- Daidzein as an antioxidant of lipid: Effects of the microenvironment in relation to chemical structure
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Isoflavone daidzein (D, pKa1 = 7.47 ± 0.02 and pK a2 = 9.65 ± 0.07) was, through a study of the parent compound and its three methyl anisol derivatives 7-methyldaidzein (7-Me-D, pKa = 9.89 ± 0.05), 4'-methyldaidzein (4'-Me-D, pKa = 7.43 ± 0.03), and 7,4'-dimethyldaidzein (7,4'-diMe-D), found to retard lipid oxidation in liposomal membranes through two mechanisms: (i) radical scavenging for which the 4'-OH was more effective than the 7-OH group in agreement with the oxidation potentials: 0.69 V for 4'-OH and 0.92 V for 7-OH versus Ag/AgCl in acidic solution and 0.44 V for 4'-O- and 0.49 V for 7-O- in alkaline solution and (ii) change in membrane fluidity through incorporation of the isoflavones, in effect hampering radical mobility. The radical scavenging efficiency measured by the rate of the reaction with the ABTS?+ in aqueous solution followed the order D > 7-Me-D > 4'-Me-D > 7,4'-diMe-D, as also found for antioxidant efficiency in liposomes when oxidation was initiated with the water-soluble AAPH radical and monitored as the formation of conjugate dienes. For oxidation initiated by the lipid-soluble AMVN radical, the antioxidant efficiency was ranked as 4'-Me-D > D > 7,4'-diMe-D > 7-Me-D, and change in fluorescence anisotropy of fluorescent probes bound to the membrane surface or inside the lipid bilayer confirmed the effects of isoflavones on the membrane fluidity, especially for 7,4'-diMe-D.
- Liang, Jun,Tian, Yu-Xi,Fu, Li-Min,Wang, Tian-He,Li, Hai-Jun,Wang, Peng,Han, Rui-Min,Zhang, Jian-Ping,Skibsted, Leif H.
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- Hydrogen bonds and π-π stacking interaction in 4′, 7-dimethoxylisoflavone and 4′,7-diacetyl-O-isoflavone
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4′,7-dimethoxylisoflavone, C17H14O4, (I), is linked into a supramolecular structure by a variety of weak but direction-specific intermolecular forces, the molecules are linked into chains through C-H...O hydrogen bonds, th
- Zhang, Zun-Ting,Wang, Xiao-Bing,Wang, Qiu-Ya,Wu, Li-Na
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- ISOFLAVONE O-METHYLTRANSFERASE ACTIVITIES IN ELICITOR-TREATED CELL SUSPENSION CULTURES OF MEDICAGO SATIVA
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Treatment of alfalfa cell suspension cultures with elicitor preparations from baker's yeast or from cell walls of Colletotrichum lindemuthianum resulted in a ca 200-fold induction of isoflavone O-methyltransferase (IOMT) activity.The elicited cultures contained O-methyltransferase activity against isoflavone, isoflavan and pterocarpan substrates.These activities could be separated into two distinct fractions by ion-exchange chromatography.The major IOMT activity (IOMT II) was purified to homogeneity by a combination of anion exchange chromatography, hydrophobic interaction chromatography and chromatofocussing.It is a monomeric enzyme of subunit Mr 41000 which could be photoaffinity labelled with tritiated SAM.IOMT II converted the isoflavone daidzein to its 7-O-methyl ether isoformononetin, with Km values of 20 μM for daidzein and 150 μM for SAM and a pH optimum of 8.5.Both IOMT II and the less abundant IOMT species (IOMT I) exhibited greatest activity with 6,7,4'-trihydroxyisoflavone as methyl acceptor.IOMT I, but not IOMT II, also catalysed the A-ring methylation of the pterocarpan phytoalexin medicarpin.Isoflavone 4'-OMT activity, which is believed necessary for the formation of the B-ring methoxy substituent of medicarpin, was present at very low activity in extracts from the cultures and was only weakly induced by elicitor.Key Word Index - Medicago sativa; Leguminosae; isoflavone 7-O-methyltransferase; phytoalexin biosynthesis
- Edwards, Robert,Dixon, Richard A.
