Analysis of kavalactones from Piper methysticum (kava-kava)

Abstract

The chemical analysis and quality control of both Piper methysticum G. Forster (kava-kava) and extracts obtained by aqueous acetone or aqueous methanol as well as supercritical fluid extraction are reviewed. In the last two decades various procedures concerning the separation and detection of kavalactones have been routinely carried out by gas chromatography (without previous derivatization of kavalactones) and high performance liquid chromatography but most of them are not validated or only partially validated. Recently, analyses by supercritical fluid chromatography and micellar electrokinetic chromatography have also been reported. Both gas chromatography and high performance liquid chromatography can be used for the analysis of kavalactones with some advantages and disadvantages for each method. Using gas chromatography analysis, methysticin and yangonin, which are two of the major components, are generally not separated. In addition, the high temperature of the injection port caused the decomposition of methysticin. Concerning high performance liquid chromatography analyses, the reversed-phase is generally better because highly reproducible with a very low detection limit for all compounds even if the quantitative analysis of the kavalactones by liquid chromatography needs to be carried out in the absence of light to prevent the cis/trans isomerisation of yangonin.

Complementary Medicine, Exercise, Meditation, Diet, and Lifestyle Modification for Anxiety Disorders: A Review of Current Evidence

“…A further metaanalysis of six RCTs reported that a standardised Kava extract (WS1490) was effective in significantly improving anxiety relative to placebo (by 5.94 points on the HAM-A) further supporting the anxiolytic effects of Kava [43]. The anxiolytic properties of Kava appear to be due to a collective group of compounds called kavalactones [65]. Amongst numerous mechanisms, kavalactones appear to modulate calcium and sodium channels [66], modify binding of ligands to GABA receptors [67] and inhibit noradrenaline uptake [68].…”

Rapid detection and validated quantification of psychoactive compounds in complex plant matrices by direct analysis in real time‐high resolution mass spectrometry – Application to “Kava” psychoactive pepper products

“…Although a variety of techniques have been applied to qualitative and quantitative studies of kavalactones in Kava products, thermal decomposition, low sensitivity and limitations regarding separation time and peak resolution have proven troublesome in Kava analysis . Near‐infrared reflectance spectroscopy (NIRS) and FTIR with attenuated total reflectance (ATR) have demonstrated advantages including non‐destructiveness, high speed and sensitivity, and involve minimal to no sample preparation for analysis and quantification of major kavalactones .…”

“…However, the poor stability of yangonin in certain solvent systems and calibration curves with low R 2 values for several major kavalactones remain problematic with these methods . A validated SFC method was developed for the quantification of major kavalactones in Kava root powders and extracts, but difficulties in resolving several of the kavalactones were encountered . While multiple HPLC methods for quantification of kavalactones such as normal phase (NP) HPLC, reversed‐phase (RP) HPLC and HPLC/UV have been reported with varied success, long run times, toxic solvents, lengthy sample preparation steps, and difficulties in separating kavalactone peaks due to oily complex matrices, complicate data analysis .…”

“…Their facile thermal decomposition, limitations regarding separation time and peak resolution, and difficulties with complex matrix analysis are typical of the challenges encountered in the detection and quantification of kavalactones. Poor stability in certain solvent systems, calibration curves with low R 2 values, sample degradation, insufficient separation and cis / trans photoisomerization in aqueous and methanolic solvents are complicating factors in the detection and quantification of yangonin using these methods. Therefore, there continues to be a need for the development of suitable approaches for the simultaneous identification of a product as being P. methysticum derived, and for the quantification of its key psychoactive component, yangonin.…”

Oral administration of methysticin improves cognitive deficits in a mouse model of Alzheimer's disease

“…Kavalactones are extracted from the rhizome and roots of kava (Piper methysticum, G. Forst), a plant of the piperaceae family that is common on some Pacific islands [10]. Anthropological evidence suggests that kava has been cultivated and consumed for over 3000 years.…”