<sup>13</sup>C nuclear magnetic resonance spectral and conformational analysis of naturally occurring tetrahydrofuran lignans

Fonseca, S.F.; Barata, Lauro Euclides Soares; Rúveda, Edmundo A.; Baker, Paul

doi:10.1139/v79-071

Cited by 31 publications

(16 citation statements)

References 6 publications

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“…17,23) These chemical shifts are characteristic of a tetrahydrofuran ring with a cis-configuration of one aryl and methyl substituent as well as a trans-configuration of the other aryl and methyl group, whereas the two methyl groups are trans-oriented to each other. 24,25) Due to the asymmetric stereochemistry of the tetrahydrofuran substituents it had to be determined which of the two aryl substituents showed a cis orientation to the neighboring methyl group. This was deduced from the correlations of HMBC and NOESY spectra (Fig.…”

Section: Resultsmentioning

confidence: 99%

Neolignans from Piper futokadsura and Their Inhibition of Nitric Oxide Production

Konishi

Konoshima

Daikonya

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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From a MeOH extract of the aerial part of Piper futokadsura, the tetrahydrofuran lignans, futokadsurin A [(7S,8S,7'S,8'R)-3,4,3'-trimethoxy-4'-hydroxy-7,7'-epoxylignan], futokadsurin B [(7R,8R,7'R,8'S)-3,4-dimethoxy-3',4'-methylenedioxy-7,7'-epoxylignan], and futokadsurin C [(7R,8R,7'S,8'S)-3,4-methylenedioxy-3',4'-dimethoxy-7,7'-epoxylignan] were isolated, together with nine known neolignans. In addition, L-tryptophan, pellitorine, phytol, elemicin, and 1,2,4-trimethoxyphenyl-5-aldehyde were isolated. The structures of the new compounds were elucidated using spectroscopic methods. These lignans inhibited nitric oxide production by a murine macrophage-like cell line (RAW 264.7), which was activated by lipopolysaccharide and interferon-gamma.

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Section: Resultsmentioning

confidence: 99%

Neolignans from Piper futokadsura and Their Inhibition of Nitric Oxide Production

Konishi

Konoshima

Daikonya

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…9 In most instances only relative configurations have been determined and further studies have relied on spectroscopic and correlation data to assign absolute configurations. [3][4][5][6][7]10 Efforts in enantioselective synthesis of these lignans have been sparse. 11 Often, racemic (or meso) mixtures resulting from oxidative coupling of diaryl 1,4-ketones have been obtained, 12 and separated by chiral HPLC.…”

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confidence: 99%

Total Synthesis and Stereochemical Confirmation of 2,5-Diaryl-3,4-dimethyltetrahydrofuran Lignans: (+)-Fragransin A₂, (+)-Galbelgin, (+)-Talaumidin, (-)-Saucernetin and (-)-Verrucosin

Hanessian¹,

Reddy²

2007

Synlett

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“…[224,226] Four natural stereoisomers of tetrahydrofuran lignans (structures II to V) have been reported so far from plants (Figure 105). [227] Since the experimental analysis data were in agreement with the literature data, form IV was proposed as the relative configuration of the isolated ganschisandrine (122).…”

Section: Ganschisandrinesupporting

confidence: 72%

Bandamycin as New Antifungal Agent and further Secondary Metabolites from Terrestrial and Marine Microorganisms

Bahi¹

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Despite successes in controlling some previously thought incurable diseases, recent increase in epidemic viral infections such as AIDS, hepatitis, Ebola, SARS have been reported in developing countries (Asia, Africa). [9] Therefore, the intention to search for new resources of bioactive metabolites still gains worldwide attention, as 11 Pimaricin (12) belongs to the group of polyene macrolide with 26-membered ring possessing antifungal activity. [28] The pimaricin analogue JBIR-13 (13) isolated from Streptomyces bicolor NBRC 12746 has been reported to show antifungal activity against Candida albicans with a minimum inhibitory concentration (MIC) value of 3.13 g/mL. [29] 17 Ionophore antibiotics are another type of antibiotics of bacterial origin, which can act as mobile ion carriers in complex form within cell membranes. [34] Nonactin (18) is an example with antitumor activity: it was firstly isolated and reported from Streptomyces griseus; in addition to (-)-nonactic acid (19), the monomer of nonactin (18). [35,36] 23 Six new chromophenazines A (24), B (26), C (25), D ( 27), E (28) and F (29) were isolated recently in our group from the terrestrial Streptomyces sp. Ank 315.Phenazine derivatives have been reported to exhibit broad-range activities such as antioxidant, neuroprotectant, antimicrobial, antiviral, antiparacitic, antitumor and antimalaria. Among the six chromophenazines, only chromophenazine D ( 27) 36Val-geninthiocin (37) is another thiopeptide antibiotic, which was recently isolated in our group from the terrestrial Streptomyces sp. RSF18. [49] This type of antibiotics is also strongly active as antimalarial agent against Plasmodium falciparum. [50] 2010. [65] Enniatin B (49) and bassianolide ( 50) are examples of fungi-originated cyclodepsipeptides. Enniatins act as ionophores in biological membranes, inhibitors of the ABC-transporter Pdr5p and topical agent for the treatment of respiratory infec-O 68 Recently, four new 10-membered lactones A (69), B (70), C (71) and D (72)have been reported from marine-derived endophytic fungus Curvularia sp. The fungus was isolated from the marine red alga Acanthophora spicifera. [76]

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¹³C nuclear magnetic resonance spectral and conformational analysis of naturally occurring tetrahydrofuran lignans

Cited by 31 publications

References 6 publications

Neolignans from Piper futokadsura and Their Inhibition of Nitric Oxide Production

Neolignans from Piper futokadsura and Their Inhibition of Nitric Oxide Production

Total Synthesis and Stereochemical Confirmation of 2,5-Diaryl-3,4-dimethyltetrahydrofuran Lignans: (+)-Fragransin A₂, (+)-Galbelgin, (+)-Talaumidin, (-)-Saucernetin and (-)-Verrucosin

Bandamycin as New Antifungal Agent and further Secondary Metabolites from Terrestrial and Marine Microorganisms

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13C nuclear magnetic resonance spectral and conformational analysis of naturally occurring tetrahydrofuran lignans

Cited by 31 publications

References 6 publications

Neolignans from Piper futokadsura and Their Inhibition of Nitric Oxide Production

Neolignans from Piper futokadsura and Their Inhibition of Nitric Oxide Production

Total Synthesis and Stereochemical Confirmation of 2,5-Diaryl-3,4-dimethyltetrahydrofuran Lignans: (+)-Fragransin A2, (+)-Galbelgin, (+)-Talaumidin, (-)-Saucernetin and (-)-Verrucosin

Bandamycin as New Antifungal Agent and further Secondary Metabolites from Terrestrial and Marine Microorganisms

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¹³C nuclear magnetic resonance spectral and conformational analysis of naturally occurring tetrahydrofuran lignans

Total Synthesis and Stereochemical Confirmation of 2,5-Diaryl-3,4-dimethyltetrahydrofuran Lignans: (+)-Fragransin A₂, (+)-Galbelgin, (+)-Talaumidin, (-)-Saucernetin and (-)-Verrucosin