13C NMR spectra of polymethoxy‐ and methylenedioxyflavonols

Calvert, David J.; Cambie, R. C.; Davis, B. R.

doi:10.1002/mrc.1270121008

Cited by 46 publications

(31 citation statements)

References 27 publications

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“…After chromatographic separation, the remaining fractions from the extraction and isolation previously described 7) yielded six already known compounds-5-hydroxy-3,6,7-tri methoxy-3′,4′-methylenedioxyflavone (melisimplin) (7), 8) 5,7-di hydroxy-3,3′,4′,8-tetra methoxy flavone (8), 9,10) 4′,5-dihydro xy-3,3′,7,8-tetramethoxyflavone (ternatin) (9), 11) 3,5,6,7,8-penta methoxy-3′,4′-methyl enedioxyflavone (melibenRegular Article * To whom correspondence should be addressed. e-mail: matuhiga@sci.u-ryukyu.ac.jp…”

Section: Resultsmentioning

confidence: 99%

“…It also exhibited a peak of another methoxy carbon at 61.0 ppm, and the peak was assigned to the 3-methoxy group. 8,[15][16][17] The HMBC spectrum (Fig. 1) of 2 showed the correlations between the oxymethylene protons (H 2 -1″) and C-7, and between both H-6 and H-8, and C-7, confirming that the prenyloxy group is located at C-7.…”

Section: Chartmentioning

confidence: 88%

“…8,[15][16][17] Thus, the substitution pattern of the A-ring is 5-hydroxy-6-methoxy-7,8-methylenedioxy or 5-hydroxy-6,7-methylenedioxy-8-methoxy. The heteronuclear multiple-bond correlation (HMBC) spectrum (Fig.…”

Section: Chartmentioning

confidence: 99%

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Isolation of Six New Flavonoids from Melicope triphylla

Higa

Imamura

Shimoji

et al. 2012

CHEMICAL & PHARMACEUTICAL BULLETIN

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Six new flavonoids-5-hydroxy-3,8-dimethoxy-3′,4′:6,7-bismethylenedioxyflavone (1), 3,3′,4′,5-tetramethoxy-7-(3-methylbut-2-enyloxy)flavone (2), 7-(2-hydroxy-3-methylbut-3-enyloxy)-3,3′,4′,5-tetramethoxyflavone (3), 7-(2-hydroxy-3-methylbut-3-enyloxy)-3,5-dimethoxy-3′,4′-methylenedioxyflavone (4), 7-(2-hydroxy-3-methyl but-3-enyloxy)-3,3′,4′,5,8-pentamethoxyflavone (5), and 7-(2-hydroxy-3-methylbut-3-enyloxy)-3,5,8-tri methoxy-3′,4′-methylenedioxyflavone (6)-were isolated from the leaves of Melicope triphylla. In addition, six already known flavonoids were also detected: 5-hydroxy-3,6,7-trimethoxy-3′,4′-methylenedioxyflavone (7), 5,7-dihydroxy-3,3′,4′,8-tetramethoxyflavone (8), 4′,5-dihydroxy-3,3′,7,8-tetramethoxyflavone (9), 3,5,6,7,8-penta methoxy-3′,4′-methylenedioxyflavone (10), 3,5,6,7-tetramethoxy-3′,4′-methylenedioxyflavone (11), and 3,3′,4′,5,6,7,8-heptamethoxyflavone (12). The structures of the new compounds were established by spectroscopic methods. Compound 2 displayed ichthyotoxic activity against Japanese killifish (medaka in Japanese) (Oryzias latipes var.) at 10 ppm.

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Section: Resultsmentioning

confidence: 99%

Section: Chartmentioning

confidence: 88%

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Isolation of Six New Flavonoids from Melicope triphylla

Higa

Imamura

Shimoji

et al. 2012

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…[10][11][12][13] Thus, the substitution pattern of the A-ring is 5-hydroxy-7-methoxy. The 13 C-NMR chemical shifts observed for the A-ring of 2 agreed with the 13 C-NMR of 3,3Ј,4Ј,5-tetrahydroxy-7-methoxyflavone (rhamnetin).…”

mentioning

confidence: 99%

“…18) The 13 C-NMR spectrum (Table 2) showed one methoxy carbon at lower magnetic field (61.5 ppm), indicating the presence of two substituents at both positions ortho to the methoxy group. [10][11][12][13] Thus, the substitution pattern of A-ring is 5-hydroxy-6-methoxy-7-isopentenyloxy or 5-hydroxy-7-isopentenyloxy-8-methoxy. Comparison between the 13 C-NMR chemical shifts of the A-ring of 3 and those of 3,4Ј,5-trihydroxy-7-isopentenyloxy-3Ј,8-dimethoxyflavone 19) suggested that the substitution pattern of the A-ring was 5-hydroxy-7-isopentenyloxy-8-methoxy.…”

