Optimized ultrasound-assisted extraction of phenolic compounds from Thymus comosus Heuff. ex Griseb. et Schenk (wild thyme) and their bioactive potential

Optimized Ultrasound-Assisted Enzymatic Extraction of Phenolic Compounds from Rosa canina L. Pseudo-Fruits (Rosehip) and Their Biological Activity

“…The UHPLC was based on the utilization of a Waters BEH C18 column (2.1 × 100 mm, 1.7 μm). The mass spectrometry conditions were adapted from a previously published work [ 22 ]. Briefly, the flow rate was 200 μL/min; the injection volume was 6 μL; the full scan MS-data-dependent (Top n = 3) MS/MS mode was used for ion acquisition in the range 80–1200 m/z , with a positive ionization mode and a mass resolution of 70,000 FWHM.…”

“…For TEAC, an ABTS + radical solution was prepared by reacting 7 mM ABTS solution with 2.45 mM potassium persulfate, and then the mixture was left in the dark at room temperature for 12–16 h. The ABTS+ radical solution was diluted until an absorbance of 0.70 ± 0.02 at 734 nm, and then 200 μL of radical solution were added to 20 μL of the sample (at a 1 mg/mL concentration). After 30 min of incubation in the dark at room temperature, the absorbances were read at 734 nm, and the results were expresses as milligrams of Trolox equivalents per g of freeze-dried powder (mg TE/g dw) [ 21 , 22 ].…”

“…For the FRAP assay (ferric reducing antioxidant power), the FRAP reagent was prepared by mixing acetate buffer (0.3 M, pH 3.6), 2,4,6-tris(2-pyridyl)- S -triazine (TPTZ) (10 mM), and 40 mM HCl and ferric chloride (20 mM) in a ratio of 10:1:1 ( v/v/v ). Then, 175 μL of radical solution was added to 25 μL of the sample (at a 1 mg/mL concentration), and the absorbance was read at 593 nm after a 30 min incubation at room temperature and in the dark, the activity being expressed as milligrams of Trolox equivalents per g of freeze-dried powder (mg TE/g extract) [ 21 , 22 ].…”

“…After 15 min of incubation at room temperature, 40 μL of the substrate (L-DOPA, 2.5 mM in phosphate buffer) was added, and the reaction mixture was re-incubated for 10 min in the same conditions. The absorbance values were measured at 492 nm, and the results were expressed in terms of IC 50 (μg/mL), using kojic acid as positive control [ 21 , 22 ].…”

“…The absorbance was read at 405 nm. Galantamine was used as a positive control, and results were expressed in terms of IC 50 (μg/mL) [ 22 , 25 ].…”