Comparative chemistry and biological properties of the solid residues from hydrodistillation of Spanish populations of Rosmarinus officinalis L.

Solid residues from the hydrodistillation of selected Spanish populations of rosemary (Rosmarinus officinalis L.) have been analyzed for their polyphenol composition, and antioxidant and bioplaguicide activities. The objective was to evaluate and select the most suitable plant materials as sources of natural antioxidants and crop protectants. Total polyphenol content and polyphenol composition of rosemary populations were very dependent on the growth location: populations from Aranjuez showed a higher content of total polyphenols and were richer in rosmarinic acid as compared with their equivalent populations from Cuenca, whereas these latter were characterized by an overall higher content in genkwanin and carnosol. Most of the antioxidant activities were highly correlated with the total content of polyphenols although some polyphenols like carnosic acid and carnosol seemed to favor such activities. The extracts from R. officinalis were strong antifeedants against Leptinotarsa decemlineata Say and moderate against Spodoptera littoralis Boisd and Myzus persicae Sulzer, according to their feeding ecologies. The biological effects of the active samples cannot be accounted by their chemical composition, suggesting additive or synergistic effects. Both the phytotoxic and stimulating effects on Lactuca sativa L., and Lolium perenne L. leaf and/or root growth were observed.