Recent Findings in the Chemistry of Odorants from Four Baccharis Species and Their Impact as Chemical Markers

Abstract

Baccharis is a widespread genus belonging to the Asteraceae family that includes almost 400 species exclusively from the Americas. Even when studied in detail, the taxonomic classification among species from this genus is not yet fully defined. Within the framework of our study of the volatile composition of the Baccharis genus, four species (B. trimera, B. milleflora, B. tridentata, and B. uncinella) were collected from the 'Campos de Cima da Serra' highlands of the Brazilian state of Rio Grande do Sul. The aerial parts were dried and extracted by the simultaneous distillation extraction (SDE) procedure. This is the first time that SDE has been applied to obtain and compare the volatile-extract composition in the Baccharis genus. Characterization of the volatile extracts allowed the identification of 180 peaks with many coeluting components; these latter being detailed for the first time for this genus. The multivariate statistical analyses allowed separating the volatile extracts of the four populations of Baccharis into two separate groups. The first one included the B. milleflora, B. trimera, and B. uncinella volatile extracts. The three species showed a high degree of similarity in their volatile composition, which was characterized by the presence of high contents of sesquiterpene compounds, in particular of spathulenol. The second group comprised the extract of B. tridentata, which contained α-pinene, β-pinene, limonene, and (E)-β-ocimene in high amounts.

Volatile Constituents fromBaccharisspp. L. (Asteraceae): Chemical Support for the Conservation of Threatened Species in Uruguay

“…In addition, linear retention indices were calculated by analysing a homologous n ‐alkane series (alkane analytical standard solution C 8 – C 20 ; Sigma–Aldrich ) with the same experimental conditions as the samples. These values were compared with those from the literature and with our previous bioprospecting study . Quantification of each compound was performed on the basis of their GC peak areas, without corrections for response factor.…”

“…Recently, our group studied, with the same aim, four Baccharis spp. from Campos de Cima da Serra (Rio Grande do Sul, Brazil), a highland environment of the Ombrophilus Mixed Forest, which is highly threatened by human exploitation …”

“…spicata (F, female and M, male) . LRI e and LRI b: linear retention indices in HP‐5MS in experimental conditions and bibliography , respectively. The components are ordered in increasing LRI e values.…”

“…The plant material (50 – 120 g, depending on availability) was extracted for 120 min in a laboratory modified Likens–Nickerson apparatus employing hexane (analytical grade; Dorwil S.A ., Buenos Aires, Argentina) as extraction solvent . Prior to the extraction, aerial parts of B .…”

Essential Oils of Five Baccharis Species: Investigations on the Chemical Composition and Biological Activities

“…Monoterpenoids and sesquiterpenoids are frequently found in the EOs of Baccharis [ 3 , 30 ]. Sesquiterpenoids seemed to be more abundant in the majority of the species [ 3 , 6 , 7 , 16 , 22 , 30 , 31 , 32 , 33 ]. However, the EO of some species contained more monoterpenoids than sesquiterpenoids, such as in B. obovata [ 21 ], B. schultzii , B. regnelli Sch.…”