Intraspecific variation in essential oil composition of the medicinal plant Lippia integrifolia (Verbenaceae). Evidence for five chemotypes

• Published in: Phytochemistry (Oxford) Vol. 122; pp. 203 - 212
• Main Authors: Marcial, Guillermo, de Lampasona, Marina P., Vega, Marta I., Lizarraga, Emilio, Viturro, Carmen I., Slanis, Alberto, Juárez, Miguel A., Elechosa, Miguel A., Catalán, César A.N.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2016
• Subjects: Absolute configuration; Argentina; Artemisia; Biogenesis; Chemotypes; Essential oil; Gas Chromatography-Mass Spectrometry; Incayuyo; Lippia; Lippia - chemistry; Lippia - genetics; Lippia integrifolia; Molecular Structure; Monoterpene; Monoterpenes - chemistry; Nuclear Magnetic Resonance, Biomolecular; Oils, Volatile - chemistry; Plant Components, Aerial - chemistry; Plant Oils - chemistry; Plants, Medicinal - chemistry; Plants, Medicinal - genetics; Polymerase Chain Reaction; Sesquiterpene; Sesquiterpenes - chemistry; Stereoisomerism; Terpenes - chemistry; Terpenes - isolation & purification; trans-Davanone; Verbenaceae; Argentina; trans-Davanone; Lippia integrifolia; Verbenaceae; Incayuyo; Absolute configuration; Sesquiterpene; Monoterpene; Essential oil; Biogenesis; Chemotypes
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2015.11.004

The essential oil composition of 31 wild populations of Lippia integrifolia was analyzed. Using a hierarchical cluster analysis, five distinct chemotypes were detected, two of which are noteworthy by their unique chemical profiles: one characterized by high concentrations of trans-davanone and the other by containing rare sesquiterpenoids. [Display omitted] •Essential oil composition of 31 populations of L. integrifolia was analyzed.•Five chemotypes were characterized by PCA and AHC analysis.•The chemical profile of different chemotypes is largely under genetic control.•The absolute configuration of trans-davanone of L. integrifolia is 6S,7S,10S.•A biogenetic pathway to trans-davanone from (S)-trans-nerolidol is discussed. The aerial parts of Lippia integrifolia (incayuyo) are widely used in northwestern and central Argentina for their medicinal and aromatic properties. The essential oil composition of thirty-one wild populations of L. integrifolia covering most of its natural range was analyzed by GC and GC–MS. A total of one hundred and fifty two terpenoids were identified in the essential oils. Sesquiterpenoids were the dominant components in all but one of the collections analyzed, the only exception being a sample collected in San Juan province where monoterpenoids amounted to 51%. Five clearly defined chemotypes were observed. One possessed an exquisite and delicate sweet aroma with trans-davanone as dominant component (usually above 80%). Another with an exotic floral odour was rich in oxygenated sesquiterpenoids based on the rare lippifoliane and africanane skeletons. The trans-davanone chemotype is the first report of an essential oil containing that sesquiterpene ketone as the main constituent. The absolute configuration of trans-davanone from L. integrifolia was established as 6S, 7S, 10S, the enantiomer of trans-davanone from ‘davana oil’ (Artemisia pallens). Wild plants belonging to trans-davanone and lippifolienone chemotypes were propagated and cultivated in the same parcel of land in Santa Maria, Catamarca. The essential oil compositions of the cultivated plants were essentially identical to the original plants in the wild, indicating that the essential oil composition is largely under genetic control. Specimens collected near the Bolivian border that initially were identified as L. boliviana Rusby yielded an essential oil practically identical to the trans-davanone chemotype of L. integrifolia supporting the recent view that L. integrifolia (Gris.) Hieron. and L. boliviana Rusby are synonymous.