- KNIPHOLONE: A UNIQUE ANTHRQUINONE DERIVATIVE FROM KNIPHOFIA FOLIOSA
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The roots of Kniphofia foliosa afforded, in addition to chrysophanol, a novel anthraquinone named knipholone, whose structure was determined by spectroscopic methods as well as by degradation to known compounds.Key Word Index - Kniphofia foliosa; Liliaceae; anthraquinone; chrysophanol; knipholone.
- Dagne, Ermias,Steglich, Wolfgang
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- Bulbine-knipholone, a new, axially chiral phenylanthraquinone from Bulbine abyssinica (Asphodelaceae): Isolation, structural elucidation, synthesis, and antiplasmodial activity
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A new natural phenylanthraquinone, bulbine-knipholone (6), has been isolated from the African plant species Bulbine abyssinica (Asphodelaceae). Its structure was determined by spectroscopic and degradative methods. With the aid of the "lactone concept", an atropo-enantioselective total synthesis has been elaborated, confirming the full absolute structure. Bulbine-knipholone exhibits antiplasmodial activity. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Bringmann, Gerhard,Menche, Dirk,Brun, Reto,Msuta, Thomas,Abegaz, Berhanu
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- Effects of substituent pattern on the intracellular target of antiproliferative benzo[b]thiophenyl chromone derivatives
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A new biological scaffold was produced by replacing the 6π-electron phenyl ring-B of a natural flavone skeleton with a 10π-electron benzothiophene (BT). Since aromatic rings are important for ligand protein interactions, this expansion of the π-electron system of ring-B might change the bioactivity profile. One of the resulting novel natural product-inspired compounds, 2-(benzo[b]thiophen-3-yl)-5-hydroxy-7-isopropoxy-6-methoxyflavone (6), effectively arrested the cell cycle at the G2/M phase and displayed significant antiproliferative effects with IC50 values of 0.05–0.08 μM against multiple human tumor cell lines, including a multidrug resistant line. A structure-activity relationship study revealed that a 10π-electron system with high aromaticity, juxtaposed 4-oxo and 5-hydroxy groups, and 7-alkoxy groups were important for potent antimitotic activity. Interestingly, two BT-flavonols (3-hydroxyflavone), 16 and 20, with 3-hydroxy and 5-alkoxy groups, induced distinct biological profiles affecting the cell cycle at the G1/S phase by inhibition of DNA replication through an interaction with topoisomerase I.
- Goto, Masuo,Hamel, Ernest,Hirazawa, Sachika,Miura, Yuta,Nakagawa-Goto, Kyoko,Nakayoshi, Tomoki,Oda, Akifumi,Saito, Yohei,Taniguchi, Yukako,Tsurimoto, Hiroyuki,Yamashita, Katsumi
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- AN ANTHRONE, AN ANTHRAQUINONE AND TWO OXANTHRONES FROM KNIPHOFIA FOLIOSA
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The compounds isoknipholone, isoknipholone anthrone, foliosone and isofoliosone were isolated from the stem of Kniphofia foliosa and their structures determined by spectral analyses.In addition, the known compounds, aloesaponol III, aloesaponol III-8-methyl ether and 4,6-dihydroxy-2-methoxyacetophenone were isolated and identified. - Key words: Kniphofia foliosa; Asphodelaceae; stem; anthrone; anthraquinone; oxanthrones; isoknipholone anthrone; isoknipholone; foliosone; isofoliosone.
- Yenesew, Abiy,Dagne, Ermias,Mueller, Michael,Steglich, Wolfgang
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- Annphenone, a phenolic acetophenone from Artemisia annua
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Fractionation of the n-butanol extract of Artemisia annua led to the isolation of a new phenolic acetophenone, the structure of which was elucidated as 2,4-dihydroxy-6-methoxy-acetophenone 40-O-β-D-glucopyranoside on the basis of spectroscopic data.
- Singh, Anil K.,Pathak, Vibha,Agrawal, Pawan K.
