Simultaneous quantitation of kavalactones in kava dry extracts: comparison of multi‐standards and single standard validation approaches

Abstract

Introduction Dried extracts of Piper methysticum G. Forst, also known as kava, has been widely used due to its anxiolytic and sedative properties. In order to assure the quality of these extracts, it is essential to accurately quantify kavalactones, known as the active principle. Objectives To develop and validate an analytical method for the simultaneous quantification of six major kavalactones (kavain, dihydrokavain, methysticin, dihydromethysticin, yangonin and demethoxyyangonin) in kava extracts, comparing multi‐standards and single standard validation approaches. Material and methods Separation was performed using a C18 column, water/methanol/acetonitrile/2‐propanol (66:07:09:18 v/v/v/v) and detection at 245 and 350 nm. A full method validation was performed, employing analytical standards for each compound. Commercial kava dried extracts were assayed and the results obtained using the method validated for six kavalactone standards were compared with those obtained when only kavain was used as standard. Results Baseline resolution for all kavalactones was obtained in short run time (15 min). Although the total kavalactone content varied between samples, a similar distribution profile was observed. When the method validated with all six analytical standards was compared to the calibration using only kavain standard, kavalactone contents were considerably different (from 7.57 to 36.53%). Conclusion The obtained results demonstrate the importance of a validated method using individual kavalactone standards for the effective quality control of kava extracts. In a next step, the method needs to be adapted to also include flavokavin B (FKB), as an important authentication marker to distinguish between the accepted variety “noble Kava” and the toxic “two‐day Kava”.

Evaluation of the Effects of Extracts Containing Valeriana officinalis and Piper methysticum on the Activities of Cytochrome P450 3A and P-Glycoprotein

“…The content of KVN in the kava-kava capsules was 2.1 ± 0.1% (w/w), equivalent to 13.7 ± 0.3 mg/capsule. This value is in agreement with a previous study that found values between 1.2 to 5.2% (w/w) 25 . The quality control analysis of the P. methysticum capsules demonstrated the presence of other peaks in addition to KVN ( 3 ) ( Fig.…”

“…The content of KVN (the main chemical active constituent) was determined by HPLC as already described by our group [25]. Briefly, a stock solution of the KVN standard (1 mg/mL) was prepared in methanol.…”

Quantitative and rapid quality assessment methods for the multi‐class bioactive constituents of Tinospora cordifolia using high‐performance liquid and thin layer chromatography analysis with tandem mass spectrometry characterization

“…In addition, these TC compounds were calculated using tinosporide as a single standard in the validated analytical method [32]. Supporting Information Table S4 showed that the content values (% relative error) differed from results obtained against external standard standards from 25.00% to 70.34% (Table S5) for 15 samples in a single standard approach due to contributing factors of variations in chemical classes and polarity of compounds.…”

“…Further, each sample was analyzed in triplicate using an external standard, single standard (tinosporide), and optimized multi-class standards (cordifolioside A, magnoflorine, 20-β-hydroxy ecdysone, tinosporide) approach with the respective % coefficient of variations. The multi-class standards were selected per the representative chemical class of TC compounds [32]. These optimized four multi-class standards were selected from clerodane diterpene glycosides (cordifolioside A, syringin, tinosporaside), alkaloids (magnoflorine, jatrorrhizine, tetrahydropalmatine), clerodane furanoditerpenes (8-hydroxy tinosporide, tinosporide, columbin), and phytosterol class (20-β-hydroxy ecdysone).…”

An Updated Review on the Psychoactive, Toxic and Anticancer Properties of Kava

“…Ultra-performance liquid chromatography high-resolution tandem mass spectrometry (UPLC–MS/MS) has also shown high selectivity and specificity, which can be useful to characterize kava products and to obtain more information on its pharmacokinetics data in animals and humans [ 33 ]. Finally, the usage of high-performance liquid chromatography interfaced to a diode array detector (HPLC–DAD) allowed the quantification of total kavalactone content and its distribution profile [ 34 ].…”