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- Synthesis of isoflavones via base catalysed condensation reaction of deoxybenzoin
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Base catalysed condensation reaction of o-hydroxyl-α- phenylacetophenones with formyl reagents affords various substituted isoflavones. Many bases were tested in the condensation reaction and DMAP was found to be the most effective catalysis.
- Li, Wanmei,Liu, Fangming,Zhang, Pengfei
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- An efficient synthesis of daidzein, dimethyldaidzein, and isoformononetin
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Synthesis of the soy isoflavone, daidzein, and its derivatives, isoformononetin and dimethyldaidzein, through utilization of a novel synthetic pathway is reported. This synthesis employs an enamine addition and O-methylation of 2,4-dihydroxyacetophenone, a subsequent ring closure and iodination, followed by a Suzuki coupling with PEG 10000. Demethylation of either isoformononetin or dimethyldaidzein afforded daidzein.
- Biegasiewicz, Kyle F.,Denis, Jeffrey D. St.,Carroll, Vincent M.,Priefer, Ronny
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Read Online
- Synthesis of isoflavones from 2′-hydroxychalcones using poly[4-(diacetoxy)iodo]styrene or related hypervalent iodine reagent
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Isoflavones are synthesized in an one-pot reaction by treating the hypervalent iodine(III) reagent, [hydroxy(tosyloxy)iodo]benzene (HTIB, Koser's reagent) with 2′-benzoyloxychalcones in MeOH. A combined use of (diacetoxyiodo)benzene (DIB)/p-toluenesulfoni
- Kawamura, Yasuhiko,Maruyama, Masashi,Tokuoka, Takanori,Tsukayama, Masao
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- Enantioselective Synthesis of Isoflavanones and Pterocarpans through a RuII-Catalyzed ATH-DKR of Isoflavones
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Noyori-Ikariya RuII complexes promoted the one-pot C=C/C=O bonds reduction of isoflavones using sodium formate as the hydrogen source through Asymmetric Transfer Hydrogenation-Dynamic Kinetic Resolution (ATH-DKR). Due to the neutral conditions employed, isoflavones with different substituents at the 2’-position of B-ring (H, OH, OMe and Br) were successfully reduced. Ten cis-3-phenylchroman-4-ols were selectively obtained (>20 : 1 dr) in good yields (up to 86 %) and excellent enantioselectivities (up to >99 : 1 er). The synthetic applications of these chiral compounds were also demonstrated. Enantioenriched isoflavanones were obtained under mild metal-free oxidation of the cis-3-phenylchroman-4-ols while pterocarpans were synthesized by two strategies: an acid-catalyzed cyclization and a novel approach based on a Pd-catalyzed C?O intramolecular cross-coupling reaction.
- Caleffi, Guilherme S.,Costa, Paulo R. R.,Costa-Júnior, Paulo C. T.,Gaspar, Francisco V.
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p. 5097 - 5108
(2021/10/20)
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- Stille coupling for the synthesis of isoflavones by a reusable palladium catalyst in water
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Isoflavones were synthesized from the reaction of 3-bromochromone derivatives and aryltributylstannanes via Stille coupling catalyzed by a water-soluble and reusable PdCl2(NH3)2/2,2′-cationic bipyridyl system in aqueous solution. For prototype 3-bromochromone, the coupling reaction was performed at 80°C for 24 hr with 2.5 mol% catalyst in water in the presence of tetrabutylammonium fluoride. After the reaction, the aqueous solution could be reused for several runs, indicating that its activity was only slightly decreased. For substituted 3-bromochromones, the addition of NaHCO3 and a higher reaction temperature (120°C) were required to gain satisfactory outcomes. In addition, naturally occurring products, such as daidzein, could be obtained by this protocol via a one-pot reaction.
