Bulbine-Knipholone, a New, Axially Chiral Phenylanthraquinone fromBulbine abyssinica (Asphodelaceae): Isolation, Structural Elucidation, Synthesis, and Antiplasmodial Activity

Bringmann, Gerhard; Menche, Dirk; Brun, Reto; Msuta, Thomas; Abegaz, Berhanu

doi:10.1002/1099-0690(200203)2002:6<1107::aid-ejoc1107>3.0.co;2-4

Cited by 26 publications

(31 citation statements)

References 27 publications

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“…Seven standards were used as reference compounds. One chromone and six anthraquinone type of compounds, 8-C-glycosyl aloesol (1) [18], bulbnatalonoside E (2) [11], bulbnatalonoside D and its atropisomer (3a, b) [11], bulbnatalonoside B (4) [11], knipholone (5) [19], bulbine-knipholone (6) [20], and 6′-methyl knipholone (7) [21] (▶ Fig. 1), were isolated at the National Center for Natural Products Research (NCNPR), University of Mississippi, University, Mississippi, USA.…”

Section: Standards and Chemicalsmentioning

confidence: 99%

Development and Validation of a UHPLC-PDA-MS Method for the Quantitative Analysis of Anthraquinones in Bulbine natalensis Extracts and Dietary Supplements

et al. 2019

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A UHPLC-photodiode array-MS method was developed and validated for the quantification of one chromone and six anthraquinone type of compounds from Bulbine natalensis plant samples and dietary supplements. Metabolites 1 – 7 were identified based on their retention times and electrospray ionization-MS spectra compared with a mix of previously isolated compounds. The quantification of 1 – 7 was based on photodiode array detection. The optimized separation was achieved using a CORTECS C18 column with a gradient of water/acetonitrile as the mobile phase. Seven compounds were separated within 15 minutes with detection limits of 50 pg on the column. The analytical method was validated for linearity, repeatability, accuracy, limits of detection, and limits of quantification. The relative standard deviations for intra- and inter-day experiments were less than 5% and the recovery efficiency was 98 – 101%. Nine dietary supplements labeled as containing B. natalensis were examined. Anthraquinone-type compounds were detected in only five out of nine dietary supplements, with the total amount ranging from 11.3 to 90.4 mg per daily dose. The analytical method is simple, economic, rapid, and can be applied for quality assessment of B. natalensis and dietary supplements. Electrospray ionization-MS was used for the identification of these compounds in plant samples and dietary products.

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Section: Standards and Chemicalsmentioning

confidence: 99%

Development and Validation of a UHPLC-PDA-MS Method for the Quantitative Analysis of Anthraquinones in Bulbine natalensis Extracts and Dietary Supplements

et al. 2019

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“…The phenylanthraquinone, bulbine-knipholone has been isolated from the roots. This compound showed in-vitro antiplasmodial activity and no cytotoxic effects on mammalian cells (Bringmann et al, 2002).…”

Section: Introductionmentioning

confidence: 96%

Mineral Composition and Nutritive Analysis of Bulbine Abyssinica A. Rich. Used in the Treatment of Infections and Complications Associated With Diabetes Mellitus in the Eastern Cape Province, South Africa

Kibiti

Afolayan

2018

Afr J Tradit Complement Altern Med

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Background: B. abyssinica is a succulent member of the genus Bulbine (Asphodelaceae). It occurs from the Eastern Cape, through Swaziland and further north to Ethiopia. The species is used in traditional medicine to treat rheumatism, dysentery, bilharzia, cracked lips and diabetes. The tea leaf is used to treat cough, vaginal and bladder problems. Whereas B. abyssinica has ethno medicinal value, not much data concerning its phytonutrient, macro and micro element composition can be found in literature. Materials and Methods: Therefore, the present study was undertaken to determine the nutritional quantitative composition of the plant using standard procedures. Results: The proximate analysis revealed the carbohydrate, crude fibre, moisture, ash, crude protein and crude fat contents as 74.8%, 8.9%, 8.8%, 8%, 7.7% and 0.6%, respectively. The species showed high levels of oxalates and phytic acids, moderate levels of alkaloids, flavonoids, saponins and phenols, while tannins were in low levels. Vitamin A, C and E contents were 12, 12.3 and 22.1 mg/100g, respectively. Amongst the mineral elements investigated, potassium and calcium were in high levels. Magnesium, iron, sodium, aluminium and phosphorus were moderately present, while manganese, zinc and copper where in low amounts. These vitamins and mineral elements were within their recommended daily allowance in humans. Conclusion: The amount of these phytochemicals suggests the plant can serve as nutritional supplements which are vital in maintaining good health status. These findings also suggest the potential role of B. abyssinica in the treatment of infections and some chronic diseases, especially diabetes mellitus.

