Studies of the Selective O-Alkylation and Dealkylation of Flavonoids. XXIV. A Convenient Method for Synthesizing 6- and 8-Methoxylated 5,7-Dihydroxyisoflavones.

Hòrie, Tokunaru; Shibata, Kenichi; Yamashita, Kazuyo; Fujii, Kouji; Tsukayama, Masao; Ohtsuru, Yoshizumi

doi:10.1248/cpb.46.222

Cited by 29 publications

(20 citation statements)

References 2 publications

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“…A characteristic singlet resonance for H-2 of isoflavone was observed at d H 8.15 (Horie et al 1998). This assignment was confirmed by its long-range connectivity to the quaternary carbons at d C 178.1 (C-4), 159.1 (C-9), 126.2 (C-3) and 124.0 (C-1 0 ) in the HMBC spectrum.…”

Section: Resultsmentioning

confidence: 98%

Two new isoflavone 7-O-α-4″-anhydro-4″,5″-didehydroglucuronides from Streptomyces sp. LZ35ΔgdmAI

Deng

Chen

2015

Natural Product Research

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Two isoflavone 7-O-α-4″-anhydro-4″,5″-didehydroglucuronides, namely daidzein 7-O-α-4″-anhydro-4″,5″-didehydroglucuronide (1) and genistein 7-O-α-4″-anhydro-4″,5″-didehydroglucuronide (2), were isolated and identified from the mutant strain of Streptomyces sp. LZ35ΔgdmAI. Their structures were elucidated by the analysis of their high resolution mass spectrometry (HR-MS) and 1D, 2D Nuclear magnetic Resonance (NMR) spectroscopic data. They are new natural products and maybe the transformed products of the soybean meal by Streptomyces sp. LZ35ΔgdmAI.

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Section: Resultsmentioning

confidence: 98%

Two new isoflavone 7-O-α-4″-anhydro-4″,5″-didehydroglucuronides from Streptomyces sp. LZ35ΔgdmAI

Deng

Chen

2015

Natural Product Research

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“…The triterpenoids were readily identified as lupeol ( 1 ), lupenone ( 2 ), 28-hydroxylup-20(29)-en-3-one ( 3 ) and betulin ( 4 ) [ 4 , 6 , 7 , 8 ] by a GC-MS library search. Isoflavonoids were identified by comparison with literature data and descriptions as 8- O -methylretusin (7-hydroxy-8,4’-dimethoxyisoflavone) ( 5 ) [ 9 , 10 ], 7-hydroxy-5,6,4’-trimethoxyisoflavone ( 6 ) [ 11 , 12 ], afrormosin (7-hydroxy-6,4’-dimethoxyisoflavone) ( 8 ) [ 13 ], 7-hydroxy-8,3’,4’-trimethoxyisoflavone ( 9 ) [ 14 ], 7,3’-dihydroxy-8,4’-dimethoxyisoflavone ( 10 ) [ 14 , 15 ], odoratin (7,3’-dihydroxy-6,4’-dimethoxyisoflavone) ( 11 ) [ 16 ], 7,8,3’-trihydroxy-4’-methoxyisoflavone ( 13 ) [ 17 ], 7,8,3’-trihydroxy-6,4’-dimethoxy-isoflavone ( 15 ) [ 18 ], dipteryxin (7,8-dihydroxy-6,4’-dimethoxyisoflavone) ( 17 ) [ 15 ]. The chalcone was identified as isoliquiritigenin (4,2’,4’-trihydroxychalcone) ( 7 ) [ 19 ], the aurone as sulfuretin (6,3’,4’-trihydroxyaurone) ( 14 ) [ 20 ], and the phenolic compounds as vanillic acid ( 12 ) [ 21 ], vanillin ( 16 )[ 21 ], and protocatechuic acid ( 18 ) [ 22 ].…”

Section: Resultsmentioning

confidence: 99%

Chemical Constituents of the Bark of Dipteryx alata Vogel, an Active Species against Bothrops jararacussu Venom

et al. 2010

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The effect of four sub-extracts prepared from the lyophilized hydroalcoholic bark of Dipteryx alata (Leguminosae-Papilionoideae) dissolved in a methanol-water (80:20) mixture through a liquid-liquid partition procedure has been investigated against the neuromuscular blockade of the venom of the snake Bothrops jararacussu. The active CH2Cl2 sub-extract has been extensively analyzed for its chemical constituents, resulting in the isolation of four lupane-type triterpenoids: lupeol (1), lupenone (2), 28-hydroxylup-20(29)-en-3-one (3), betulin (4), nine isoflavonoids: 8-O-methylretusin (5), 7-hydroxy-5,6,4’-trimethoxyisoflavone (6), afrormosin (8), 7-hydroxy-8,3’,4’-trimethoxyisoflavone (9), 7,3’-dihydroxy-8,4’-dimethoxyisoflavone (10), odoratin (11), 7,8,3’-trihydroxy-4’-methoxyisoflavone (13), 7,8,3’-trihydroxy-6,4’-dimethoxyisoflavone (15), dipteryxin (17), one chalcone: isoliquiritigenin (7), one aurone: sulfuretin (14) and three phenolic compounds: vanillic acid (12), vanillin (16), and protocatechuic acid (18). Their chemical structures were elucidated on the basis of spectroscopic analysis, including HRMS, 1D- and 2D-NMR techniques.

