Mass spectral characterization of urinary metabolites of d,l-kawain

Köppel, Claus; Tenczer, J.

doi:10.1016/0378-4347(91)80578-z

Cited by 23 publications

(22 citation statements)

References 8 publications

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“…The given data (Table I) about the consumers' behaviour was based on the consumers self-reporting. Kavain, 7,8-dihydrokavain, methysticin and yangonin are known to be stable in methanol [10][11][12]. Therefore, the methanolic extraction of the hair matrix and subsequent fluid-fluid extraction were suitable.…”

Section: Resultsmentioning

confidence: 99%

“…Nowadays, for instance in New Caledonian and Fijian kava bars, kava is prepared by crushing the dry roots of Piper methysticum in tap water, in a basin, then filtered and drunk. Several studies about the detection and identification of kavalactones and their metabolites in urine have been published [9][10][11][12]. Kavain and its main metabolites have also been detected in blood [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

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Chromatographic hair analysis for natural kavalactones and their metabolites. A preliminary study

Tarbah¹,

Barguil

Müller

et al. 2013

Ann Toxicol Anal

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-Purpose: Kava is a traditional Pacific beverage made from the root of Piper methysticum. It is mainly used for its sedative properties due to lipophilic lactones called kavalactones. Kava action mechanisms include cell membrane stabilisation, inhibition of intracellular Ca 2+ increase and enzyme inactivation. Chronic or heavy consumption of kava is responsible for the skin taking on a scaly aspect. Biologically, an isolated increase in serum gamma-glutamyltransferase is noted. "Kava bars" or "nakamals" are numerous in the Pacific. In northern Australia, the use of kava is regulated in order to fight against the abuse of this drink. In metropolitan France, we note the presence of some kava bars in several cities. In New Caledonia, in ten years (December 2002-May 2013, we identified twenty-six cases where kavalactones were found in the blood of perpetrators or victims of fatal accidents (resulting in nineteen deaths and twenty-one people seriously injured), suicides and attacks. In addition, in nine cases of sudden unexplained deaths, significant concentrations of kavalactones were found in the blood of the victims. These figures, however, are understated as toxicological screening was not done systematically. As all toxicological laboratories are not identically equipped, we developed three simple and sensitive methods for the determination of kavalactones in human hair using HPLC-DAD, LC-MS/MS and GC/TOF-MS. Methods: Hair samples were collected from nine people of different origins (Caucasian, Melanesian, Indonesian and African). Kava consumption varied among these people (from a single oral dose of a medication sold on the internet, to a daily intake of several units of the kava beverage). Results: Using HPLC-DAD, the concentrations of kavalactones in human hair samples ranged between 0.2 and 25 ng/mg for kavain, 0.5 and 34 ng/mg for 7,8-dihydrokavain, 0.7 and 8 ng/mg for yangonin, 1 and 14 ng/mg for 5,6-dehydrokavain (=desmethyoxyyango-nin) and 0.9 and 6 ng/mg for the metabolite 12-hydroxy-5,6-dehydrokavain. Methysticin, 7,8-dihydromethysticin and the metabolite 11-hydroxy-5,6-dehydrokavain were detected but not quantified. Additionally, 12-hydroxykavain and 12-hydroxy-7,8-dihydrokavain were detected by LC-MS/MS in one case. General screening for other drugs as well as confirmation of the HPLC-DAD results was performed by GC/TOF-MS. Conclusions: The results of this pilot study indicate that kavalactones (kavain, 7,8-dihydrokavain, methysticin, 7,8-dihydromethysticin, 5,6-dehydrokavain (=desmethyoxyyangonin) and yangonin) accumulate in the keratin matrix of hair and can provide an easily applicable system for assessing chronic consumption of kava. This preliminary study must continue on a larger number of subjects using GC/TOF-MS and LC-MS/MS in order to conduct a comparative analysis among the three methods. Internet, à l'absorption quotidienne de plusieurs unités de boisson kava). Résultats : Déterminées par HPLC-DAD, les concentrations de kavalactones dans des échantillons de cheveux variaient de...

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Chromatographic hair analysis for natural kavalactones and their metabolites. A preliminary study

Tarbah¹,

Barguil

Müller

et al. 2013

Ann Toxicol Anal

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“…Six major kavapyrones (a-pyrones), pharmacologically active substances from the roots of Piper methysticum Forst., are used for standardization of these herbal medicines. Apart from two major achiral kavapyrones, yangonin (5) and desmethoxyyangonin (6), the remaining four major kavapyrones, kavain (2), dihydrokavain (1), methysticin (4), and dihydromethysticin (3), are chiral components ( Table 1). Due to their occurrence as (+)-enantiomers in Piper methysticum Forst., enantioselective analysis of these compounds is useful in authenticity checks on natural plant extracts, as demonstrated by Hä berlein et al using a HPLC method with a ChiraSpher NT column as chiral selector [2,3].…”

Section: Introductionmentioning

confidence: 99%

“…Due to their occurrence as (+)-enantiomers in Piper methysticum Forst., enantioselective analysis of these compounds is useful in authenticity checks on natural plant extracts, as demonstrated by Hä berlein et al using a HPLC method with a ChiraSpher NT column as chiral selector [2,3]. Apart from this, stereodifferentiation may be useful in pharmacological activity and metabolism studies of single kavapyrone enantiomers [4]. In gas chromatography modified cyclodextrins, pure or diluted in polysiloxanes, play an important role as chiral stationary phases [5,6].…”

Section: Introductionmentioning

confidence: 99%

Enantioselective analysis of kavapyrones by high resolution gas chromatography

Beck

Mosandl

2001

J. Sep. Science

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“…Based upon a study by Köppel and Tenczer (1991), the JECFA concluded that hydrolysis of the alpha,beta-unsaturated delta-lactones to the corresponding ring-opened hydroxycarboxylic acids may occur, but that there is no information available to predict that this is the major route of metabolism. However, Köppel and Tenczer (1991) analysed the metabolism of D,Lkawain ((2R)-4-methoxy-2-[(E)-2-phenylethenyl]-2,3-dihydropyran-6-one). Due to the aromatic ring and the hydroxyl-group the Panel considered that this substance is not sufficiently structurally related to the candidate substances 10.037 and 10.044].…”

Section: Efsa Considerationsmentioning

confidence: 99%

Scientific Opinion on Flavouring Group Evaluation 98 (FGE.98): Consideration of three ring‐unsaturated delta‐lactones

Flavourings¹

2011

EFS2

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ABSTRACTth meeting in 1997. The JECFA considered that further information on the metabolism of these three substances was required and that they should be evaluated together with other substances containing alpha,beta-unsaturation and that, therefore, their evaluation should be deferred. However, the EFSA Panel has considered that these three JECFA evaluated aliphatic lactones can be hydrolysed and metabolised to innocuous products in line with the aliphatic lactones evaluated by EFSA in FGE.10Rev2. The substances were evaluated through a stepwise approach that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity. The Panel concluded that all three substances do not give rise to safety concern at their levels of dietary intake, estimated on the basis of the MSDI approach.

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Mass spectral characterization of urinary metabolites of d,l-kawain

Cited by 23 publications

References 8 publications

Chromatographic hair analysis for natural kavalactones and their metabolites. A preliminary study

Chromatographic hair analysis for natural kavalactones and their metabolites. A preliminary study

Enantioselective analysis of kavapyrones by high resolution gas chromatography

Scientific Opinion on Flavouring Group Evaluation 98 (FGE.98): Consideration of three ring‐unsaturated delta‐lactones

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