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- Neuroregenerative Potential of Prenyl- And Pyranochalcones: A Structure-Activity Study
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Loss of neuronal tissue is a hallmark of age-related neurodegenerative diseases. Since adult neurogenesis has been confirmed in the human brain, great interest has arisen in substances stimulating the endogenous neuronal regeneration mechanism based on ad
- Aigner, Ludwig,Bieler, Lara,Couillard-Despres, Sebastien,Priglinger, Eleni,Riepl, Herbert M.,Urmann, Corinna
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p. 2675 - 2682
(2021/10/12)
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- Design, synthesis and biological evaluation of dimethyl cardamonin (DMC) derivatives as P-glycoprotein-mediated multidrug resistance reversal agents
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Background: P-glycoprotein (P-gp) has been regarded as an important factor in the multidrug resistance (MDR) of tumor cells within the last decade, which can be solved by inhibiting P-gp to reverse MDR. Thus, it is an effective strategy to develop inhibitor of P-gp. Objective: In this study, the synthesis of a series of derivatives had been carried out by bioisosterism design on the basis of Dimethyl Cardamonin (DMC). Subsequently, we evaluated their reversal activities as potential P-glycoprotein (P-gp)-mediated Multidrug Resistance (MDR) agents. Methods: Dimethyl cardamonin derivatives were synthesized from acetophenones and the corresponding benzaldehydes in the presence of 40% KOH by Claisen-Schmidt reaction. Their cytotoxicity and reversal activities in vitro were assessed with MTT. Moreover, the compound B4 was evaluated by Doxorubicin (DOX) accumulation, Western blot and wound-healing assays deeply. Results and Discussion: The results showed that compounds B2, B4 and B6 had the potency of MDR reversers with little intrinsic cytotoxicity. Meanwhile, these compounds also demonstrated the capability to inhibit MCF-7 and MCF-7/DOX cells migration. Besides, the most compound B4 was selected for further study, which promoted the accumulation of DOX in MCF-7/DOX cells and inhibited the expressionof P-gp at protein levels. Conclusion: The above findings may provide new insights for the research and development of P-gp-mediated MDR reversal agents.
- Liu, Jianwen,Ma, Lei,Shi, Ximeng,Yin, Huanhuan,Zhao, Yuyu,Zhou, Licheng
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p. 1270 - 1282
(2020/10/06)
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- Biocatalytic Friedel–Crafts Acylation and Fries Reaction
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The Friedel–Crafts acylation is commonly used for the synthesis of aryl ketones, and a biocatalytic version, which may benefit from the chemo- and regioselectivity of enzymes, has not yet been introduced. Described here is a bacterial acyltransferase which can catalyze Friedel–Crafts C-acylation of phenolic substrates in buffer without the need of CoA-activated reagents. Conversions reach up to >99 %, and various C- or O-acyl donors, such as DAPG or isopropenyl acetate, are accepted by this enzyme. Furthermore the enzyme enables a Fries rearrangement-like reaction of resorcinol derivatives. These findings open an avenue for the development of alternative and selective C?C bond formation methods.
- Schmidt, Nina G.,Pavkov-Keller, Tea,Richter, Nina,Wiltschi, Birgit,Gruber, Karl,Kroutil, Wolfgang
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supporting information
p. 7615 - 7619
(2017/06/13)
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- Acyl Donors and Additives for the Biocatalytic Friedel–Crafts Acylation
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The Friedel–Crafts acylation is a broadly applied reaction that can be conducted using various types of catalyst. However, a biocatalytic alternative has only been reported recently. In this study, the scope of acetyl donors is described, showing that, in addition to vinyl acetate derivatives, phenyl esters are also suitable donors. Furthermore, it was found that various amines enhance the reaction, whereby the effect do not seem to be correlated to the pH but to the structure of the donor. For instance, 1,4-diazabicyclo[2.2.2]octane (DABCO) turned out to be a viable alternative to imidazole; however the former performed best at pH 9.85, whereas the latter performed best at pH 8.3.
- Schmidt, Nina G.,Kroutil, Wolfgang
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p. 5865 - 5871
(2017/10/07)
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- Mallotojaponins B and C: Total Synthesis, Antiparasitic Evaluation, and Preliminary SAR Studies
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(Chemical Equation Presented). The first total syntheses of mallotojaponin B and C as well as several analogues have been achieved. Biological evaluation of the synthesized compounds against Plasmodium falciparum and Trypanosoma brucei have also been carried out.
- Grayfer, Tatyana D.,Grellier, Philippe,Mouray, Elisabeth,Dodd, Robert H.,Dubois, Jo?lle,Cariou, Kevin
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supporting information
p. 708 - 711
(2016/03/01)
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- Practical metal-free synthesis of chalcone derivatives via a tandem cross-dehydrogenative-coupling/elimination reaction
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Metal-free synthesis of chalcone derivatives through a tandem cross-dehydrogenative-coupling/elimination reaction is described. A simple and inexpensive ammonium persulfate salt enables the reaction between ketones and benzylamines to proceed with high stereoselectivity and good functional group compatibility.
- Wei, Yu,Tang, Jinghua,Cong, Xuefeng,Zeng, Xiaoming
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supporting information
p. 3165 - 3169
(2013/11/06)
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- Prenylflavonoids and prenyl/alkyl-phloroacetophenones: Synthesis and antitumour biological evaluation
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Several prenylflavonoids have been synthesised and tested against human tumour cell lines. The prenyl unit has been geranyl or a labdane diterpene. These labdane-flavonoids have been synthesised for the first time. The antitumour activity increase with the prenylation at C-8 position. Twenty-three C and O-prenylated acylphloroglucinols have been synthesised as well. In this case the C-alkylation products have resulted, in general, more active.
