13C NMR spectral assignment of the A-ring of polyoxygenated flavones

Hòrie, Tokunaru; Ohtsuru, Yoshizumi; Shibata, Kenichi; Yamashita, Kazuyo; Tsukayama, Masao; Kawamura, Yasuhiko

doi:10.1016/s0031-9422(97)00629-8

Cited by 117 publications

(84 citation statements)

References 29 publications

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“…Thus, their structures were identified as Vanillin 14 and salicylic acid. 15 The structural identifications of the compounds 3-7 were based on spectral analysis and also by comparison with literature data, which allowed their assignments as quercetin (3), 16 acacetin (4), 17 7,4′-Di-O-methylisoscutellarein (5), 18 Genkwanin (6), 17 and tiliroside (7). 19 This is the first study reporting the presence of these compounds in Sidastrum micranthum and the first report of the compounds 4, 5, and 6 from the Malvaceae family.…”

Section: Resultsmentioning

confidence: 99%

Phenolic compounds from Sidastrum micranthum (A. St.-Hil.) fryxell and evaluation of acacetin and 7,4'-Di-O-methylisoscutellarein as motulator of bacterial drug resistence

et al. 2011

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Recebido em 13/12/10; aceito em 21/3/11; publicado na web em 5/5/11From the aerial parts of Sidastrum micranthum (A. St.-Hil.) Fryxell (Malvaceae) were isolated m-methoxy-p-hydroxy-benzaldehyde, o-hydroxy-benzoic acid, acacetin, quercetin, 7,4′-Di-O-methylisoscutellarein, genkwanin and tiliroside. These compounds were identified by data analyses of spectroscopic methods. Although acacetin and 7,4′-Di-O-methylisoscutellarein did not display relevant antibacterial activity (MIC = 256 μg/mL), they modulated the activity of antibiotics, i.e. in combination with antibiotics at 64 μg/mL (¼ MIC), a two-fold reduction in the MIC was observed for norfloxacin and ethidium bromide; regarding tetracycline and erythromycin a two-fold reduction in the MIC was observed only with 7,4′-Di-O-methylisoscutellarein.

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Section: Resultsmentioning

confidence: 99%

Phenolic compounds from Sidastrum micranthum (A. St.-Hil.) fryxell and evaluation of acacetin and 7,4'-Di-O-methylisoscutellarein as motulator of bacterial drug resistence

et al. 2011

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“…Although compound 1 has been previously synthesised 8 and isolated from Stachys aegyptiaca 9 but a full 1 H NMR assignment have not been made. In the present study, all 1 H and 13 C shifts were unambiguously and directly assigned by HMQC, HMBC and nOe difference experiments.…”

Section: Resultsmentioning

confidence: 99%

“…This is in agreement with Bolt and Bauch 11 where the methyl groups of -methoxynaphthalene derivatives lie in the plane of the aromatic ring, syn to Cα. However, the methoxy groups at carbons C3, C6, C7 and C8 are not coplanar with ring A, their torsion angles being 110.8 (4) An intramolecular hydrogen bond exists between O3 and O2 [O3 … O2 2.572(4) Å; H3 … O2 1.61(9) Å; O3-H3 1.02(9) Å; O3-H3 … O2 156 (8)]. This is consistent with the absence of nOe enhancement at 11-CH 3 upon irradiation of H3 ( Figure 2).…”

Section: Resultsmentioning

confidence: 99%

Chemical Constituents from Bombacopsis glabra (Pasq.) A. Robyns: Complete ¹H and 13C NMR Assignments and X Ray Structure of 5-Hydroxy-3,6,7,8,4'-pentamethoxyflavone

Paula

Barbosa

Errington

et al. 2002

J. Braz. Chem. Soc.

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Do extrato hexânico da casca do caule de Bombacopsis glabra (Bombacaceae) foram isolados a flavona 5-hidroxi-3,6,7,8,4'-pentametoxiflavona (1) e os triterpenos lupenona, 9,19-ciclolanost-23-eno-3β,25-diol (2), (24R)-9,19-ciclolanost-25-eno-3β,24-diol (3) e (24S)-9,19-ciclolanost-25-eno-3β,24-diol (4). As estruturas foram determinadas por espectroscopia de RMN de 13 C e de 1 H (1D e 2D) e EM, e ainda, por comparação com dados da literatura para os triterpenos. A confirmação inequívoca da estrutura da flavona 1 foi realizada por um estudo de difração de raios X. As cinco substâncias foram isoladas pela primeira vez de espécies de Bombacaceae.The flavone 5-hydroxy-3,6,7,8,4'-pentamethoxyflavone (1) and the triterpenes lupenone, 9,19-cyclolanost-23-ene-3β,25-diol (2), (24R)-9,19-cyclolanost-25-ene-3β,24-diol (3) and (24S)-9,19-cyclolanost-25-ene-3β,24-diol (4) were isolated from the hexane extract of the stem bark of Bombacopsis glabra (Bombacaceae). The structures were determined by 13 C and 1 H NMR (1D and 2D) and mass spectrometry, and by comparison with literature data for triterpenes. The structure of the flavone 1 was unambiguously confirmed by a X-ray diffraction study. The five substances were isolated for the first time from Bombacaceae species.

