In this research, the leaves of Lepechinia heteromorpha (Briq.) Epling, Lepechinia radula (Benth.) Epling and Lepechinia paniculata (Kunth) Epling have been collected in order to perform a phytochemical study. The first species was distilled to obtain a novel essential oil (EO), while the others were submitted to ethyl acetate extraction and secondary metabolite isolation. The chemical composition of the EO from L. heteromorpha has been investigated by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography with Retention Indices (GC(RI)), identifying 25 constituents. A major compound, (−)-ledol (21.2%), and a minor compound, (−)-caryophyllene oxide (1.0%), were isolated from the EO and their structures confirmed by Nuclear Magnetic Resonance (NMR) spectroscopy. Other major constituents of the EO were viridiflorene (27.3%), (E,E)-α-farnesene (1.4%), spirolepechinene and (E)-β-caryophyllene (7.1% each), allo-aromadendrene (6.1%), camphor (1.7%), limonene (1.3%) and β-phellandrene (4.6%). The enantiomeric composition of the EO monoterpene fraction was also studied, determining the enantiomeric excess and distribution of α-pinene, limonene, β-phellandrene and camphor. The ethyl acetate extract of L. radula and L. paniculata were fractionated by column chromatography. Spathulenol, angustanoic acid E and 5-hydroxy-4′,7-dimethoxy flavone were isolated from L. radula extract; ledol, guaiol and (−)-carnosol were found in L. paniculata.

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.

An essential oil was distilled with 0.25% yield from fresh flowers of Dalea mutisii Kunth, a native species mainly growing in the Andean region of Ecuador. A total of 50 compounds were identified, and most of them were quantified. The chemical composition was characterized by the prevalence of monoterpene hydrocarbons (>90%). Major components were α-pinene (42.9%), β-pinene (15.1%), β-phellandrene (12.6%), myrcene (6.7%), and (Z)-β-ocimene (5.4%). The essential oil was then submitted to enantioselective analysis, with a 2,3-diethyl-6-tert-butyldimethylsilyl-β-cyclodextrin-based capillary column. An enantiomeric excess was measured for (1R,5R)-(+)-α-pinene (91.6%), (1R,5R)-(+)-β-pinene (15.2%), (R)-(−)-α-phellandrene (4.8%), and (R)-(−)-β-phellandrene (88.8%), whereas (R)-(+)-limonene was enantiomerically pure. A gas chromatography–olfactometry (GC–O) analysis was additionally carried out on this pleasantly fragrant essential oil, following an aroma extract dilution analysis (AEDA) approach. Main odorants were α-pinene, β-pinene, α-phellandrene, and (Z)-β-ocimene, with dilution factors (FD) of 8, 4, 2, and 2, respectively.

The traditional Ecuadorian spice Ishpingo, characterized by a strong cinnamon-like aroma, is constituted by the dry cupules of Amazonian species Ocotea quixos. Nevertheless, bark and leaves also present aromatic properties and are sometimes used as substitutes. In the present study, the essential oils, distilled from these morphological structures, are comparatively analyzed for their chemical and enantiomeric compositions. A total of 88 components were identified with 2 orthogonal GC columns, whereas 79, corresponding to more than 94%, were also quantified with at least 1 column. Major compounds were (E)-methyl cinnamate in cupules (35.9–34.2%), (E)-cinnamaldehyde in bark (44.7–47.0%), and (E)-cinnamyl acetate (46.0–50.4%) in leaves. For what concerns the enantioselective analysis, 10 chiral terpenes and terpenoids were detected, of which 6 were present as enantiomeric pairs in at least 1 essential oil, the others being enantiomerically pure. Both quantitative and enantioselective analyses were submitted to Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), where their results confirmed significative difference among the three products.

Termites are one of the most challenging pests that agriculture and urban environments are faced with. They bring substantial losses in annual and perennial crops and damage wood components at construction sites. The development of natural products with biological activity for termite control is an ecological alternative in the search to replace conventional products. Hence, the aim of this research was to predict the termiticidal and repellent effects of the essential oil from Ocotea quixos leaves on Nasutitermes corniger using a one-factor response surface methodology design. The variable analysed was the concentration of essential oil in ethanol at an interval of 0.3–0.05% for anti-termite activity and between 0.12 and 0.01% for repellent action. A 100% mortality rate was found at concentrations higher than 0.12% and at the minimum concentration analysed, the effect was 22.2%. As for the repellent action, the concentration of 0.12% was able to repel 100% of the termites and at 0.01% it repelled 48.9%. The analysis of the essential oil from Ocotea quixos leaves by GC-MS resulted in the presence of 42 compounds, 39 of them elucidated. The main compounds were (E)-cinnamyl acetate (36.44%), (E)-cinnamaldehyde (27.03%), (E)-β-caryophyllene (5.21%) and (E)-methyl isoeugenol (4.18%).