Campovassouria cruciata (DC)

de Souza, Tiago J. T., S, Bordignon, ergio A. L., Apel, Miriam A. & Henriques, Amelia T., 2021, Volatile constituents of Eupatorieae (Asteraceae). Compositional multivariate analysis of volatile oils from Southern Brazilian species in the subtribe Disynaphiinae, Phytochemistry (112734) 186, pp. 1-23 : 15

Two samples of Campovassouria cruciata

(syn. C. bupleurifolia , Eupatorium bupleurifolium

- common name: “vassoura-do-campo”), a

1.0– 2.5 m tall branchy shrub, native to the humid fields of Southern Brazil, Bolivia, Paraguay, Northern Argentina, and Uruguay were obtained in Sao ˜ Francisco de Paula and Morro Reuter, RS, in 2005, during the flowering season ( Table S1 ). The VO content varied from 0.2 to 0.4%. Sixty components were identified in the oils obtained from the leaves and inflorescences from two samples (91.1–97.9% of the total). VOs in the inflorescences and leaves of the first sample were characterized by the predominance of oxygenated sesquiterpenes (74.6 and 64.1%), including caryophyllene oxide (25.2 and 28.2%), globulol (14.8 and 20.1%), and epiglobulol (15.4 and 14.1%). The second sample showed similar percentages for the monoterpenes and sesquiterpenes in the leaves (49.6% and 47.5%) with the predominance of sesquiterpenes in the inflorescences (68.4%). The monoterpene fraction was composed of almost exclusively hydrocarbon compounds, mainly α- pinene (12.1 and 15.5%), sabinene (5.1 and 8.9%), β- pinene (4.8 and 7.2%), and limonene (3.4 and 8.1%). In the sesquiterpene fraction, both hydrocarbon and oxygenated compounds occurred (37.1% and 31.3% in inflorescences and 27.2% and 20.3% in leaves, respectively). The major compounds in the sesquiterpene fraction of the VOs in the second sample were β- caryophyllene (12.6 and 13.4%) and germacrene D (10.2 and 6.4%). The VOs obtained from both the leaves and inflorescences of both samples showed qualitatively similar chemical compositions, except for the absence of D germacrene and bicyclogermacrene in the sample from S˜ao Francisco de Paula. These two hydrocarbon compounds can undergo different chemical and enzymatic rearrangements and oxidations, resulting in several different sesquiterpenes and sesquiterpenoids (Bülow and K¨onig, 2000; Toyota et al., 1996; Venturi et al., 2015). Thus, compounds in the sesquiterpene fraction of the VOs from both samples of C. cruciata mainly originate from the caryophyllane and germacrane biogenetic pathways. This melliferous species is widely visited by bees ( Gonçalves and Melo, 2005) Apis mellifera and Bombus (Fervidobombus) pauloensis (Apidae) in Southeastern Brazil ( Gonçalves et al., 2009) and Pseudagapostemon sp. ( Krug et al., 2010) and Plebeia remota (Halictidae) in Southern Brazil ( Steiner et al., 2010). It is an important species in the reproductive biology of black-bellied seedeaters ( Sporophila melanogaster ) ( Rovedder and Fontana, 2012). It has also been reported to have medicinal use in Argentina ( Hilgert and Gil, 2006). Guaiagrazielolide-type sesquiterpene lactones were isolated from the extracts of this plant ( Bohlmann et al., 1983). VO production was reported to be 1.40–1.77% (dry and fresh inflorescences, respectively), but the chemical composition has not been previously reported ( Souza, 2015). The absence of reports on C. barbosae and on C. cruciata from other locations prevent further discussion on the volatile chemistry of this genus. However, it is noteworthy that the composition described herein for C. cruciata is qualitatively similar to that described for Raulinoreitzia crenulata and Grazielia spp. in the hydrocarbon fraction, differing in the proportion of oxygenated sesquiterpenes, which are qualitatively different from those in Raulinoreitzia tremula .