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confidence: 99%

Isolation of Four New Flavonoids from Melicope triphylla

Higa

Nakadomari

Imamura

et al. 2010

CHEMICAL & PHARMACEUTICAL BULLETIN

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Regular ArticleMelicope triphylla MERR. (Rutaceae) (Awadan in Japanese) is a shrub growing in Southeast Asia. Many flavonoids have been isolated from the leaves [1][2][3][4] and the root and stem bark 1,[5][6][7] of this plant. Some of them have been reported to show piscicidal, 2) antiplatelet aggregating, 3) cytotoxic 4) and vasorelaxing activities.7) In a follow-up investigation, we obtained four new compounds (1-4) and two other known compounds 5 and 6 from the leaves. In this study, we report the isolation and structure elucidation of these new compounds. Results and DiscussionAfter chromatographic separation, the methanol extract of the M. triphylla fresh leaves yielded 5-hydroxy-3,7-dimethoxy-3Ј,4Ј-methylenedioxyflavone (5) 2) and 5-hydroxy-7-isopentenyloxy-3,8-dimethoxy-3Ј,4Ј-methylenedioxyflavone (6), 2) and four new compounds 1-4, in addition to methyl p-geranyloxy-trans-cinnamate and b-amyrin.Compound 1 (yellow needles) showed a positive response to the magnesium-hydrochloric acid test for flavonoids. The IR spectrum of 1 showed peaks at 3300 and 1649 cm Ϫ1 assigned to the hydroxy and a,b-unsaturated carbonyl groups, respectively. The molecular formula of 1 was deduced as C 18 H 14 O 8 by high resolution (HR) electron ionization (EI)-MS (M ϩ m/z 358.0685) (Calcd 358.0687). The UV spectrum of 1 in methanol displayed a band I absorption maximum at a longer wavelength (l max ϭ378 nm), suggesting that compound 1 is a flavonol. Band I showed a bathochromic shift (Dl max ϭ40 nm) upon NaOMe addition, supporting the presence of a 3-hydroxy group. It also exhibited a bathochromic shift (Dl max ϭ63 nm) upon addition of AlCl 3 -HCl mixture, consistent with the presence of a 5-hydroxy group.8) The 1 H-NMR spectrum of compound 1 (Table 1) (1H, dd, Jϭ2.0, 8.3 Hz, H-6Ј)], suggesting that C-3Ј and C-4Ј were substituted in the B-ring. The EI-MS spectrum showed a diagnostic peak at m/z 149 corresponding to the (OCH 2 O)C 6 H 3 -CϵO ϩ fragment (Chart 1), consistent with a 3Ј,4Ј-methylenedioxy substitution pattern for the B-ring.9) The 13 C-NMR spectrum (Table 2) showed that one methoxy carbon resonated at 56.5 ppm suggesting that none or only one of the ortho positions was substituted. It also showed a peak for another methoxy carbon at 61.0 ppm indicating that both positions ortho to the methoxy were substituted. 10-13) Thus, the substitution pattern of A-ring is 5-hydroxy-6,7-dimethoxy or 5-hydroxy-7,8-di- , 3,5-dihydroxy-7,8-dimethoxy-3,4-methylenedioxyflavone (1), 3,5-dihydroxy-7-methoxy-3,4-methylenedioxyflavone (2), 3,5-dihydroxy-7-isopentenyloxy-8-methoxy-3,4-methylenedioxyflavone (3) and 5-hydroxy-3-isopentenyloxy-7-methoxy-3,4-methylenedioxyflavone (4), were isolated from the leaves of Melicope triphylla. In addition, two known flavonoids were detected including 5-hydroxy-3,7-dimethoxy-3,4-methylenedioxyflavone (5) and 5-hydroxy-7-isopentenyloxy-3,8-dimethoxy-3,4-methylenedioxyflavone (6). The structures of the new compounds were established by spectroscopic methods. Isolation of Four New Flavonoids from Me...

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