This study aimed to characterize the in vitro antioxidant and antibacterial properties of oregano (Origanum vulgare) essential oil, as well as its chemical composition. To our best knowledge, there are few studies on oregano grown in the arid Andes region, but none on the metabolites produced and their bioactivity. This work identified fifty metabolites by Gas Chromatography–Mass Spectrometry (GC-MS)—monoterpene hydrocarbons, oxygenated monoterpenes, phenolic monoterpenes, sesquiterpene hydrocarbons, and oxygenated sesquiterpenes—present in the essential oil of oregano collected in the Atacama Desert. The main components of essential oregano oil were thymol (15.9%), Z-sabinene hydrate (13.4%), γ-terpinene (10.6%), p-cymene (8.6%), linalyl acetate (7.2%), sabinene (6.5%), and carvacrol methyl ether (5.6%). The antibacterial tests showed that the pathogenic bacteria Staphylococcus aureus and Salmonella enterica and the phytopathogenic bacteria Erwinia rhapontici and Xanthomonas campestris were the most susceptible to oregano oil, with the lowest concentrations of oil necessary to inhibit their bacterial growth. Moreover, oregano oil showed antibacterial activity against bacteria associated with food poisoning. In conclusion, O. vulgare from the arid Andean region possesses an important antibacterial activity with a high potential in the food industry and agriculture.

High-resolution mass spectrometry is currently used to determine the mass of biologically active compounds in medicinal plants and food and UHPLC-Orbitrap is a relatively new technology that allows fast fingerprinting and metabolomics analysis. Forty-two metabolites including several phenolic acids, flavonoids, coumarines, tremetones and ent-clerodane diterpenes were accurately identified for the first time in the resin of the medicinal plant (Asteraceae) a Chilean native species, commonly called umatola, collected in the pre-cordillera and altiplano regions of northern Chile, by means of UHPLC-PDA-HR-MS. This could be possible by the state of the art technology employed, which allowed well resolved total ion current peaks and the proposal of some biosynthetic relationships between the compounds detected. Some mayor compounds were also isolated using HSCCC. The ethanolic extract showed high total polyphenols content and significant antioxidant capacity. Furthermore, several biological assays were performed that determined the high antioxidant capacity found for the mayor compound isolated from the plant, 11--coumaroyloxyltremetone.

Continuing with our study characterising Senecio nutans Sch. Bip., we have isolated and identified a simple coumarin, scopoletin, that could be relevant for the biological properties of the species related with the ancestral medical uses. This is the first report of scopoletin from S. nutans. In addition, the extract was analysed for its antioxidant activity using the ABTS and FRAP method as well as providing the first nutritional analyses of this plant from northern Chile highlands.

A general effective organocatalyzed synthesis of enantioenriched morphans with up to 92% ee was developed. The morphan scaffold was constructed in a one-pot tandem asymmetric organocatalyzed Michael addition followed by a domino Robinson annulation/aza-Michael intramolecular reaction sequence from easily available starting materials.

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