- Flavone synthase II (CYP93B16) from soybean (Glycine max L.)
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Flavonoids are a very diverse group of plant secondary metabolites with a wide array of activities in plants, as well as in nutrition and health. All flavonoids are derived from a limited number of flavanone intermediates, which serve as substrates for a variety of enzyme activities, enabling the generation of diversity in flavonoid structures. Flavonoids can be characteristic metabolites, like isoflavonoids for legumes. Others, like flavones, occur in nearly all plants. Interestingly, there exist two fundamentally different enzymatic systems able to directly generate flavones from flavanones, flavone synthase (FNS) I and II. We describe an inducible flavone synthase activity from soybean (Glycine max) cell cultures, generating 7,4′-dihydroxyflavone (DHF), which we classified as FNS II. The corresponding full-length cDNA (CYP93B16) was isolated using known FNS II sequences from other plants. Functional expression in yeast allowed the detailed biochemical characterization of the catalytic activity of FNS II. A direct conversion of flavanones such as liquiritigenin, naringenin, and eriodictyol into the corresponding flavones DHF, apigenin and luteolin, respectively, was demonstrated. The enzymatic reaction of FNS II was stereoselective, favouring the (S)- over the (R)-enantiomer. Phylogenetic analyses of the subfamily of plant CYP93B enzymes indicate the evolution of a gene encoding a flavone synthase which originally catalyzed the direct conversion of flavanones into flavones, via early gene duplication into a less efficient enzyme with an altered catalytic mechanism. Ultimately, this allowed the evolution of the legume-specific isoflavonoid synthase activity.
- Fliegmann, Judith,Furtw?ngler, Katarina,Malterer, Georg,Cantarello, Corrado,Schüler, G?de,Ebel, Jürgen,Mith?fer, Axel
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- Synthesis and studies of flavone and bis-flavone derivatives
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Flavonoids are widely occurring polyphenols of plant origin and well explored in the field of pharmacological activities. Recent studies showed this scaffold to be more dynamic as fluorescent probe. Very rare reports are there in literature on flavones as liquid crystals, for the first time we have synthesized and characterized flavone and bis-flavone derivatives for mesomorphic properties. Compounds 9a–d and 13a–d were studied for liquid crystalline properties by Differential scanning calorimetry (DSC) and Polarizing optical microscopy (POM) studies. The compounds 8, 9a–d, 12, and 13a–d were also studied for antioxidant property by DPPH assay.
- Durgapal, Sunil Dutt,Soman, Shubhangi S.,Umar, Shweta,Balakrishnan, Suresh
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- Isoliquiritigenin Derivatives Inhibit RANKL-Induced Osteoclastogenesis by Regulating p38 and NF-κB Activation in RAW 264.7 Cells
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Bone diseases may not be imminently life-threatening or a leading cause of death such as heart diseases or cancers. However, as aging population grows in almost every part of the world, they surely impose significant socioeconomic burden on the society, not to mention the patients and their families. Osteoporosis is the most common type of bone disease, which frequently develops in seniors, especially in postmenopausal women. Although currently several anti-osteoclastic drugs designed to suppress excessive osteoclast activation, a major cause of osteoporosis, are commercially available, accompanying adverse effects ranging from mild to severe have been reported as well. Natural products have become increasingly popular because of their effectiveness with fewer side effects. Isoliquiritigenin (ILG), a natural flavonoid from licorice, has been reported to suppress osteoclast differentiation and activation. In the present study, newly synthesized ILG derivatives were screened for their anti-osteoporotic activity as more potent substitute candidates to ILG. Out of the 12 ILG derivatives tested, two compounds demonstrated significantly improved bone loss in vitro by inhibiting both osteoclastogenesis and osteoclast activity. The results of the present study indicate that these compounds may serve as a potential drug for osteoporosis and warrant further studies to evaluate their in vivo efficacy.
