Secondary metabolites profiling of Dracocephalum kotschyi Boiss at three phenological stages using uni-and multivariate methods

Variation in essential oil (EO) and phenolic compounds of Dracocephalum kotschyi Boiss plants was studied at three phenological stages. GC-MS analysis of the EO identified 15 components, with E-beta- ocimene as principal compound, whose percentage varied according to the phenological stage. main compounds identified were nerol at the vegetative, nerol/methylgeranate at flowering, and alpha-pinene/geranial/ geraniol at fruiting stage. In addition, 17 phenolic compounds were identified by LCDAD-ESI-MS in the different phenological stages. The profile of methoxylated flavonoids increased with the physiological age. The plant extracts containing the identified compounds showed significant antioxidant activity, which was correlated with the flavonoid and rosmarinic acid (RA) content. According to hierarchical cluster-(HCA)and principal component analysis (PCA), EOs and phenolic compound formed three groups separating from each other. Canonical correlation analysis was used to find a relationship between plant EOs and phenolic composition. (C) 2016 Elsevier GmbH. All rights reserved.