## 3 Discussion  
Herbal extracts bioactivity depends on their chemical profile and the choice of the solvent is crucial in extraction processes as it directly affects the chemical composition of the final extracts and the mass extraction yield. Among the alternative solvents available for plants extraction, hydro-alcoholic mixtures are good candidates since they are rather few selective and let to extract a wide range of compounds [34; 35; 36; 37]. Considering global extraction yields of _Rosmarinus officinalis_, a ratio ranging from 50% to 80% ethanol gives highest mass extraction yields and total content in target compounds in comparison to lower Et-OH values. For this reason, the solvent that we utilized for the production of _R_oex was hydro-alcoholic mixture with 60% ethanol which yielded 112 mg of dry extract from  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{_Salmonella typhimurium TA 98_} & _Salmonella typhimurium_ **TA 100** \\ \hline  & \multicolumn{2}{c}{**Revertant (Mean \(\pm\) SD)**} & \multicolumn{2}{c}{**Revertant (Mean \(\pm\) SD)**} \\ \hline \multicolumn{2}{c}{_R_oex d.e. Concentration**} & \multirow{2}{*}{\(-\)**S9**} & \multirow{2}{*}{\(+\)**S9**} & \multirow{2}{*}{\(-\)**S9**} & \multirow{2}{*}{\(+\)**S9**} \\ \cline{1-1} \cline{5-5}
0 & & & & \\ \cline{1-1  
each gram of rosemary subjected to extraction, corresponding to a percentage yield of 11.2%. This lower percentage yield obtained in comparison to data reported by [PERSON] et al. [38] can be probably due to the environmental conditions as _Rosmarinus officinalis_ is a sensitive plant to pedoclimatic variations that affect its chemical composition [30]. The _Roe_x, showed a high total phenolic content, of about 95.8 mg/g dry extract, equivalent to 8.55 mg/g dry herbal material ca., in accordance with other extracts obtained from Mediterranean rosemary [21]. As previously reported for other rosemary [22; 39], also in _Roe_x the main phenolic subclass was identified in hydroxycinnamic acid derivatives, and rosmarinic acid was the main single compound, counting almost the half of total phenolic content. Still in accordance with other published papers, also in _Roe_x total flavonoid content was low, about 6.5 mg/g. This analysis of the phenolic composition of the Italian rosemary extract, performed by means of HPLC-DAD technique, represents a good characterization of its phenolic fingerprint and demonstrated the range of molecules contributing to the definition of this matrix, and may assist in the study of its in vitro bioactive properties [8]. Surprisingly, we found also a high content in triterpenoids in _Roe_x, 71.7 mg/g extract. Factors such as plant age, climate and stress conditions that inhibit or enhance the production of certain compounds might affect the chemical composition of the extracts [40]. These factors influence the metabolites qualitatively and quantitatively and may explain why certain compounds such as quercetin, rutin and other quercetin glycosides were not detectable in this study [40]. The good in vitro antioxidant activity in cell free assays showed by _Roe_x, demonstrated both by its ability to scavenge the free DPPH radical via electron donation and by the capability to scavenge hydrogen peroxide in a concentration dependent manner (Figure 2), is very similar to others typical vegetal extracts with a good antiradical power [41], and is a consequence of its phytocompounds composition. Hydroxycinnamic acids, presents in high concentration in _Roe_x, are potent antioxidants and, among them, rosmarinic acid and caffeic acid have a good dose-dependent DPPH scavenging activity and may contribute to the antiradical activity of the extract [42], together with rosmarinic acid. Moreover, also flavonoids and their metabolites are able to scavenge radicals and participate in antioxidant reactions as well as triterpenoids and total phenolic compounds [42].