- Chang, Ya-Ting,Liu, Ling-Jun,Peng, Wen-Sheng,Lin, Lin-Ting,Chan, Yi-Tsu,Tsai, Fu-Yu
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p. 469 - 475
(2021/02/03)
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- Synthesis method of 3 ', 4', 7-trihydroxy isoflavone
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The invention discloses a synthesis method of 3', 4', 7-trihydroxy isoflavone. The method comprises the steps that 4', 7-dimethoxyisoflavone and bromine are subjected to a mixed reaction in a dichloromethane medium to obtain 3'-bromo-4 ', 7-dimethoxyisoflavone, wherein the molar ratio of 4', 7-dimethoxyisoflavone to bromine is 1: 1.1-1.5, and the reaction temperature is 20-30 DEG C; the 3'-bromo-4', 7-dimethoxyisoflavone reacts with sodium methoxide under the action of cuprous salt to obtain 3', 4', 7-trimethoxyisoflavone; and the 3', 4', 7-trimethoxyisoflavone is demethylated to obtain the 3', 4', 7-trihydroxy isoflavone. Compared with the prior art, the method has the advantages of abundant sources of initial raw materials, mild reaction conditions, high selectivity and high yield, and is suitable for industrial production.
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Paragraph 0030; 0033-0036
(2020/09/09)
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- Synthetic method of polyhydroxy isoflavone
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The invention discloses a synthetic method of polyhydroxy isoflavone. The method comprises the following steps: (1) reacting 4', 7-dimethoxyisoflavone with N-bromosuccinimide, and controlling the molar ratio of 4', 7-dimethoxyisoflavone to N-bromosuccinimide and a reaction temperature to enable one or two hydrogen atoms on a 4', 7-dimethoxyisoflavone carbon ring to be substituted by bromine atomsto generate corresponding bromide; (2), enabling the bromide in the (2) to react with sodium methoxide under the action of cuprous salt to enable bromine atoms on a carbon ring of the bromide to be substituted by methoxy to obtain a methoxylation product; and (3), carrying out a demethylation reaction on the methoxylation product obtained in the (3) under the action of aluminum chloride and dimethyl sulfide to obtain polyhydroxy isoflavone. The method has the advantages of abundant sources of initial raw materials, mild reaction conditions, good selectivity and high yield, and is suitable forindustrial production. The purity of the product is greater than 99.0%, and the product can be used for pharmacological activity research.
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Paragraph 0041-0043
(2020/09/09)
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- Transient and Recyclable Halogenation Coupling (TRHC) for Isoflavonoid Synthesis with Site-Selective Arylation
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A transient and recyclable C?H iodination has been designed for the synthesis of isoflavonoids through the domino reactions of o-hydroxyphenyl enaminones and aryl boronic acids in the presence of catalytic KI and Pd catalyst. Instead of the conventional cross-coupling strategy employing pre-halogenated substrates, this method transforms raw C?H bond by means of a transient C?H halogenation to smoothly relay the subsequent C-arylation. Consequently, such a method avoids the pre-functionalization for C?halogen bond installation as well as the generation of stoichiometric halogen-containing waste following the cross-coupled product, disclosing an intriguing new coupling protocol to forge the C?C bond in the virgin area between classical C?X (X=halogen) bond cross coupling and the C?H activation.