- Choi, Jung-Won,Hwang, Ki-Chul,Jeong, Seongtae,Kim, Kundo,Kim, Sang Woo,Lee, Jiyun,Lee, Seahyoung,Lee, Yunmi,Lim, Soyeon,Oh, Sena
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supporting information
(2020/09/17)
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- A method of synthesizing the glycyrrhizin (by machine translation)
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The invention relates to a synthetic chemical method of glycyrrhizin. In order to 2, 4 - dihydroxy acetophenone and 4 - hydroxy benzoic acid ethyl ester as the raw material, the protective group for a hydroxyl, keto ester condensation, cyclization and hyd
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- Identification of metabolites of liquiritin in rats by UHPLC-Q-TOF-MS/MS: Metabolic profiling and pathway comparison: In vitro and in vivo
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Liquiritin (LQ), the main bioactive constituent of licorice, is a common flavoring and sweetening agent in food products and has a wide range of pharmacological properties, including antidepressant-like, neuroprotective, anti-cancer and anti-inflammatory properties. This study investigated the metabolic pathways of LQ in vitro (rat liver microsomes) and in vivo (rat model) using ultra high-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). Moreover, supplementary tools such as key product ions (KPIs) were employed to search for and identify compounds. As a result, 56 in vivo metabolites and 15 in vitro metabolites were structurally characterized. Oxidation, reduction, hydrolysis, methylation, acetylation, and sulfate and glucuronide conjugation were determined to be the major metabolic pathways of LQ, and there were differences in LQ metabolism in vitro and in vivo. In addition, the in vitro and in vivo metabolic pathways were compared in this study.
- Zhang, Xia,Liang, Caijuan,Yin, Jintuo,Sun, Yupeng,Zhang, Lantong
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p. 11813 - 11827
(2018/04/05)
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- Synthesis and antiproliferative activity of some dihydro-1 H-furo[2,3-c]pyrazole-Flavone hybrids
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A new series of dihydro-1 H-furo[2,3-c]pyrazole-flavone hybrids were synthesized from one-pot four-component reaction of β-keto ester (1), hydrazine (2),7-hydroxy 8-formyl flavones (3), pyridiniumylide (4) in presence of NEt3 as catalyst under ethanol reflux conditions and their antiproliferative properties were evaluated against human cancer cell lines, namely, laryngeal carcinoma (Hep2), lung adenocarcinoma (A549) and cervical cancer (HeLa). The best among them, furo[2,3-c]pyrazole-flavone with C4′-methoxy substitution was selected for further structure activity relationship (SAR) studies. Among the derivatives, (4S,5S)-ethyl 4-(7-hydroxy-5-methoxy-4-oxo-2-(2,4,6-trimethoxyphenyl)-4H-chromen-8-yl)-3-methyl-4,5-dihydro-1 H-furo[2,3-c]pyrazole-5-carboxylate (8r) showed most potent cytotoxic activity against all three cancer cell lines. Toxicity studies revealed that the dihydro-1H-furo[2,3-c]pyrazole-flavones are specifically target the cancer cell lines.
- Tangeti, Venkata Swamy,Vasundhara,Satyanarayana,Pavan Kumar, Kaja Srinivas
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p. 1525 - 1532
(2017/05/29)
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- Synthesis of a series of novel dihydroartemisinin monomers and dimers containing chalcone as a linker and their anticancer activity
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A new series of monomer and dimer derivatives of dihydroartemisinin (DHA) containing substituted chalcones as a linker were synthesized and investigated for their cytotoxicity in human cancer cell lines HL-60 (leukemia), Mia PaCa-2 (pancreatic cancer), PC
- Gaur, Rashmi,Pathania, Anup Singh,Malik, Fayaz Ahmad,Bhakuni, Rajendra Singh,Verma, Ram Kishor
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p. 232 - 246
(2016/07/07)
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- Inhibitory effect of flavonoids on human glutaminyl cyclase
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Glutaminyl cyclase (QC) plays an important role in the pathogenesis of Alzheimer's disease (AD) and can be a potential target for the development of novel anti-AD agents. However, the study of QC inhibitors are still less. Here, phenol-4′ (R1-), C5-OH (R2-) and C7-OH (R3-) modified apigenin derivatives were synthesized as a new class of human QC (hQC) inhibitors. The efficacy investigation of these compounds was performed by spectrophotometric assessment and the structure-activity relationship (SAR) was evaluated. Molecular docking was also carried out to analyze the binding mode of the synthesized flavonoid to the active site of hQC.
