Chemical Variability of Wild Rosmarinus officinalis L. from Algeria

Rosemary (R. officinalis L.) is a Mediterranean shrub belonging to the Lamiaceae family. Wild rosemary, due to its bioactive properties, has been cultivated by local farmers, without any prior selection, for a long time. Specifically in Algeria, it occupies 100,000 ha of the territory; however, there is considerable lack of knowledge about the chemical variability of this wild rosemary. On the basis of these statements, a total of 15 wild Algerian rosemary populations have been analyzed, considering their essential oil yields (EO) and polyphenolic extract antioxidant activities (AA). Samples were harvested from natural populations located 30 km southwest of Saida. Statistically significant differences were detected among the EO yield of the different populations as well as among their antioxidant activities. Essential oil yield (v/w) ranged from 1.36 to 2.16%. To describe the antioxidant properties, the following were assessed: free radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH center dot) test, and the Ferric Reducing Antioxidant Power (FRAP). From the two methods applied, only FRAP showed a linear correlation (p<0.001; r:0.817) with respect to the total phenolic content of the extracts. However, the test which highlighted the greatest differences among the polyphenolic extracts was the DPPH center dot assay. These results will allow for preselection of the best populations with regards to EO yield and the highest AA. Related to this matter, the following populations will undergo vegetative propagations for their establishment as a commercial crop: I (2.16% EO yield; 11.12 mg gallic acid/g dry extract; 9.84 mM Fe+2/mg dry extract; 38.78 mu g dry extract/ml MeOH); IV (1.64% EO yield; 27.63 mg gallic acid/g dry extract; 11.51 mM Fe+2/mg dry extract; 61.52 mu g dry extract/ml MeOH); and VIII (1.57% EO yield; 11.43 mg gallic acid/g dry extract; 9.98 mM Fe+2/mg dry extract; 30.54 mu g dry extract/ml MeOH).