- Wan, Jie-Ping,Tu, Zhi,Wang, Yuyun
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supporting information
p. 6907 - 6910
(2019/05/10)
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- Pot-economic synthesis of diarylpyrazoles and pyrimidines involving Pd-catalyzed cross-coupling of 3-trifloxychromone and triarylbismuth
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Abstract: The present study reveals the formation of 3,4-diarylpyrazole and 4,5-diarylpyrimidine in one-pot operation starting from 3-trifloxychromone and triarylbismuth. The complete process encompasses two steps in the one-pot operation. The first step leads to the formation of isoflavone via cross-coupling reaction of 3-trifloxychromone and triarylbismuth as a threefold arylating reagent. These isoflavones were further converted into 3,4-diarylpyrazole and 4,5-diarylpyrimidine using hydrazine hydrate and guanidinium chloride in the successive step in the same pot. Interestingly the formation of 3,4-diarylpyrazole was achieved in the shortest reaction time i.e., 30 min that too at room temperature. Overall the developed methodology provides easy access to the medicinally important diarylpyrazole and pyrimidine moiety in one-pot operation and in short reaction time. Graphical Abstract: Synopsis The work presented here describes the novel methodology for the formation of medicinally important heterocycles 3,4-diarylpyrazole and 4,5-diarylpyrimidine in one-pot operation starting from 3-trifloxychromone and triarylbismuth.
- Kumar, Abhijeet,Rao, Maddali L N
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- Enantioselective Synthesis of Isoflavanones by Catalytic Dynamic Kinetic Resolution
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A ruthenium-catalyzed asymmetric transfer hydrogenation of racemic isoflavanones with dynamic kinetic resolution yields virtually enantiopure isoflavanols as single diastereomers. Subsequent oxidation gives rise to isoflavanones in high enantiomeric purit
- Qin, Tao,Metz, Peter
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supporting information
p. 2981 - 2984
(2017/06/07)
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- Development of 3-alkyl-6-methoxy-7-hydroxy-chromones (AMHCs) from natural isoflavones, a new class of fluorescent scaffolds for biological imaging
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Starting from 7-hydroxyisoflavones, we developed a new class of fluorescent scaffolds, 3-alkyl-6-methoxy-7-hydroxy-chromones (AMHCs, MW ～ 205.19, λab ～ 350 nm, λem ～ 450 nm) via a trial and error process. AMHCs have the advantages of being a small molecular moiety, having strong fluorescence in basic buffers, reasonable solubility and stability, non-toxicity, and are conveniently linked to pharmacophores. AMHCs were successfully used in fluorescence microscopy imaging of cells and tissues. This journal is
- Miao, Jianzhuang,Cui, Huaqing,Jin, Jing,Lai, Fangfang,Wen, Hui,Zhang, Xiang,Ruda, Gian Filippo,Chen, Xiaoguang,Yin, Dali
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supporting information
p. 881 - 884
(2015/02/19)
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- A Concise Synthesis of Pyrazole Analogues of CombretastatinA1 as Potent Anti-Tubulin Agents
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CombretastatinA1 (CA1) binds to the β-subunit at the colchicine binding site of tubulin and inhibits polymerization. As such, it is both an antitumor agent and a vascular disrupting agent. It has been shown to be at least tenfold more potent than combreta
- Zaninetti, Roberta,Cortese, Salvatore V.,Aprile, Silvio,Massarotti, Alberto,Canonico, Pier Luigi,Sorba, Giovanni,Grosa, Giorgio,Genazzani, Armando A.,Pirali, Tracey
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p. 633 - 643
(2013/08/22)
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- Novel synthesis of 3-phenyl-chromen-4-ones using n-heterocyclic carbene as organocatalyst: An efficient domino catalysis type approach
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Herein is reported a simple and efficient synthesis of isoflavones starting from various substituted phenacyl bromides and salicylaldehydes in presence of NHC. The mechanism involved domino catalysis type approach with consumption and regeneration of catalyst in two catalytic cycles. This method proved to be very lucrative and gives very good yield. The method described here represents an environmentally benign alternative to classical approach.
