Xanthones

Hostettmann, Kurt; Hostettmann, M.

doi:10.1016/b978-0-12-461011-8.50020-2

Cited by 56 publications

(40 citation statements)

References 79 publications

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“…Each of these compounds present MS and NMR signals consistent with the presence of a prenyl group. Compound 2 ([M + ] at m/z 328) exhibited a pair of ortho-coupled at l 6.95 and 7.61; these high values can only be due to protons located in the deshielded area of the carbonyl group [6] and this, together with the data from UV, confirmed the proposed oxygenation pattern. The prenyl group was located at C2 and not at C4, by comparison of the H4 l value with those obtained for compound 7 and 10.…”

Section: Identified Xanthonessupporting

confidence: 69%

“…Elution was carried out as described before [15]. Identification of the isolated xanthones was carried out by mass spectrometry (EI-MS probe 70 eV), and by 1 H-NMR (300 MHz, acetone-d 6 , ppm/TMS) and 13 C-NMR (70.5 MHz, acetone-d 6 , ppm/TMS) spectrometry, as well as by UV spectroscopy study with the classical reagents [7,16].…”

Section: Isolation and Identification Of Xanthonesmentioning

confidence: 99%

“…This type of compound is widely found in the Hypericaceae family and has interesting pharmacological properties. Xanthones exhibit strong and selective inhibition of monoamine oxidase A, in vitro cytotoxicity and in vivo antitumor activity, as well as antibacterial and antifungic activities ( [6,7], and refs. therein).…”

Section: Introductionmentioning

confidence: 99%

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Xanthone biosynthesis and accumulation in calli and suspended cells of Hypericum androsaemum

et al. 2000

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Calli and suspended cells of Hypericum androsaemum accumulated high levels of 1,3,5,6 and 1,3,6,7 oxygenated xanthones. The major compounds include simple oxygenated xanthones or derivatives with prenyl, pyran or methoxyl groups, four of them being new natural compounds. A hypothetical biosynthetic scheme is proposed based on the isolated compounds and statistical analysis. Xanthone accumulation was influenced greatly by medium factors, namely hormone supplementation. Calli grown with 4.5 mM a-naphtaleneacetic acid (NAA) +2.3 mM kinetin (KIN) had the highest specific xanthone production (1.3% biomass dry weight (DW)), whereas suspended cells grown in similar medium accumulated a lower amount (0.87% DW). Calli displayed a negative linear relationship between total xanthone accumulation and NAA concentration, in the range of 4.5 -22.5 mM. However, in this range the xanthone 1,3,6,7/1,3,5,6 ratio and the biomass production showed a positive linear relationship with NAA concentration. Substitution of 4.5 mM of NAA by the same molar amount of 2,4-dichlorophenoxyacetic acid (2,4-D), in the presence of 2.3 mM of KIN, caused a decrease in xanthone accumulation in calli. The use of N 6 -benzyladenine (BA) instead of KIN reduced xanthone production, independently of the auxin used. This effect was attenuated when both hormones were present.

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Section: Identified Xanthonessupporting

confidence: 69%

Section: Isolation and Identification Of Xanthonesmentioning

confidence: 99%

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Xanthone biosynthesis and accumulation in calli and suspended cells of Hypericum androsaemum

et al. 2000

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“…Xanthones form a large group of natural products widely found only in some higher plant families, lichens and fungi (Sultanbawa, 1980;Hostettmann & Hostettmann, 1989). In a recent review, Vieira and Kijjoa (2005) showed that, in only five years, 515 different xanthones were reported in the plant kingdom, 278 of them being new natural xanthones.…”

Section: A Mangiferin and Isomangiferin Determinationmentioning

confidence: 99%

First report on mangiferin (C-glucosyl-xanthone) isolated from leaves of a wild coffee plant,Coffea pseudozanguebariae(Rubiaceae)

Talamond

Mondolot²,

Gargadennec³

et al. 2008

Acta Botanica Gallica

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Abstract.-Bean biochemical composition has been extensively analyzed inCoffea species because of its impact on coffee beverage quality. C. pseudozanguebariae appeared as an interesting wild species because of its low caffeine and chlorogenic acid content, compounds involved in coffee bitterness. Extending the study to its leaves revealed the presence of two unknown phenolic compounds. Isolation, then identification by MS and NMR analysis proved that these compounds are two C-glucosyl-xanthones: mangiferin and isomangiferin. HPLC analyses indicated very high mangiferin content in young leaves. This class of compounds is described for the first time not only in coffee plants but also in the Rubiaceae family. The interest of mangiferin identification in the Coffea genus is discussed.Key words : C-glucosyl-xanthones -Coffea pseudozanguebariae -leavesmangiferin -Rubiaceae.Résumé.-La composition biochimique des grains de café a été très étudiée en raison de son impact sur la qualité de la boisson. Coffea pseudozanguebariae apparaît comme une espèce sauvage intéressante en raison de sa faible teneur en caféine et en acide chlorogénique, composés participant à l'amertume du café. L'analyse étendue aux feuilles de cette espèce a révélé la présence de deux composés inconnus. Leur isolement puis leur détermination par SM et RMN prouvent qu'il s'agit de deux C-glucosyl-xanthones : la mangiférine et l'isomangiférine. Les dosages par CLHP ont montré une teneur particulièrement éle-vée en mangiférine dans les jeunes feuilles. C'est la première fois que cette classe de composés est décrite, non seulement chez un caféier mais aussi dans la famille des Rubiaceae. L'intérêt de l'identification de la mangiférine dans le genre Coffea est discuté.

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“…Xanthones are formed in at least 30 families of higher plants (e.g. Gentianaceae and Guttiferae) [4,5]. 1,3,5,8-Tetrahydroxyxanthone (13, Fig.…”

mentioning

confidence: 99%

Phenylalanine‐independent biosynthesis of 1,3,5,8‐tetrahydroxyxanthone

Wang¹,

Maier²,

Keil

et al. 2003

European Journal of Biochemistry

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Root cultures of Swertia chirata (Gentianaceae) were grown with supplements of [1‐13C]glucose, [U‐13C6]glucose or [carboxy‐13C]shikimic acid. 1,3,5,8‐Tetrahydroxyxanthone was isolated and analysed by quantitative NMR analysis. The observed isotopomer distribution shows that 1,3,5,8‐tetrahydroxyxanthone is biosynthesized via a polyketide‐type pathway. The starter unit, 3‐hydroxybenzoyl‐CoA, is obtained from an early shikimate pathway intermediate. Phenylalanine, cinnamic acid and benzoic acid were ruled out as intermediates.

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Xanthones

Cited by 56 publications

References 79 publications

Xanthone biosynthesis and accumulation in calli and suspended cells of Hypericum androsaemum

Xanthone biosynthesis and accumulation in calli and suspended cells of Hypericum androsaemum

First report on mangiferin (C-glucosyl-xanthone) isolated from leaves of a wild coffee plant,Coffea pseudozanguebariae(Rubiaceae)

Phenylalanine‐independent biosynthesis of 1,3,5,8‐tetrahydroxyxanthone

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