- Li, Manman,Dong, Yao,Yu, Xi,Zou, Yongdong,Zheng, Yizhi,Bu, Xianzhang,Quan, Junmin,He, Zhendan,Wu, Haiqiang
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p. 2280 - 2286
(2016/04/26)
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- Design, synthesis and evaluation of novel 7-aminoalkyl-substituted flavonoid derivatives with improved cholinesterase inhibitory activities
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A novel series of 7-aminoalkyl-substituted flavonoid derivatives 5a-5r were designed, synthesized and evaluated as potential cholinesterase inhibitors. The results showed that most of the synthesized compounds exhibited potent acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities at the micromolar range. Compound 2-(naphthalen-1-yl)-7-(8-(pyrrolidin-1-yl)octyloxy)-4H-chromen-4-one (5q) showed the best inhibitory activity (IC50, 0.64 μM for AChE and 0.42 μM for BChE) which were better than our previously reported compounds and the commercially available cholinergic agent Rivastigmine. The results from a Lineweaver-Burk plot indicated a mixed-type inhibition for compound 5q with AChE and BChE. Furthermore, molecular modeling study showed that 5q targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. Besides, these compounds (5a-5r) did not affect PC12 and HepG2 cell viability at the concentration of 10 μM. Consequently, these flavonoid derivatives should be further investigated as multipotent agents for the treatment of Alzheimer's disease.
- Luo, Wen,Chen, Ying,Wang, Ting,Hong, Chen,Chang, Li-Ping,Chang, Cong-Cong,Yang, Ya-Cheng,Xie, Song-Qiang,Wang, Chao-Jie
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p. 672 - 680
(2016/02/09)
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- Microbial metabolism. Part 6. Metabolites of 3- and 7-hydroxyflavones
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Fermentation of 3-hydroxyflavone (1) with Beauveria bassiana (ATCC 13144) yielded 3,4′-dihdroxyflavone (3), flavone 3-O-β-D-4-O- methylglucopyranoside (4) and two minor metabolites. 7-Hydroxyflavone (2) was transformed by Nocardia species (NRRL 5646) to 7-methoxyflavone (5) whilst Aspergillus alliaceus (ATCC 10060) converted it to 4′,7-dihydroxyflavone (6). Flavone 7-O-β-D-4-O-metylglucopyranoside (7) and 4′- hydroxyflavone 7-O-β-D-4-O-methylglucopyranoside (8) were the metabolic products of 7-hydroxyflavone (2) when fermented with Beauveria bassiana (ATCC 7159). One of the minor metabolites of 3-hydroxyflavone (1) was tentatively assigned a β′-chalcanol structure (9). Compounds 4, 7 and 8 are reported as new compounds. Structure elucidation of the metabolites was based on spectroscopic data.
- Herath, Wimal,Mikell, Julie Rakel,Hale, Amber Lynn,Ferreira, Daneel,Khan, Ikhlas Ahmad
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p. 320 - 324
(2007/10/03)
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- COMPOUNDS FOR IMMUNOPOTENTIATION
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Methods of stimulating an immune response and treating patients responsive thereto with 3,4-di(1H-indol-3-yl)-1H-pyrrole-2,5-diones, staurosporine analogs, derivatized pyridazines, chromen-4-ones, indolinones, quinazolines, nucleoside analogs, and other small molecules are disclosed.
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Page/Page column 118
(2010/02/15)
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- Cleavage of methyl ethers of flavones by chloroaluminate ionic liquid
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A new o-demethylation method of a series of mono-, di-, trimethoxy-flavones using a chloroaluminate ionic liquid - [BMIM] [Al2Cl7] in dichloromethane is described. The desired products were obtained in moderate to good yields.
- Liu, Tao,Hu, Yongzhou
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p. 3209 - 3218
(2007/10/03)
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- Peroxidase from cell cultures of cassia didymobotrya: A review and comparison with horseradish peroxidase
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The catalytic activity on flavonoids and dibenzylbutanolides and the specificity of the peroxidase isolated from 29d-old cell cultures of Cassia didymobotrya are reported. Studies on several substrates in comparison with horseradish peroxidase revealed pe
- Botta, Bruno,Ricciardi, Paola,Vitali, Alberto,Vinciguerra, Vittorio,Garcia, Carlos,Delle Monache, Giuliano
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p. 757 - 766
(2007/10/03)
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- 1-Benzopyran-4-one antioxidants as aldose reductase inhibitors
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Starting from the inhibitory activity of the flavonoid Quercetin, a series of 4H-1-benzopyran-4-one derivatives was synthesized and tested for inhibition of aldose reductase, an enzyme involved in the appearance of diabetic complications. Some of the compounds obtained display inhibitory activity similar to that of Sorbinil but are more selective than Quercetin and Sorbinil with respect to the closely related enzyme, aldehyde reductase, and also possess antioxidant activity. Remarkably, these compounds possess higher pK(a) values than carboxylic acids, a characteristic which could make the pharmacokinetics of these compounds very interesting. Molecular modeling investigations on the structures of inhibitors bound at the active site of aldose reductase were performed in order to suggest how these new inhibitors might bind to the enzyme and also to interpret structure-activity relationships.
