN)2 or CaH2 to give E- or Z-O-glycosides of heterocyclic ketene aminals 3 or 4 in moderate yields.

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.

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.

日本落叶松LkF3H2基因克隆及调控类黄酮代谢功能研究

【目的】日本落叶松黄烷酮3-羟化酶(flavanone 3-hydroxylase 2,LkF3H2)基因在类黄酮生物合成过程中发挥着重要的调控功能。探究LkF3H2基因在日本落叶松中发挥的具体功能和植物类黄酮生物代谢过程。【方法】根据实验室前期转录组数据克隆日本落叶松LkF3H2基因并进行生物信息学分析及组织表达分析。随后将该基因转化烟草进行转基因烟草组织表达分析及类黄酮含量测定,以探究基因表达量与类黄酮含量之间的关系。【结果】LkF3H2基因cDNA序列长度为1074 bp,其蛋白编码358个氨基酸,分子式C_(1785)H_(2807)N_(481)O_(541)S_(18),分子量为40.24 kD,该蛋白是不稳定的亲水性蛋白且不含信号肽;同时系统进化分析得出日本落叶松LkF3H2与火炬松、辐射松、白云杉和欧洲云杉F3H亲缘关系较近并且该蛋白含有保守结构域2OG-Fe(Ⅱ)oxygenase superfamily,属于2-酮戊二酸依赖性双加氧家族。另外组织表达分析显示LkF3H2基因在一月龄日本落叶松幼苗叶中表达量最高,在一年生日本落叶松幼苗茎中表达量最高,并且在转基因烟草叶中也显示了最高的表达量。值得一提的是,转基因烟草叶中的类黄酮含量也是最高的,其次为茎和根,转基因烟草中类黄酮含量与LkF3H2基因表达量呈正相关关系。【结论】日本落叶松LkF3H2基因属于2-酮戊二酸依赖性双加氧家族并且在类黄酮生物合成过程中发挥着重要功能。

比利时杜鹃花类黄酮3'-羟化酶(F3'H)基因克隆及功能分析

【目的】类黄酮3’-羟化酶(flavanone 3’-hydroxylase,F3’H)是植物花青素合成过程中的关键酶,探究比利时杜鹃花(Rhododendron hybridum Hort)F3’H基因的功能及表达特性。【方法】以比利时杜鹃花不同发育时期的花瓣及盛花期的根、茎、叶为实验材料,从比利时杜鹃花转录本数据库中筛选类黄酮生物合成通路关键酶类黄酮3’-羟化酶基因序列信息并进行生物信息学分析,利用反转录(RT-PCR)技术克隆RhF3’H基因;利用紫外分光光度计测定了比利时杜鹃花花瓣不同时期的花青素含量,利用RT-qPCR技术对不同发育时期花瓣和成熟期的不同组织进行RhF3’H基因表达量分析;采用Gateway技术构建过表达载体35S:RhF3’H-GFP重组载体进行亚细胞定位验证;构建p1302-RhF3’H过表达载体对比利时杜鹃花花瓣进行侵染。【结果】成功获得比利时杜鹃花RhF3’H基因长度为1557 bp,编码518个氨基酸,具有保守的F3’H结构域,属于P450超家族;系统进化树分析显示,比利时杜鹃花RhF3’H与龙眼和荔枝F3’H蛋白亲缘关系最近;RT-qPCR结果显示,RhF3’H在比利时杜鹃花不同花瓣时期和根、茎、叶组织中均有表达,在不同花瓣发育时期中,盛开期和衰败期中RhF3’H基因的表达量较高,与花青素含量结果相一致;亚细胞定位分析显示,RhF3’H主要存在于细胞膜上;成功构建P1302-RhF3’H瞬时过表达载体,相较于CK和p1302,p1302-RhF3’H在杜鹃花花瓣中显著高表达,其花青素含量也显著增加。【结论】RhF3’H基因在花瓣细胞膜中表达,表达模式与花青素积累趋势一致;过表达RhF3’H基因促进了花青素的合成。

添加蒲公英对苜蓿青贮品质及抗氧化活性的影响

将药用蒲公英(Taraxacum officinale)分别以0(对照组,CK)、2%、4%、6%和8%添加至苜蓿(Medicago sativa)中进行青贮,每组4个重复,发酵60 d后测定青贮营养成分、发酵品质及抗氧化活性。结果表明,与CK相比,在营养品质上,4%组的干物质(DM)和粗脂肪(EE)含量显著增加(P<0.05),分别为37.85%和2.08%,6%组的EE和可溶性碳水化合物(WSC)含量显著增加,分别为2.27%和6.52%,6%和8%组的中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量均显著降低,分别为37.82%、32.17%和34.85%和30.12%。发酵品质上,所有蒲公英添加组青贮的pH和丙酸(PA)含量均显著降低;所有蒲公英添加组乙酸(AA)含量均显著增加,均在1.00%以上,4%组乳酸(LA)含量和乳酸菌(LAB)数量均显著增加,分别为4.85%和7.19 lg(cfu·g^(−1)),且氨态氮(NH_(3)-N)含量显著降低,为2.46%。抗氧化活性上,8%组类黄酮含量显著增加,为1.37%,4%、6%和8%组的总酚和总多糖含量及谷胱甘肽过氧化物酶(GSH-Px)活性均显著提高,6%组青贮的超氧化物歧化酶(SOD)活性显著提高,为241.37 U·mg^(−1),2%和6%组青贮的1,1-二苯基-2-三硝基苯肼(DPPH)清除率均显著提高,且均在90.00%以上;2%、4%和8%组青贮的总抗氧化能力(T-AOC)均显著提高,分别为0.51、0.60和0.43 mmol·L^(−1)。主成分分析和综合得分排名表现为6%组>4%组>2%组>8%组>CK。综上所述,蒲公英添加量为6.0%时对苜蓿青贮的营养品质、发酵品质和抗氧化活性效果最好。