Essential Oil and Phylogenetic Positions of Five Medicinal Litsea Species (Lauraceae)

Litsea species have been used for herbal medicine by many ethnic groups. However, defining the morphological characteristics of the species remains difficult, leading to confusion and misuse of Litsea names. We examined Litsea classification, focusing on folk taxonomy. A field survey revealed that Litsea cubeba, L. elliptica, L. mollis, L. glutinosa, and L. martabanica have the highest use values. Using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS) analysis and multivariate statistical methods, we examined metabolites from these species to assess consistency across plant parts. Principal coordinate analysis (PCoA) and cluster analysis revealed distinct metabolite patterns, grouping species into four significant clusters: Group I (L. elliptica and L. martabanica), Group II (L. martabanica roots), Group III (L. cubeba and L. mollis bark and roots), and Group IV (L. glutinosa and L. cubeba and L. mollis leaves). Chemical compounds are clustered by species rather than by plant parts. Our study reveals a significant correlation (p < 0.05) between phylogenetic distances and chemical differences among Litsea species, elucidating the evolutionary links through metabolite variations. This predictive approach could help with more efficient selection for traditional medicine discovery and should be the first to be pharmacologically tested for drug development.