Essential Oils from Origanum vulgare subsp. virens (Hoffmanns. & Link) Ietsw. Grown in Portugal: Chemical Diversity and Relevance of Chemical Descriptors

• Published in: Plants (Basel) Vol. 12; no. 3; p. 621
• Main Authors: Machado, Alexandra M, Lopes, Violeta, Barata, Ana M, Póvoa, Orlanda, Farinha, Noémia, Figueiredo, A Cristina
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31.01.2023; MDPI
• Subjects: Carvacrol; chemical descriptors; chemotypes; Cluster analysis; Crop production; Cuttings; Essential oils; Gas chromatography; Harvesting; Herbal medicine; Linalool; Mass spectrometry; Mass spectroscopy; medicinal and aromatic plants; Medicinal plants; Monoterpenes; Morphology; Ocimene; Oils & fats; Oregano; Origanum vulgare virens; p-Cymene; Terpinene; Thymol; Portugal; chemotypes; chemical descriptors; medicinal and aromatic plants; essential oils; oregano
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants12030621

L. is a well-known aromatic and medicinal plant, whose essential oil (EO) has recognised flavouring and medicinal properties. In this study, subsp. (Hoffmanns. & Link) Ietsw. EOs, isolated from accessions grown in experimental fields, were evaluated. The plant material was grown from rooted cuttings or nutlets (fruits), originally collected in 20 regions in mainland Portugal and harvesting for EO isolation was performed in two years. EOs were isolated by hydrodistillation and analysed by gas chromatography and gas chromatography-mass spectrometry, for EO quantification and identification, respectively. EO yields ranged from <0.05-3.3% for rooted cuttings, with oregano samples obtained in Portalegre and Alandroal, respectively. Ninety-one compounds were identified, mainly grouped in oxygen-containing monoterpenes and monoterpene hydrocarbons. EO agglomerative cluster analysis evidenced two main clusters, with the first subdivided into four subclusters. From the obtained data, the putative subsp. chemotypes are carvacrol, thymol and linalool, with γ-terpinene, -cymene, - and -β-ocimene also contributing as these EOs chemical descriptors. The comparison between the present data and a survey of the existing literature on Portuguese reinforces the major variability of this species' EOs and emphasises the importance of avoiding wild collections to obtain a defined chemical type of crop production of market relevance.