Montalvan_2019_Plants.(Basel)_8_

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: alpha-pinene, beta-pinene, (+)-limonene, gamma-terpinene, terpinolene, linalool, beta-elemene and spathulenol. For M. mollis, the major compounds (>5.0%) were alpha-pinene (29.2%-27.7%), beta-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)-alpha-pinene and (+)-germacrene D enantiomerically pure. The metabolites beta-pinene, 1,8-cineole, gamma-terpinene, terpinolene, linalool, and (E)-beta-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 mug/ml and 18.4 mug/ml vs. acethylcholinesterase (AChE) and butyrylcholinesterase (BChE) respectively). This activity is of interest to treat Alzheimer's disease.