- Mishra, Priya,Singh, Sarita,Ankit, Preyas,Fatma, Shahin,Singh, Divya,Singh, Jagdamba
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p. 1070 - 1076
(2013/07/28)
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- Synthetic analogs of daidzein, having more potent osteoblast stimulating effect
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A series of didzein derivatives were synthesized and assessed for stimulation of osteoblast differentiation using primary cultures of rat calvarial osteoblasts. Data suggested that three synthetic analogs, 1c, 3a and 3c were several folds more potent than daidzein in stimulating differentiation and mineralization of osteoblasts. Further, these three compounds did not show any estrogen agonistic activity, however had mild estrogen antagonistic effect. Out of the three compounds, 3c was found to maximally increase the mineralization of bone marrow osteoprogenitor cells. Compound 3c also robustly increased the mRNA levels of osteogenic genes including bone morphogenetic protein-2 and osteocalcin in osteoblasts. Unlike daidzein, 3c did not inhibit osteoclastogenesis. Collectively, we demonstrate osteogenic activity of daidzein analogs at significantly lower concentrations than daidzein.
- Yadav, Dinesh K.,Gautam, Abnish K.,Kureel, Jyoti,Srivastava, Kamini,Sahai, Mahendra,Singh, Divya,Chattopadhyay, Naibedya,Maurya, Rakesh
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supporting information; experimental part
p. 677 - 681
(2011/03/18)
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- Reaction of natural isoflavonoids and their analogs with hydroxylamine
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Recyclization of the chromone ring in several natural isoflavonoids and their analogs by reaction with hydroxylamine was studied. It has been found that the most suitable base for carrying out the reaction is N-methylmorpholine. Several derivatives of 4-a
- Bondarenko,Frasinyuk,Khilya
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p. 402 - 407
(2008/03/14)
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- Benzoxazepine derivatives as selective estrogen receptor modulators
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The present invention is directed to novel benzoxazepine derivatives, pharmaceutical compositions containing them and their use in the treatment of disorders and diseases mediated by an estrogen receptor.
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Page/Page column 6
(2008/06/13)
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- Biotransformation of isoflavones by the larvae of the common cutworm (Spodoptera litura)
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Biotransformation of the 5,7,4′-trimethoxyisoflavone (1), 6,7,4′-trimethoxyisoflavone (2), and 7,4′-dimethoxyisoflavone (3) by insects, Spodoptera litura was investigated. Compound 1 was transformed to 5-hydroxy-7,4′-dimethoxyisoflavone (4), 7-hydroxy-5,4
- Takahashi, Koji,Araki, Hideo,Miyazawa, Mitsuo
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p. 719 - 721
(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 115
(2010/02/15)
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- Synthesis of isoflavones containing naturally occurring substitution pattern by oxidative rearrangement of respective flavanones using thallium(III) p-tosylate
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Claisen condensation of substituted 2′-hydroxyacetophenones 1a-c with aromatic aldehydes affords respective substituted 2′-hydroxychalcones 2a-n which on base catalyzed cyclization in pyridine:methanol:water (1:1:1) give respective flavanones 3a-n. The oxidative rearrangement of flavanones with thallium(III) p-tosylate furnishes respective isoflavones 4a-n in overall 62-72% yields starting from 1. The present methodology has been successfully applied for the synthesis of naturally occurring isoflavones such as di-O-methyldaidzein 4a, cabruvin 4b, pseudobabtigenin methylether 4d, 5,7-dimethoxyisoflavone 4f, 5,7,4′-trimethoxyisoflavone 4g, derrustone 4i, 7,8,3′,4′- tetramethoxyisoflavone 41, purpuranin-A 4m and 7,8,3′,4′,5′- pentamethoxyisoflavone 4n and thus the first synthesis of 4n is reported.
- Singh, Om V.,Muthukrishnan,Sunderavadivelu
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p. 2575 - 2581
(2007/10/03)
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- COMPOUNDS USEFUL FOR THE INHIBITION OF ALDH
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The present invention provides novel antidipsotropic compounds. The invention further provides methods of inhibiting ALDH-2 using the compounds described herein. Methods for modulating alcohol consumption, alcohol dependence and/or alcohol abuse by administering the compounds of the invention to an individual are also provided. The present invention further provides a rationale for designing additional novel antidipsotropic compounds.