- Basabe,De Román,Marcos,Diez,Blanco,Bodero,Mollinedo,Sierra,Urones
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experimental part
p. 4258 - 4269
(2010/10/01)
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- COMPOUNDS, THEIR SYNTHESES, AND THEIR USES
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Embodiments of the present invention provide compounds (such as Formula (I) compounds, Formula (II) compounds, and various embodiments thereof). Compositions comprising those compounds are also provided. Methods for their preparation are included. Also, uses of the compounds are included, such as administering and treating diseases (e.g., cancer and infections).
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Page/Page column 38; 50
(2010/04/03)
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- In vitro and in vivo anti-Leishmania activity of polysubstituted synthetic chalcones
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The in vitro screening of 43 polysubstituted chalcones against Leishmania amazonensis axenic amastigotes, led to the evaluation of 9 of them in a macrophage-infected model with the two other most infectious Leishmania species prevalent in Peru (L. braziliensis and L. peruviana). The five most active and selective chalcones were studied in vivo, resulting on the identification of two chalcones with high reduction parasite burden percentages.
- Aponte, Jose C.,Castillo, Denis,Estevez, Yannick,Gonzalez, German,Arevalo, Jorge,Hammond, Gerald B.,Sauvain, Michel
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scheme or table
p. 100 - 103
(2010/04/06)
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- Synthesis, cytotoxicity, and anti-Trypanosoma cruzi activity of new chalcones
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Synthesis of a cytotoxic dihydrochalcone, first isolated from a traditional Amazonian medicinal plant Iryanthera juruensis Warb (Myristicaceae), followed by a comprehensive SAR analysis of saturated and unsaturated chalcone synthetic intermediates, led to the identification of analogues with selective and significant in vitro anti-Trypanosoma cruzi activity. Further SAR studies were undertaken with the synthesis of 21 new chalcones containing two allyloxy moieties that resulted in the discovery of 2′,4′-diallyloxy- 6′-methoxy chalcones with improved selectivity against this parasite at concentrations below 25 μM, four of which exhibited a selectivity index greater than 12.
- Aponte, José C.,Verástegui, Manuela,Málaga, Edith,Zimic, Mirko,Quiliano, Miguel,Vaisberg, Abraham J.,Gilman, Robert H.,Hammond, Gerald B.
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experimental part
p. 6230 - 6234
(2009/09/25)
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- The flavone hispidulin, a benzodiazepine receptor ligand with positive allosteric properties, traverses the blood-brain barrier and exhibits anticonvulsive effects
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1 The functional characterization of hispidulin (4′,5,7-trihydroxy-6- methoxyflavone), a potent benzodiazepine (BZD) receptor ligand, was initiated to determine its potential as a modulator of central nervous system activity. 2 After chemical synthesis, hispidulin was investigated at recombinant GABA A/BZD receptors expressed by Xenopus laevis oocytes. Concentrations of 50 nM and higher stimulated the GABA-induced chloride currents at tested receptor subtypes (α 1-3,5,6β2γ2S) indicating positive allosteric properties. Maximal stimulation at α1β 2γ2S was observed with 10 μM hispidulin. In contrast to diazepam, hispidulin modulated the α6β 2γ2S-GABAA receptor subtype. 3 When fed to seizure-prone Mongolian gerbils (Meriones unguiculatus) in a model of epilepsy, hispidulin (10 mg kg-1 body weight (BW) per day) and diazepam (2 mg kg-1 BW per day) markedly reduced the number of animals suffering from seizures after 7 days of treatment (30 and 25% of animals in the respective treatment groups, vs 80% in the vehicle group). 4 Permeability across the blood-brain barrier for the chemically synthesized, 14C-labelled hispidulin was confirmed by a rat in situ perfusion model. With an uptake rate (Kin) of 1.14 ml min-1 g -1, measurements approached the values obtained with highly penetrating compounds such as diazepam. 5 Experiments with Caco-2 cells predict that orally administered hispidulin enters circulation in its intact form. At a concentration of 30 μM, the flavone crossed the monolayer without degradation as verified by the absence of glucuronidated metabolites.
- Kavvadias, Dominique,Sand, Philipp,Youdim, Kuresh A.,Qaiser, M. Zeeshan,Rice-Evans, Catherine,Baur, Roland,Sigel, Erwin,Rausch, Wolf-Dieter,Riederer, Peter,Schreier, Peter
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p. 811 - 820
(2007/10/03)
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- Synthesis of maritimin, a chromone from Pancratium maritimum
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The synthesis of maritimin (1), a chromone from Pancratium maritimum L., is described.
