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

Abstract

Chemical bioprospecting is an important tool for generating knowledge regarding local human-threatened floras and for conservation management. For Baccharis L. (Asteraceae), several volatile components have been reported for Brazil, Argentina, Bolivia, and Chile as a result of bioprospection, but not for Uruguayan flora, which is composed of more than 50 native species. In this work, through collection of aerial parts of different species and volatile simultaneous-distillation extraction and gas chromatography-mass spectrometry analyses, twelve native species of Baccharis were studied (B. articulata, B. cultrata, B. genistifolia, B. gibertii, B. gnaphalioides, B. ochracea, B. phyteumoides, B. punctulata, B. crispa, B. dracunculifolia, B. linearifolia subsp. linearifolia, and B. spicata). A detailed analysis of the male and female volatile composition was conducted for the last four species. The profiles of B. cultrata, B. genistifolia, B. gibertii, and B. gnaphalioides are reported for the first time. Because half of the species analyzed in this work are in Uruguay and are threatened or potentially threatened by human economic activities, the importance of their conservation as natural, sustainable resources is highlighted.

Relationship between Baccharis dracunculifolia DC. and B. microdonta DC. (Asteraceae) by Their Different Seasonal Volatile Expression

“…Previously, we have analyzed the volatile extracts from a B. dracunculifolia wild population (male and female individuals separately) from Northern Uruguay (Paysandú province), [38] and those results are very different with the ones found here in Southern Uruguay. In the former case, the main compounds identified were: ( E )‐nerolidol (16.7 % and 17.3 % in male and female, respectively, and in this order hereafter), β‐pinene (10.5 % and 10.9 %), limonene (9.1 % and 8.9 %), spathulenol (5.5 % and 5.2 %), and α‐pinene (4.5 % and 3.9 %), among others [38] . The composition from Northern Uruguay resembles to the composition of commercial Brazilian ‘ vassoura ’ oils, [9,11] in higher contrast with the results from Southern Uruguay presented here ( Tables 2 and 3).…”

“…Into this classification, Southern Uruguayan populations belonged to the second category, despite the higher abundances of viridiflorol and the absence of ( E )‐nerolidol, compared with Brazilian populations (typical ‘ vassoura ’ oils) [10] . As shown in the Table 3, the influence of dioecism (i. e., male/female individuals in the populations) in B. dracunculifolia volatile expression is relevant, which highlights the need of carefully processes for sampling, extracting and analyzing separately the sexes [35,38,42,43] …”

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

“…Differences in the EO chemical compositions have been reported for B. punctulata collected from different geographical locations. The EOs of the samples collected from Uruguay have shown β-phellandrene (5.2%), bornyl acetate (5.2%), α-cadinol (4.2%), δ-elemene (3.7%), and the ketone shyobunone (3.5%) as the major compounds [ 36 ], whereas the EOs sourced in Guaíba, Brazil have comprised bicyclogermacrene (9.73%), cis-cadin-4-en-7-ol (6.77%), and (Z)-ocimene (6.33%) [ 23 ]. Of these compounds, only bornyl acetate (1.32%) and bicyclogermacrene (3.10%) were found in the present study in B. punctulata and in low concentrations.…”

Essential Oil Content of Baccharis crispa Spreng. Regulated by Water Stress and Seasonal Variation

“…There were differences in the number of identified volatile compounds in comparison to the values in the literature. In a study carried out in Southern Brazil [18], 85.1% of the primary components of the B. articulate volatile profile were identified, with 93.8% of them in B. cultrate, 59.5% in B. genistifolia, and 95.3% in B. gibertii. In some cases, the compounds were identified for the first time using an experiment conducted under various abiotic and hydric conditions.…”

“…Metabolites and essential oil yields in different medicinal and aromatic plants decrease under water-stress conditions [10,[13][14][15][16] and reduced irrigation frequency [11,12,17]. B. crispa is popularly recognized as carqueja in Brazil, and grows spontaneously in a wide range of soils and ecosystems in different Brazilian bioclimatic zones [18]. It is currently used as a medicinal plant and requires strict irrigation management to ensure a high yield and optimal quality in commercial farming systems [12].…”