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Page/Page column 35
(2010/11/30)
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- Synthesis of daidzin analogues as potential agents for alcohol abuse
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Daidzin, the active principle of an herbal remedy for 'alcohol addiction', has been shown to reduce alcohol consumption in all laboratory animals tested to date. Correlation studies using structural analogues of daidzin suggests that it acts by raising the monoamine oxidase (MAO)/mitochondrial aldehyde dehydrogenase (ALDH-2) activity ratio (J. Med. Chem. 2000, 43, 4169). Structure-activity relationship (SAR) studies on the 7-O-substituted analogues of daidzin have revealed structural features important for ALDH-2 and MAO inhibition (J. Med. Chem. 2001, 44, 3320). We here evaluated effects of substitutions at 2, 5, 6, 8, 3′ and 4′ positions of daidzin on its potencies for ALDH-2 and MAO inhibition. Results show that analogues with 4′-substituents that are small, polar and with hydrogen bonding capacities are most potent ALDH-2 inhibitors, whereas those that are non-polar and with electron withdrawing capacities are potent MAO inhibitors. Analogues with a 5-OH group are less potent ALDH-2 inhibitors but are more potent MAO inhibitors. All the 2-, 6-, 8- and 3′-substituted analogues tested so far do not inhibit ALDH-2 and/or have decreased potencies for MAO inhibition. This, together with the results obtained from previous studies, suggests that a potent antidipsotropic analogue would be a 4′,7-disubstituted isoflavone. The 4′-substituent should be small, polar, and with hydrogen bonding capacities such as, -OH and -NH2; whereas the 7-substituent should be a straight-chain alkyl with a terminal polar function such as -(CH 2)n-OH with 2≤n ≤6, -(CH2) n-COOH with 5≤n ≤10, or -(CH2)n-NH 2 with n ≥4.
- Gao, Guang-Yao,Li, Dian-Jun,Keung, Wing Ming
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p. 4069 - 4081
(2007/10/03)
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- The first isolation and crystal structure of a boron difluoro complex (isoflavone yellow). Biologically active intermediates produced during isoflavone synthesis
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The yellow intermediate 4f produced during the reaction of the deoxybenzoin 3f with N,N'-dimethyl(chloromethylene)ammonium chloride in the presence of BF3*Et2O prior to the formation of the corresponding isoflavone was isolated for the first time and characterized by NMR, MS and single-crystal X-ray diffraction techniques. These yellow intermediates showed anticancer, nematicidal and mosquitocidal activities.
- Balasubramanian, Sreenivasan,Ward, Donald L.,Nair, Muraleedharan G.
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p. 567 - 570
(2007/10/03)
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- An efficient 'one pot'synthesis of isoflavones
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Initial formation of deoxybenzoin 3 from phenyl acetic acid 1 and phenol 2 in the presence of BF3.Et2O followed by its treatment at room temperature with N, N'-dimethyl (chloromethylene) ammonium chloride, generated by reacting PCl5 with DMF provides a mild and efficient route for a 'one pot' synthesis of Isoflavones in high yields.
- Balasubramanian, Sreenivasan,Nair, Muraleedharan G.
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p. 469 - 484
(2007/10/03)
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- Organolead-mediated Arylation of Allyl β-Ketoesters: A Selective Synthesis of Isoflavanones and Isoflavones
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Arylation of A-ring substituted and unsabstituted 3-allyloxycarbonylchroman-4-ones with aryllead(IV) triacetates followed by selective catalytic deallyloxycarbonylation affords isoflavanones or isoflavones in high overall yields.The highest yield in the arylation step was observed in the reaction of 5,7-dimethoxychroman-4-one with the more hindered 2,4,6-trimethoxyphenyllead triacetate.
- Donnelly, Dervilla M.,Finet, Jean-Pierre,Rattigan, Bernard A.
