Volatile Fractions and Essential Oils of the Leaves and Branches of Dalea carthagenensis (Jacq.) J.F. Macbr. from Northern Region of Colombia

Abstract

Dalea carthagenensis L. is an American perennial sub-shrub, whose leaves/branches emit a soft pleasant odor. Due to its characteristic odor and the lacking literature reports on the chemistry of the volatile metabolites, in this work the composition by GC-MS of the volatile fractions and essential oils obtained by SDE/HS-SPME and MWHD, respectively, of the species collected in Colombia (Repelón, Atlántico), was established. As a result of the analysis, the main constituents identified in the volatile fractions were: (i.) SDE: leaves, (E)-β-ocimene/β-caryophyllene (each ∼21 %) and β-pinene (∼19 %); branches, (E)-β-ocimene (∼36 %), β-pinene (∼20 %) and trans-pinocarvyl acetate (∼14 %); (ii.) HS-SPME: branches/leaves, β-pinene (∼20-50 %) and β-caryophyllene (∼10-23 %). Likewise, the most abundant compounds found in the essential oils were: (iii.) dry season leaves (2013), trans-caryophyllene oxide (∼32 %) and β-pinene (∼13 %); (iv.) rainy season leaves (2014), β-pinene (∼16 %), (E)-β-ocimene (∼13 %) and trans-caryophyllene oxide/β-caryophyllene/myrcene (each ∼10 %); (v.) rainy season leaves (2017), (E)-β-ocimene (∼36 %), β-caryophyllene (∼21 %) and β-pinene (∼14 %); and finally, (vi.) branches (2017), trans-pinocarvyl acetate (∼29 %) and trans-caryophyllene oxide (∼22 %). From these results, it could be concluded that: i.) the complete profile of the volatile metabolites from leaves/branches of the plant was achieved, which is reported for the first time; and, ii.) the compositional variation of the essential oils was dependent on the collection time and the weather (dry/rainy season).