Hplc-dad-esi+-ms phytochemical profiles of several rosmarinus officinalis accessions from Spain as influenced by different environmental stress conditions

Abstract

Rosemary, a native Mediterranean plant is a well-known source of phytochemicals with antioxidant activity attributed mainly to diterpenoids and flavonoids. The aim of the study was to establish an accurate evaluation of the rosemary metabolite profiles from several accessions under changing environmental conditions (water stress and soil salinity) comparing two sampling seasons (summer vs. spring) from four different habitats in Eastern Spain. The methodology was based on the identification and the quantitative evaluation of phytochemicals (phenolic acid derivatives, flavonoids, diterpenes and triterpenes) by HPLC coupled with diode-array detection and electrospray ionization mass spectrometry (ESI+-MS). Phytochemical profiles were statistically compared by factorial ANOVA, cluster analysis, principal component analysis and univariate analysis (Pearson correlations), that allowed the discrimination between the extract composition in correlation to their habitat and stress conditions. Out of twenty-three compounds identified, the major ones were represented by diterpenoids (carnosic acid, carnosol and oxidized metabolites rosmanol, epirosmanol, rosmadial, rosmanol methyl ether) and flavonoids, which showed significant metabolic regulation induced by water stress. The main conclusion of the work is that the diterpene derivatives and their oxidized metabolites may be considered as optimal biomarkers of the environmental stress in Rosmarinus officinalis.