Variations in the Chemical Composition of Essential Oils in Native Populations of Korean Thyme, Thymus quinquecostatus Celak.

Abstract

The genus Thymus (Lamiaceae) contains numerous medicinally important species. Among them, Thymus quinquecostatus Celak. has been extensively utilized as a traditional medicine and a food flavoring agent in the Korean peninsula, owing to its unique aroma. In particular, T. quinquecostatus has been used for the treatment of gastroenteritis, inflammation, stomach problems, liver disease, arthritis, arteriosclerosis, and menstrual problems. This study aimed to investigate the chemical diversity of essential oils among 103 Korean native populations of T. quinquecostatus. For this purpose, seedlings of T. quinquecostatus populations were purchased from different regions in the Korean Peninsula, and seedlings were grown in the experimental field under the same environmental conditions. The chemical compositions of steam-distilled essential oils were determined using GC-MS. In total, 212 components were identified from 103 populations of T. quinquecostatus. Furthermore, principal component analysis (PCA) was performed in order to understand variations in the essential oil compositions among 103 Korean native populations of T. quinquecostatus. According to the essential oil compositions, 30 components were selected for PCA. Based on the most abundant essential oil components, four chemotypes were identified in T. quinquecostatus populations. PCA and cluster analyses revealed that 103 individuals of T. quinquecostatus could be classified into four clusters, such as thymol, geraniol, geranyl acetate, and linalool. Furthermore, dendrogram construction demonstrated that geraniol and geranyl acetate, as well as linalool and thymol groups, were closely related. This study suggested the significant chemical polymorphism of essential oils in local populations of T. quinquecostatus in Korea. It could be concluded that the intraspecific variations in the essential oil compositions may be associated with genetic diversity among the individuals.

Exploring Chemical Variability in the Essential Oils of the Thymus Genus

“…A study on 103 Korean populations of Thymus quinquecostatus revealed different chemotypes characterized by dominant compounds in the essential oil, including thymol, geraniol, geranyl acetate, and linalool. The chemical polymorphism observed among thyme populations was associated with the genetic diversity of individuals [85]. Substantial variability was observed in the 'Standard Winter' cultivar of Thymus vulgaris, showing diverse chemical compositions of the essential oil and in phenolic acids (caffeic acid, rosmarinic acid and p-Coumaric acid) and flavonoids contents [86].…”

Multivariate Analysis of Essential Oil Composition of Artemisia annua L. Collected from Different Locations in Korea

“…Therefore, it is important to understand the chemical composition of essential oils of A. annua collected from different geographical regions. Multivariate analysis is an important statistical analysis method to determine and classify the chemical or morphological characteristics of plant species by cluster analysis and principal component analysis [ 15 , 16 , 17 ]. Previously, Radulović et al [ 18 ] grouped AEOs into four classes based on multivariate analysis.…”