Exploring the Chemical Space of Kawakawa Leaf (Piper excelsum)

The chemical profiles of kawakawa (Piper excelsum) leaves were analysed through targeted and non-targeted LC-MS/MS. The phytochemical profile was obtained for both aqueous extracts representative of kawakawa tea and methanolic extracts. Sixty-four compounds were identified from eight leaf sources including phenylpropanoids, lignans, flavonoids, alkaloids and amides. Eight of these compounds were absolutely quantified. The chemical content varied significantly by leaf source, with two commercially available sources of dried kawakawa leaves being relatively high in phenylpropanoids and flavonoids compared with field-collected fresh samples that were richer in amides, alkaloids and lignans. The concentrations of pharmacologically active metabolites ingested from the traditional consumption of kawakawa leaf as an aqueous infusion, or from novel use as a seasoning, are well below documented toxicity thresholds.

Automated summary

The chemical profiles of kawakawa leaves were analyzed using targeted and non-targeted LC-MS/MS. Sixty-four compounds were identified, including phenylpropanoids, lignans, flavonoids, alkaloids, and amides. The concentrations of these compounds varied significantly depending on the source of the leaves. Ingesting kawakawa leaf as a tea or as a seasoning is unlikely to reach toxic levels of pharmacologically active metabolites.