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“…Among the novel-type structures thus discovered recently by our group, are, i.a., unique acetogenic alkaloids (Bringmann and Pokorny 1995;Bringmann et al 1998aBringmann et al , 2005Bringmann et al , 2006a but also nitrogen-free compounds like, e.g., mono- (Abegaz et al 2002;Bringmann et al 2002a) and dimeric (Bringmann et al 2007c) phenylanthraquinones, with knipholone (1) (Fig. 1) as the longest-known representative (Dagne and Steglich 1984).…”

Section: Introductionmentioning

confidence: 99%

“…• Furthermore, phenylanthraquinones are interesting pharmacologically, exhibiting antiplasmodial (Bringmann et al 1999;Bringmann et al 2002a;Wube et al 2005) and antitumoral (QhotsokoaneLusunzi and Karuso 2001a;Bringmann et al 2007c) activities, different for the two respective rotational isomers (Kuroda et al 2003), showing that the phenomenon of atropisomerism is of concrete relevance and not just an academic issue. • And, in particular, these compounds are formed via a most remarkable biosynthetic pathway!…”

Section: Introductionmentioning

confidence: 99%

Acetogenic anthraquinones: biosynthetic convergence and chemical evidence of enzymatic cooperation in nature

Bringmann¹,

Irmer²

2008

Phytochem Rev

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Phenylanthraquinones belong to the quite rare class of fully unsymmetric biaryls, consisting of two different molecular portions, an anthraquinone part, chrysophanol, and a phenyl part, 2,4-dihydroxy-6-methoxyacetophenone, linked together by phenol-oxidative coupling. The biosynthesis of these two moieties, from eight and four acetate units, respectively, bears some unique features: Chrysophanol is the first example of an acetogenic natural product that is, in an organismspecific manner, formed via more than one folding mode: In eukaryotes, like, e.g., in fungi, in higher plants, and in insects, it is formed via folding mode F, while in prokaryotes it originates through mode S. It has, more recently, even been found to be synthesized by a third pathway, which we have named mode S 0 . It is thus the first example of biosynthetic convergence in polyketide biosynthesis. The monocyclic ''southern'' portion of the molecule, which is much simpler (arising from only four acetate units and without decarboxylation), unexpectedly does not show the anticipated randomization of the C 2 -labeling in the aromatic ring, but has clearly localized C 2 units, excluding any symmetric intermediate like, e.g., 2,4,6-trihydroxyacetophenone. This is confirmed by competitive feeding experiments with specifically 13 C 2 -labeled acetophenones, showing the O-methylation to be the decisive symmetry-preventing step, which hints at a close collaboration of the participating enzymes. The results make knipholone an instructive example of structure, function, and evolution of polyketide synthases and O-methyltransferases, and their cooperation.

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Bulbine-Knipholone, a New, Axially Chiral Phenylanthraquinone fromBulbine abyssinica (Asphodelaceae): Isolation, Structural Elucidation, Synthesis, and Antiplasmodial Activity

Cited by 26 publications

References 27 publications

Development and Validation of a UHPLC-PDA-MS Method for the Quantitative Analysis of Anthraquinones in Bulbine natalensis Extracts and Dietary Supplements

Development and Validation of a UHPLC-PDA-MS Method for the Quantitative Analysis of Anthraquinones in Bulbine natalensis Extracts and Dietary Supplements

Mineral Composition and Nutritive Analysis of Bulbine Abyssinica A. Rich. Used in the Treatment of Infections and Complications Associated With Diabetes Mellitus in the Eastern Cape Province, South Africa

Acetogenic anthraquinones: biosynthetic convergence and chemical evidence of enzymatic cooperation in nature

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