Identification by methane chemical ionization gas chromatography/mass spectrometry of the products obtained by steam distillation and aqueous acid extraction of commercial Piper methysticum

Bornyl cinnamate has been identified as a constituent of kava resin and of the steam distillate of Piper methysticum. 5‐Hydroxydihydrokawain was identified in commercial samples of P. methysticum originating from Vanuatu provided an initial aqueous extraction was employed. Commercial preparations, and fresh samples of the root of this plant from Fiji, lacked this compound. Two previously described N‐cinnamoyl pyrrolidine alkaloids were also observed along with stigmasterol in kava resin from Fiji and Vanuatu. The products derived from aqueous 2 M hydrochloric acid extraction of P. methysticum were determined from methane chemical ionization gas chromatography/mass spectrometry analysis which identified a series of hydroxylated compounds (15a–d) derived from formal decarbonylation of the parent kava lactones. The products (13a–c) of dehydration of these compounds were also observed. The efficiency of kava resin extraction from plant material by water (the traditional method of preparation of the kava beverage) was typically 5–10% of that recovered by direct extraction with an organic solvent.