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“…The reason depends on the number of the electron-releasing subtituents in the B-ring. 12,21) The coupling reaction of 27 with 2-methyl-3-butyn-2-ol in the presence of Pd(0) gave 6-(3-hydroxy-3-methyl-1-butynyl)isoflavone 28 in 57% yield. The catalytic hydrogenation of 28 over Pd/C gave 4Ј,5,7-trihydroxy-6-(3-hydroxy-3-methylbutyl)isoflavone (3) in 92% yield.…”

Section: Resultsmentioning

confidence: 99%

Regioselective Synthesis of 6-Alkyl- and 6-Prenylpolyhydroxyisoflavones and 6-Alkylcoumaronochromone Derivatives

Tsukayama

Wada

Kawamura

et al. 2004

CHEMICAL & PHARMACEUTICAL BULLETIN

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Prenyl (ϭ3-methyl-2-butenyl)isoflavones and (3-hydroxy-3-methylbutyl)isoflavones, which contain an alkyl or alkenyl group in the A-and/or B-ring, are widely distributed in nature and have antifungal activity. [1][2][3][4] Luteone, known as a phytoalexin, was first isolated in 1973 from immature fruits of Lupinus luteus (Leguminosae).5) The structure was assigned as 2Ј,4Ј,5,7-tetrahydroxy-6-(3-methyl-2-butenyl)isoflavone (1) by spectroscopic and chemical studies. The same isoflavone 1 was also isolated from healthy leaves or roots of white lupin (Lupinus albus L., cv Kievskij Mutant) 4,6) and the roots of yellow lupin (Lupinus leuteus L., cv. Barpin) together with luteone hydrate, the structure of which was assigned to be 2Ј,4Ј,5,7-tetrahydroxy-6-(3-hydroxy-3-methylbutyl)isoflavone (2) by spectroscopic analysis.7) Luteone hydrate (2) was isolated as a fungal metabolite of luteone (1) with cultures of Aspergillus flavus and Botrytis cinerea. 8)Wighteone hydrate [4Ј,5,7-trihydroxy-6-(3-hydroxy-3-methylbutyl)isoflavone] (3) was also isolated as a fungal metabolite of wighteone [4Ј,5,7-trihydroxy-6-(3-methyl-2-butenyl)isoflavone] 2,6,7,9) with cultures of A. flavus and B. cinerea. 10) In view of the isolation of 1 and 2 from the same natural source, it is considered that 2 is a precursor of 1 and dehydration of 2 would lead to 1. The total syntheses of isoflavones 1, 2, and 3 have not been achieved yet, although the dimethyl ether of luteone (1) has been synthesized.11) The reason seems to be due to the difficulty in introducing an alkyl or alkenyl group regioselectively into the isoflavone nucleus and the selectivity of protection and consequent deprotection. Furthermore, 6-alkylpolyhydroxyisoflavones are isomerized to the corresponding isomers, 8-alkylpolyhydroxyisoflavones, by bases.12,13) We need to solve these problems for the regioselective synthesis of these phloroglucin-type 6-prenylisoflavones. In our previous paper, 14) we reported the regioselective synthesis of prenylisoflavones. As a continuation of our studies on the regioselective synthesis of alkyl-and prenylisoflavones, we wish to report here on the first syntheses of 1, 2, and 3 using the palladium (0)-catalyzed coupling reaction 15) of the corresponding iodoisoflavone with 2-methyl-3-butyn-2-ol.16) Recently, the new coumaronochromones (ϭbenzofuro [2,3-b][1]benzopyran-11-ones) lupilutin (8-alkylcoumaronochromone from the root of yellow lupin) 7) and lupinalbin B (6-prenylcoumaronochromone from the root of white lupin) 17) have also been isolated. However, 6-alkylcoumaronochromone (4), which is considered to be a precursor of lupinalbin B, has yet to be isolated from natural sources. We have examined the simple and general applicability of DDQ or o-chloranil to the synthesis of alkylpolyhydroxycoumaronochromones from the corresponding 2Ј-hydroxyisoflavones. 18) We wish to report here the synthesis of compound 4 by oxidative cyclization of compound 2 with ochloranil. Results and DiscussionThe catalytic hydrogenation of 2Ј,4Ј-bis(benzyloxy)-6Ј-methoxym...

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Studies of the Selective O-Alkylation and Dealkylation of Flavonoids. XXIV. A Convenient Method for Synthesizing 6- and 8-Methoxylated 5,7-Dihydroxyisoflavones.

Cited by 29 publications

References 2 publications

Two new isoflavone 7-O-α-4″-anhydro-4″,5″-didehydroglucuronides from Streptomyces sp. LZ35ΔgdmAI

Two new isoflavone 7-O-α-4″-anhydro-4″,5″-didehydroglucuronides from Streptomyces sp. LZ35ΔgdmAI

Chemical Constituents of the Bark of Dipteryx alata Vogel, an Active Species against Bothrops jararacussu Venom

Regioselective Synthesis of 6-Alkyl- and 6-Prenylpolyhydroxyisoflavones and 6-Alkylcoumaronochromone Derivatives

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