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“…5,24 Three other known compounds, aglalactone, 3,25 scopoletin, 26 and 5-hydroxy-3,6,7,4′-tetramethoxyflavone 27 were obtained from the leaves and twigs.…”

Section: Resultsmentioning

confidence: 99%

Cytotoxic Flavaglines and Bisamides from Aglaia edulis.

Kim¹,

Chin²,

Su³

et al. 2007

J. Nat. Prod.

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Two new cyclopenta [b]benzofurans, aglaroxin A 1-O-acetate (2) and 3′-methoxyaglaroxin A 1-Oacetate (3), a new benzo [b]oxepine, 19,20-dehydroedulisone A (4), and five new cyclopenta [bc]benzopyrans, edulirin A (5), edulirin A 10-O-acetate (6), 19,20-dehydroedulirin A (7), isoedulirin A (8), and isoedulirin B (9), were isolated from the bark of Aglaia edulis, along with one known cyclopenta [b]benzofuran, aglaroxin A (1). Additionally, four new amides, aglamides A-D (10-13), as well as three known compounds, aglalactone, scopoletin, and 5-hydroxy-3,6,7,4′-tetramethoxyflavone, were isolated from the leaves and/or twigs of this species. The structures of the new compounds (2-13) were elucidated by interpretation of their spectroscopic data. All isolates obtained in this study were evaluated for cytotoxicity against both several human cancer cell lines (Lu1, LNCaP, and MCF-7) and a non-tumorigenic (HUVEC) cell line. Among these isolates, the cyclopenta [b]benzofurans (1-3) exhibited potent in vitro cytotoxic activity (ED 50 range 0.001 to 0.8 μg/mL). Aglaroxin A 1-O-acetate (2) was further evaluated in the in vivo P388 lymphocytic leukemia model, by intraperitoneal injection, but found to be inactive in this model.The cyclopenta [b]benzofurans have been isolated only from the genus Aglaia (Meliaceae) and occur in two structurally related groups of compounds, the benzo [b]oxepines and cyclopenta [bc]benzopyrans. 1,2 These classes of compounds have been termed as "flavaglines" because their mutual biogenetic origin is postulated to involve a flavonoid unit linked to a cinnamic acid moiety. [3][4][5][6] Among the flavaglines, cyclopenta [b]benzofurans have received considerable recent attention as interesting lead compounds for cancer chemotherapy, [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] as a result of the cyclopenta [b]benzofuran derivative, rocaglamide from Aglaia elliptifolia, being found to exhibit antineoplastic activity in an in vivo model. 20 As a part of a National Cooperative Drug Discovery Group (NCDDG) program to discover new antitumor agents from plants, 21, 22 the leaves, twigs, and bark of Aglaia edulis (Roxb.) Wall. (Meliaceae) were separately collected in Indonesia. The chloroform-soluble partitions of the three methanol extracts of these three plant parts were subjected to detailed investigation due to their cytotoxic activities demonstrated against a small panel of human cancer cell lines. 3H, s) in the 1 H NMR spectrum suggested the presence of an acetyl group at C-1. Consistent with the 1 H NMR spectrum of compound 2, its 13 C NMR spectrum also displayed the signals for a disubstituted and a monosubstituted benzene ring, as well as for two quaternary carbons at δ C 101.0 (C-3a) and 93.3 (C-8b). In the HMBC spectrum of compound 2, correlations from H-1 and OAc to the signal at δ C 169.8 indicated the acetoxy group to be located at C-1, while correlations from resonances for H-2 and the two N-Me groups to the signal at δ C 167.5 suggested the location of the amide group at...

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13C NMR spectral assignment of the A-ring of polyoxygenated flavones

Cited by 117 publications

References 29 publications

Phenolic compounds from Sidastrum micranthum (A. St.-Hil.) fryxell and evaluation of acacetin and 7,4'-Di-O-methylisoscutellarein as motulator of bacterial drug resistence

Phenolic compounds from Sidastrum micranthum (A. St.-Hil.) fryxell and evaluation of acacetin and 7,4'-Di-O-methylisoscutellarein as motulator of bacterial drug resistence

Chemical Constituents from Bombacopsis glabra (Pasq.) A. Robyns: Complete ¹H and 13C NMR Assignments and X Ray Structure of 5-Hydroxy-3,6,7,8,4'-pentamethoxyflavone

Cytotoxic Flavaglines and Bisamides from Aglaia edulis.

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