An innovative approach to the recovery of phenolic compounds and volatile terpenes from the same fresh foliar sample of Rosmarinus officinalis L.

Rosmarinus officinalis L. is a plant of relevant commercial interest because of its volatile fraction and also its phenolic constituents which are both well known for their numerous properties. Nevertheless, an extractive method suitable to recovering both the aromatic and phenolic fractions from the same fresh foliar tissue has not yet been reported. In this work we have optimized a two-step procedure able to recover first the phenolic compounds and successively the volatile terpenes from the same foliar sample. The recovery of the whole phenolic fraction, partially degraded using a traditional extractive method, was guaranteed and we observed a significant increment in the amount of volatile terpenes compared to a traditional extraction procedure. We also highlight crucial information on the enzymatic activity of the endogenous oxidases that rapidly transform the phenolic substrates, mainly the rosmarinic acid. Our results suggest that this extractive procedure could also be used for other aromatic plants, thus providing a useful tool for more complete analyses of the main phytochemicals available in fresh foliar samples and creating the possibility of incrementing yields of volatile compounds.