- Costantino, Luca,Rastelli, Giulio,Gamberini, Maria Cristina,Vinson, Joe A.,Bose, Pratima,Iannone, Anna,Staffieri, Mariagrazia,Antolini, Luciano,Del Corso, Antonella,Mura, Umberto,Albasini, Albano
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p. 1881 - 1893
(2007/10/03)
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- Flavonoids, 45 . A General and Efficient Synthesis of Hydroxyflavones and -chromones
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An efficient and versatile method for the synthesis of flavones hydroxylated in either ring A or B and of chromones hydroxylated in is described.This approach is based on the acidic resin-promoted cyclodehydration and simultaneous deprotection of methoxymethoxylated 1-(2-hydroxyphenyl)propane-1,3-diones easily available by either the Baker-Venkataraman rearrangement or the Claisen condensation. - Key words: Amberlyst 15 / Baker-Venkataraman rearrangement / Claisen condensation / hydroxychromone / hydroxyflavone / methoxymethyl protection
- Patonay, Tamas,Molnar, Denes,Muranyi, Zoltan
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p. 233 - 242
(2007/10/02)
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- Synthesis of Flavones via Application of the Nitrile Oxide and the Stille Reactions
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Hydroxylated and methoxylated benzaldehyde oximes have been chlorinated, dehydrohalogenated and cycloadded to tributylstannylacetylene to give 3-aryl-5-tributylstannylisoxazoles in good to excellent yields.The palladium-catalyzed coupling reaction, the so-called Stille reaction, of hindered and electron-rich 2-iodophenols and a 2-iodo-1,4-benzoquinone with 3-aryl-5-tributylstannyl-isoxazoles gave 3-aryl-5-(2-hydroxyaryl)isoxazoles in moderate to excellent yields.The coupling reaction was studied under various conditions and with various Pd(II) and Pd(0) complexes.Reduction of the 3,5-diarylisoxazoles with H2/Raney-Ni, hydrolysis and acid-catalyzed cyclisation gave flavones.The synthesis of 2-iodo-3,5-dimethoxy-1,4-benzoquinone is described.
- Gothelf, Kurt V.,Torssell, Kurt B. G.
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- A Short and Facile Synthetic Route to Hydroxylated Flavones. New Syntheses of Apigenin, Tricin, and Luteolin
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Reaction of lithium polyanions generated from o-hydroxyacetophenones 3a-f with O-silyloxylated benzoates 2a-d gave 1-aryl-3-(2-hydroxyphenyl)-1,3-propanediones 4a-n, which on treatment with acetic acid containing 0.5percent H2SO4 at 95 - 100 deg C afforded hydroxylated flavones 5-18 in high yields (76 - 92percent).
- Nagarathnam, Dhanapalan,Cushman, Mark
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p. 4884 - 4887
(2007/10/02)
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- Flavonoids from the cultured cells of Glycyrrhiza echinata
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Constituents of the cultured cells of Glycyrrhiza echinata have been investigated. Echinatin (4,4′-dihydroxy-2-methoxychalcone), a biosynthetically unique retrochalcone, and licodione (1-(2,4-dihydroxyphenyl)-3-(4-hydroxyphenyl)-1,3-propanedione), a dibezoylmethane derivative, which is the possible precursor of echinatin, were obtained. The structures were determined by spectroscopic methods and syntheses. 1H NMR of licodione revealed new features in chemical shifts of protons of diketonic and keto-enolic forms. 7,4′-Dihydroxyflavone, two of its prenyl derivatives and formononetin were also isolated. A discussion on retrochalcone biosynthesis is presented.
- Ayabe, Shin-Ichi,Kobayashi, Miyuki,Hikichi, Manabu,Matsumoto, Kazuo,Furuya, Tsutomu
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p. 2179 - 2183
(2007/10/02)
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