Qualitative chemical characterization of salva-de-marajó (Lippia origanoides, Verbenaceae) preparations

Lippia origanoides Kunth (LO, Verbenaceae), commonly known in Brazil as salva-de-marajó, is an aromatic plant native to the Americas. Quilombola women from Oriximiná (Pará State, Brazil) use decoctions and decoction vapors of LO aerial parts orally or in sitz baths to alleviate symptoms of dysmenorrhea. This study aimed to evaluate LO decoctions and essential oils through a chemo-qualitative approach. Aerial parts of LO were collected from two individuals, and other two commercial samples were acquired from a public market. Aqueous extract of each sample was obtained by decoction and spray drying. The spray-dried decoctions were chemically characterized using UPLC-APCI(-)-IT-MS² and cluster heatmap analysis to discern compositional patterns. Essential oils were obtained through hydrodistillation and analyzed using GC-MS and GC-FID. In total, 12 compounds were tentatively identified from LO decoctions. Their product ion spectra were characteristic of flavonoid aglycones (5) and glycosides (4), and phenylpropanoids, including two stilbene glycosides and one hydroxycinnamic acid glycoside. Variations were noted in the chemical fingerprints of the decoctions, but the flavonoid glycosides orientin, isoorientin, and vitexin emerged as potential markers for the species. The essential oils of the samples contained high amounts of oxygenated monoterpenoids, with a predominance of the p-menthanes carvacrol (up to 61.9 %) and/or thymol (up to 17.0 %), and p-cymene (up to 24.9 %). This study was the first to explore the chemical composition of decoctions derived from LO, highlighting the species as an untapped source of phenolic glycosides, an aspect that has received limited discussion thus far.