Efficacy of extracting solvents to chemical components of kava (Piper methysticum) roots

  • Tran Dang Xuan
  • Masakazu Fukuta
  • Ao Chang Wei
  • Abdelnaser Abdelghany Elzaawely
  • Tran Dang Khanh
  • Shinkichi Tawata


The chemical composition of kava (Piper methysticum) lactones and various phytochemicals obtained following the sonication of ground kava roots extracted in the solvents hexane, chloroform, acetone, ethanol, methanol and water, respectively, was analyzed. Eighteen kava lactones, cinnamic acid bornyl ester and 5,7-dimethoxy-flavanone, known to be present in kava roots, were identified, and seven compounds, including 2,5,8-trimethyl-1-naphthol, 5-methyl-1-phenylhexen-3-yn-5-ol, 8,11-octadecadienoic acid-methyl ester, 5,7-(OH)2-4′-one-6,8-dimethylflavanone, pinostrobin chalcone and 7-dimethoxyflavanone-5-hydroxy-4′, were identified for the first time. Glutathione (26.3 mg/g) was found in the water extract. Dihydro-5,6-dehydrokavain (DDK) was present at a higher level than methysticin and desmethoxyyagonin, indicating that DDK is also a major constituent of kava roots. Acetone was the most effective solvent in terms of maximum yield and types of kava lactones isolated, followed by water and chloroform, whereas hexane, methanol, and ethanol were less effective as solvents. Total phenolic and antioxidant activity varied among the extracting solvents, with acetone and chloroform producing the highest effects, followed by water, while methanol, ethanol and hexane were less effective.


Antioxidant Extracting solvent Kava lactone Kava root Piper methysticum Total phenolics 



The authors express sincere thanks to the Grand-in-Aid for Scientific Research (No. 18880020) by Japan Society for the Promotion of Science (JSPS) to Dr. Tran Dang Xuan.


  1. 1.
    Bilia AR, Gallori S, Vincieri FF (2002) Kava–kava and anxiety: growing knowledge about the efficacy and safety. Life Sci 70:2581–2597PubMedCrossRefGoogle Scholar
  2. 2.
    Singh YN (1992) Kava: an overview. J Ethnopharm 37:13–45CrossRefGoogle Scholar
  3. 3.
    Singh YN, Blumenthal M (1997) Kava, an overview. HerbalGram 39:34–55Google Scholar
  4. 4.
    Chevallier A (1996) The encyclopedia of medicinal plants. DK Publ, New YorkGoogle Scholar
  5. 5.
    Leung AY, Foster S (1996) Encyclopedia of common natural ingredients. Wiley, New YorkGoogle Scholar
  6. 6.
    Mors WB, Magalhaes MT, Gottlieb OR (1962) Naturally occurring aromatic derivatives of monocyclic α-pyrones. In: Par R (ed) Progress in the chemistry of organic natural products, vol 20. Vienna New York Springer, pp 131–161Google Scholar
  7. 7.
    Sahelian R (1998) Clinical uses of kava. In kava, the miracle antianxiety herb. St Martin’s Press, New York, pp 85–88Google Scholar
  8. 8.
    Bilia AR, Bergonzi MC, Lazari D, Vinceiri FF (2002) Characterization of commercial kava–kava herbal drug and herbal drug preparations by means of nuclear magnetic resonance spectroscopy. J Agric Food Chem 50:5016–5025PubMedCrossRefGoogle Scholar
  9. 9.
    Whitton PA, Lau A, Salisbury A, Whitehouse J, Evans CS (2003) Kava lactones and the kava–kava controversy. Phytochemistry 64:673–679PubMedCrossRefGoogle Scholar
  10. 10.
    Stickel F, Baumuller HM, Seitz K, Vasilakis D, Seitz G, Seitz HK, Schuppan D (2002) Hepatitis induced by kava (Piper methysticum rhizoma). J Hetatol 39:62–67Google Scholar
  11. 11.
    Zou L, Henderson GL, Harkey MR, Sakai Y, Li A (2004) Effects of kava (kava–kava, ‘Awa', Yaqona, Piper methysticum) on c-DNA-expressed cytochrome P450 enzymes and human cryopreserved hepatocytes. Phytomedicine 11:285–294Google Scholar
  12. 12.
    Clouatre DL (2004) Kava kava: examining new reports of toxicity. Toxicol Lett 150:85–96PubMedCrossRefGoogle Scholar
  13. 13.
    Meissner O, Haberlein H (2005) HPLC analysis of flavokavins and kavapyrones from Piper methysticum Forst. J Chromatogr B 826:46–49CrossRefGoogle Scholar
  14. 14.
    Xuan TD, Elzaawely AA, Fukuta M, Tawata S (2006) Herbicidal and fungicidal activities of lactones in kava (Piper methysticum). J Agric Food Chem 54:720–725PubMedCrossRefGoogle Scholar
  15. 15.
    Wu D, Nair MG, Dewitt DL (2002) Novel compounds from Piper methysticum Forst (kava kava) roots and their effect on cyclooxygenase enzyme. J Agric Food Chem 50:701–705PubMedCrossRefGoogle Scholar
  16. 16.
    Dragull K, Yoshida WY, Tang CS (2003) Piperidine alkaloids from Piper methysticum. Phytochemistry 63:193–198PubMedCrossRefGoogle Scholar
  17. 17.
    Tawata S, Taira S, Kobamoto N, Ishihara M, Toyama S (1996) Syntheses and biological activities of dihydro-5,6-dehydrokawain derivatives. Biosci Biotech Biochem 60:1643–1645CrossRefGoogle Scholar
  18. 18.
    Kähkönen MP, Hopia AI, Vuorela HJ, Rauha J, Pihlaja K, Kujala TS, Heinonen M (1999) Antioxidant activity of plant extract containing phenolic compounds. J Agric Food Chem 47:3954–3962PubMedCrossRefGoogle Scholar
  19. 19.
    Abe N, Murata T, Hirota A (1998) Novel DPPH radical scavengers, bisorbicillinol and demethltrichdimerol, from a fungus. Biosci Biotech Biochem 62:661–666CrossRefGoogle Scholar
  20. 20.
    Son S, Lewis BA (2002) Free radical scavenging and antioxidative activity of caffeic acid amide and ester analogues: structure–activity relationship. J Agric Food Chem 50:468–472PubMedCrossRefGoogle Scholar
  21. 21.
    Hocart HC, Fankhauser B, Buckle DW (1993) Chemical archaeology of kava, a potent brew. Rapid Commun Mass Spectrometry 7:219–224CrossRefGoogle Scholar
  22. 22.
    Zhu J, Majikina M, Tawata S (2001) Syntheses and biological activities of pyranyl-substituted cinnamates. Biosci Biotech Biochem 65:161–163CrossRefGoogle Scholar
  23. 23.
    Bilia AR, Scalise L, Bergonzi MC, Vincieri FF (2004) Analysis of kavalactones from Piper methysticum (kava-kava). J Chromatogr B 812:203–214Google Scholar

Copyright information

© The Japanese Society of Pharmacognosy and Springer 2007

Authors and Affiliations

  • Tran Dang Xuan
    • 1
  • Masakazu Fukuta
    • 1
  • Ao Chang Wei
    • 1
  • Abdelnaser Abdelghany Elzaawely
    • 1
  • Tran Dang Khanh
    • 2
  • Shinkichi Tawata
    • 1
  1. 1.Department of Bioscience and Biotechnology, Faculty of AgricultureUniversity of the RyukyusOkinawaJapan
  2. 2.Faculty of Crop ScienceKonkuk UniversitySeoulRepublic of Korea

Personalised recommendations