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p. 1729 - 1736
(2007/10/02)
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- Aryllead mediated synthesis of isoflavanone and isoflavone derivatives
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The reaction of aryllead (IV) triacetates with 3-(phenylthio)-chroman-4-one and 2-p-methoxyphenyl-3-(phenylthio)-chroman-4-one derivatives was carried out in chloroform in presence of pyridine to afford moderate to quantitative yields of the corresponding hindered 3-aryl-3-phenylthiochroman-4-one derivatives. Removal of the phenylthio group by oxidation with dimethyldioxirane led to the corresponding isoflavones and 2-p-methoxyphenylisoflavones, and by reduction with a large excess of nickel boride to the isoflavanones and 2-(4′-anisyl)-isoflavanones respectively. In the 2-p-methoxyphenyl series the nickel boride reduction of the compounds bearing ortho-substituted 3-aryl groups gave the chalcones which were recyclised under basic catalysis.
- Donnelly, Dervilla M. X.,Fitzpatrick, Brendan M.,O'Reilly, Bernadette A.,Finet, Jean-Pierre
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p. 7967 - 7976
(2007/10/02)
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- ENANTIOSELECTIVE SYNTHESIS OF FLAVONOIDS. PART 1. POLY-OXYGENATED CHALCONE EPOXIDES
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Epoxidation of a series of poly-oxygenated chalcones with H2O2 in the presence of poly-α-aminoacid catalysts afforded chiral aromatic oxygenated epoxides in moderate to high optical yields; their absolute configurations were determined by CD spectroscopy.These chalcone epoxides could, in principle, be used as chirons for enantiomerically enriched dihydroflavonols.
- Augustyn, Jan A. N.,Bezuidenhoudt, Barend C. B.,Ferreira, Daneel
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p. 2651 - 2660
(2007/10/02)
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- ONE-STEP CONVERSION OF FLAVANONES INTO ISOFLAVANONES: A NEW FACILE BIOMIMETIC SYNTHESIS OF ISOFLAVONES
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One-step chemical conversion of flavanones into isoflavones by use of thallium trinitrate (TTN) is reported, and the mechanism of a 2,3-aryl migration in this reaction is discussed in relation to in vivo rearrangement process of flavanone precursors in the isoflavone biosynthesis.
- Kinoshita, Takeshi,Ichinose, Koji,Sankawa, Ushio
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p. 7355 - 7356
(2007/10/02)
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- Acid-catalysed Coupling Reactions and Conversions of Isoflavone Epoxides
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Whereas 4',7-dimethoxy- (5) and 4'-methoxy-2',7-ditosyloxy-isoflavone epoxides (7) are subject to regioselective acid-mediated methanolysis to yield 2-hydroxy-3-methoxy- and 3-hydroxy-2-methoxy-isoflavanones, the 2',7-dibenzyloxy-4'-methoxy analogue (6) i
- Bezuidenhoudt, Barend C. B.,Brandt, E. Vincent,Ferreira, Daneel
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p. 1081 - 1088
(2007/10/02)
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- Flavonoid synthesis based on photolysis of flavan-3-ols, 3-hydroxyflavanones, and 2-benzylbenzofuranones
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Irradiation of flavan-3-ols, 3-hydroxyflavanones, and 2-benzylbenzofuranones in methanol leads mainly to photochemical opening of the heterocyclic ring, or to its complete photofragmentation, the products being trapped by reaction with the solvent. Fission of exocyclic C-O bonds also occurs, accompanied by intramolecular rearrangements. The course of these reactions is often dependent on the position and nature of substituents. The conversions provide novel routes to 1,3-diaryl-1-methoxypropan-2-ols, 1,3-diaryl-2,2-dimethoxypropan-1-ones, cis-3-methoxyflavanones, isoflavones, flavanones, and trans-chalcones, and hence to α-hydroxychalcones, cis- and trans-α-methoxychalcones, and 2-methoxy-2-(α-methoxybenzyl)benzofuranones.
- Fourie, Theunis G.,Ferreira, Daneel,Roux, David G.
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p. 125 - 133
(2007/10/07)
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