Optimized ultrasound-assisted extraction of phenolic compounds from Thymus comosus Heuff. ex Griseb. et Schenk (wild thyme) and their bioactive potential
An optimized ultrasound-assisted extractive method was developed to obtain a polyphenol-enriched extract from
the aerial parts of Thymus comosus Heuff. ex Griseb. et Schenk. Optimization process was conducted based on
Design of Experiment (DoE) principles, determining the influence of three independent variables (time, ultrasound
amplitude, ethanol concentration) on the total phenolic content of the extract (dependent variable).
Additionally, the phenolic composition of the extract was characterized through UHPLC-HRMS, revealing beside
the most abundant flavonoid-type compounds the presence of salvianolic acids C, D and L in high amounts.
Phytochemical profile of the extract was correlated with its antioxidant activity (tested through five complementary
assays) and enzyme-inhibitory potential, showing important antiglucosidase and anticholinesterase
effects. Overall, it was concluded that the developed method is suitable for obtaining a good recovery of both
phenolic and non-phenolic compounds from Thymus comosus aerial parts, and their presence in the optimized
extract is responsible for its pharmacological potential.
This work was supported by a grant of the Romanian Ministry of
Education and Research, CNCS – UEFISCDI, project number PN-III-P1-
1.1-PD-2019-1245, within PNCDI III”. The authors are grateful to the
Foundation for Science and Technology (FCT, Portugal) for financial
support through national funds FCT/MCTES to CIMO (UIDB/00690/2020), and for the contracts of J. Pinela (CEECIND/01011/2018) and L.
Barros (institutional scientific employment program-contract).