- Asolkar, Ratnakar N.,Kamat, Vijayendra P.,Kirtany, Janardan K.
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p. 549 - 550
(2007/10/03)
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- Synthesis of Pyranoisoflavones from Pyronochalcones: Synthesis of Elongatin and Its Angular Isomer
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Elongatin (4',5-dihydroxy-2',5'-dimethoxy-2'',2''-dimethylpyranoisoflavone) was synthesized by an oxidative rearrangement of the corresponding pyronochalcone with thallium(III) nitrate and a regioselective reduction of 7-(4-benzoyloxy-2,5-dimethoxyphenyl)-2,3-dihydro-2,2-dimethyl-5-tosyloxy-4H,6H-benzodipyran-4,6-dione with sodium borohydride-palladium chloride, followed by dehydration of the resultant alcohol and hydrolysis.Its angular isomer (4',5-dihydroxy-2',5'-dimethoxy-2'',2''-dimethylpyranoisoflavone) was also synthesized from the corresponding pyronochalcone in a similar manner.
- Tsukayama, Masao,Kawamura, Yasuhiko,Tamaki, Hiroto,Kubo, Tomoya,Horie, Tokunaru
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p. 826 - 832
(2007/10/02)
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- Synthesis of a New Flavone
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The structure of the naturally occuring flavone 5-O-methylacacetin (I) has been confirmed by its synthesis. 5,7-Di-O-methylacacetin has been synthesised.
- Srivastava, Savitri D.,Srivastava, Santosh K.
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- SYNTHESIS OF UVARETIN, AN ANTITUMOUR AND ANTIMICROBIAL FLAVONOID
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The flavonoid uvaretin (1-(2,4-dihydroxy-6-methoxy-3-((2-hydroxyphenyl)-methyl)-phenyl)-3-phenyl-1-propanone), known to be active against some tumours and several bacteria, has been synthesized in six steps from 2',4',6'-trimethoxyacetophenone, 2-hydroxybenzaldehyde and benzaldehyde.
- Malterud, Karl Egil,Undheim, Jorunn,Erdal, John Erik
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p. 4807 - 4810
(2007/10/02)
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- Aromatic Benzhydrylation: Part III - Synthesis of Chromones of Triphenylmethane Type
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2-O-Methylphloroacetophenone (1) when treated with diphenylcarbinol in the presence of boron trifluoride etherate and dioxan gives a mixture of 3-C-benzhydryl-(4a), 5-C-benzhydryl-(3a) and 3,5-di-C-benzhydryl-(2a) derivatives in 19.7, 14.8 and 6.7percent yields respectively.Location of benzhydryl unit in 3a and 4a has been made (i) by NOE studies and (ii) by converting them into 7d and 8d respectively via 3b and 4b and comparing them with authentic 7d and 8d prepared by benzhydrylation of 5,7-dihydroxychromone (5) followed by methylation of the products (7a and 8a).Locationof benzhydryl unit in 7a and 8a can be made by comparing the PMR spectra of their methyl ethers and acetates
- Jain, A. C.,Gupta, S. M.,Bambah, Pawan
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p. 393 - 397
(2007/10/02)
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- Synthesis and Taste of Some Flavanone and Dihydrochalone Glycosides in which Carbohydrate Moieties are Located at differing Positions of the Aglycones
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To clarify the influence upon taste of the sugar position in the aglycone of dihydrochalcone (DHC), new nine DHC glycosides were synthesized: naringin DHC 4-O-β-D-glucopyranoside (I), naringin DHC 4-O-β-D-galactopyranoside (II), naringin DHC 4-O-β-D-xylopyranoside (III), 3,2',3'-trihydroxy-4-methoxy DHC 3'-O-β-D-galactopyranoside (XII), 3,2',4'-trihydroxy-4-methoxy DHC 4'-O-β-D-galactopyranoside (XIII), 3,2',5'-trihydroxy-4-methoxy DHC 5'-O-β-D-galactopyranoside (XIV), 3,2',6'-trihydroxy-4-methoxy DHC 6'-O-β-D-glactopyranoside (XV), 3,2',4',6'-tetrahydroxy-4-methoxy DHC 2',4'-O-β-digalactopyranoside (XVI) and 3,2',4'-trihydroxy-4-methoxy DHC 4'-O- (XL).Such compounds as I, II and III which carry the sugars in both the A and B rings of the DHC's were completely tasteless.Between XII, XIII, XIV, XV, XVI and XL, XIII and XL were 140 and 400 times sweeter than sucrose and the remainder were either slightly sweet, tasteless or bitter.
- Konishi, Fukuko,Esaki, Sachiko,Kamiya, Shintaro
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p. 1419 - 1430
(2007/10/02)
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