Chemical Composition, Enantiomeric Distribution, and Sensory Evaluation of the Essential Oils Distilled from the Ecuadorian Species Myrcianthes myrsinoides (Kunth) Grifo and Myrcia mollis (Kunth) DC. (Myrtaceae)

Abstract

The essential oils of Myrcianthes myrsinoides and Myrcia mollis, belonging to the Myrtaceae family, were obtained by steam distillation. They were analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography-flame ionization detector (GC-FID), enantioselective gas chromatography, and gas chromatography-olfactometry (GC-O). A total of 58 compounds for Myrcianthes myrsinoides essential oil (EO) and 22 compounds for Myrcia mollis EO were identified and quantified by GC-MS with apolar and polar columns (including undetermined components). Major compounds (>5.0%) were limonene (5.3%–5.2%), 1,8-cineole (10.4%–11.6%), (Z)-caryophyllene (16.6%–16.8%), trans-calamenene (15.9%–14.6%), and spathulenol (6.2%–6.5%). The enantiomeric excess of eight chiral constituents was determined, being (+)-limonene and (+)-germacrene D enantiomerically pure. Eight components were identified as determinant in the aromatic profile: α-pinene, β-pinene, (+)-limonene, γ-terpinene, terpinolene, linalool, β-elemene and spathulenol. For M. mollis, the major compounds (>5.0%) were α-pinene (29.2%–27.7%), β-pinene (31.3%–30.0%), myrcene (5.0%–5.2%), 1,8-cineole (8.5%–8.7%), and linalool (7.7%–8.2%). The enantiomeric excess of five chiral constituents was determined, with (S)-α-pinene and (+)-germacrene D enantiomerically pure. The metabolites β-pinene, 1,8-cineole, γ-terpinene, terpinolene, linalool, and (E)-β-caryophyllene were mainly responsible for the aroma of the EO. Finally, the M. myrsinoides essential oil has an inhibitory activity for cholinesterase enzymes (IC50 of 78.6 μg/mL and 18.4 μg/mL vs. acethylcholinesterase (AChE) and butyrylcholinesterase (BChE) respectively). This activity is of interest to treat Alzheimer’s disease.

Essential Oils as a Potential Neuroprotective Remedy for Age-Related Neurodegenerative Diseases: A Review

“…All the methods recorded that 1,8-cineole was one of the compounds highest in antioxidant capacity. This finding was similar to several other types of research, which suggested the efficacy of 1,8-cineole as the dominant anticholinesterase agent from EOs of different sources [ 8 , 21 , 25 , 152 ].…”

Chemical Composition and Antioxidant Activity of Essential Oils from Eugenia patrisii Vahl, E. punicifolia (Kunth) DC., and Myrcia tomentosa (Aubl.) DC., Leaf of Family Myrtaceae

“…Specimens A and B of E. punicifolia had 0.26% and 0.14%, of EOs, respectively, while specimens A and B of M. tomentosa had EO contents of 0.35%, and 0.41%, respectively. These findings corroborate with those of several previous studies, which have suggested that the yields of EOs from different Myrtaceae species vary according to the studied species and the season of collection [20][21][22][23][24].…”

Chemical and Enantioselective Analysis of the Leaf Essential Oil from Piper coruscans Kunth (Piperaceae), a Costal and Amazonian Native Species of Ecuador

“…Among the natural products the authors are interested in, we can cite essential oils (EOs) [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. According to the European Pharmacopeia, an EO is an “odorous product, usually of complex composition, obtained from a botanically defined plant raw material by steam distillation, dry distillation, or a suitable mechanical process without heating.…”