Exploring the effects of post-distillation and post-supercritical CO2 extraction on chemical profile and biological activities of two Salvia species (S. chrysophylla and S. microstegia)

In this paper the extraction of phytoconstituents from Salvia chrysophylla and S. microstegia aerial parts was performed using maceration, supercritical carbon dioxide extraction (SCO2) and hydrodistillation. Additionally, the residual material from hydrodistillation and SCO2 was evaluated for the content in secondary metabolites. To achieve these goals Nuclear Magnetic Resonance (NMR) spectroscopy, liquid chromatography coupled with diode array and multiple stage mass spectrometry (LC-DAD-MSn) and liquid chromatography coupled with high resolution quadrupole time of flight mass spectrometry (LC-HR-QTOF) were used for the analysis of non-volatile compounds. Gas chromatography coupled with mass spectrometry (GC–MS) was adopted for the essential oil analysis. Main constituents were rosmarinic acid and luteolin-7-O-glucopyranoside, in S. microstegia while sclareol and salvigenin in S. crisophylla. Regarding essential oil composition terpine-4-ol-acetate and caryophyllene oxide were the most abundant constituents in S. microstegia and S. chrysophylla respectively. Subsequently, we determined the antioxidant capacity using different chemical assays. To establish potential other bioactivities inhibition on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, α-amylase and α-glucosidase, was examined. The findings revealed the water extract (WE) and methanol total extract (TE) of S. microstegia extracts, exhibited higher total phenolic contents and antioxidant activity compared to S. chrysophylla extracts. Moreover, both S. microstegia and S. chrysophylla essential oils EOs displayed significant phosphomolybdenum (PBD) activity, and their acetylcholinesterase (AChE) inhibitory activity was notably elevated and nearly equivalent, measuring 2.79 mg GALAE/g and 2.78 mg GALAE/g, respectively. These findings underscore the potential for diverse applications of these plant extracts in various industries, including pharmaceuticals and cosmeceuticals.