Ultra-High-Performance Liquid Chromatography with Photodiode Array and High-Resolution Time-of-Flight Mass Spectrometry Detectors (UHPLC-PDA-ESI-ToF/HRMS) for the Tentative Structural Characterization of Bioactive Compounds of Salvia verbenaca Extracts in Relation to Their Biological Activities

Background: Salvia verbenaca of the Lamiaceae family is a Mediterranean plant widely used in the Moroccan traditional folk medicine. The aim of this work was to explore the phytochemical composition of Salvia verbenaca extracts and its antioxidant activity. Methods: Separation and identification of the major phytochemicals present in the two hexane and ethyl acetate explored extracts have been achieved through ultra-high-performance liquid chromatography separation technique coupled to photodiode array and high-resolution time-of-flight mass spectrometry detectors. Antioxidant activity of the obtained extracts was evaluated through DPPH center dot (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2 '-azinobis(3-ethylbenzothiazoline6-sulfonic acid) diammonium salt) assays and the obtained results were compared to TROLOX (6-hydroxy2,5,7,8-tetramethylchroman-2-carboxylic acid). Results: Using the analysis technique indicated above, eighteen phytochemicals belonging to phenolic acids, phenolic diterpenes and flavonoids have been characterized on the basis of the obtained UV and mass spectroscopic properties and on the subsequent fragmentations. The antioxidant activity of the explored extracts showed potential scavenging activities compared to TROLOX. A detailed discussion of the attained results has been presented considering the activities observed of each extract. Conclusions: The research herein presented an analysis technique allowing to screen Salvia verbenaca phytochemicals. The explored plant could be considered as a source of functional phenolic compounds. These could be useful for further pharmacological studies such as new drugs design after clinic and its safety evaluation. It is thus hoped that the information presented here might prompt further studies that will possibly lead to development of therapeutic agents from this plant.