Piper methysticum is known as kava

Piper methysticum is a traditional beverage of various Pacific Basin countries. Piper methysticum has been introduced into the mainstream U.S. market principally as an anti-anxiety preparation. The effects of the long-term consumption of Piper methysticum have not been documented adequately. Preliminary studies suggest Piper methysticum consumption on a regular basis may cause liver harm.

Efficacy of extracting solvents to chemical components of kava Piper methysticum roots.
Nat Med (Tokyo). 2008 April. Xuan TD, Fukuta M, Wei AC, Elzaawely AA, Khanh TD, Tawata S. Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Okinawa, 903-0213, Japan.
The chemical composition of kava Piper methysticum lactones and various phytochemicals obtained following the sonication of ground Piper methysticum 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 Piper methysticum 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 Piper methysticum 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.

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