## 3 Results and Discussion
### Total Phenols Content (TPC) of Medicinal Plant Extracts
The maximum content was recorded in the case of extraction with ethyl acetate (143.5 mg GAE/g) and the lowest in the case of extraction with methylene chloride (41.6 mg GAE/g). Other studies reported a TPC content of 15.05 mg GAE/g in ethanolic TV extract [38], respectively 10.7-12.63 mg GAE/g in the methanolic extract determined by [PERSON] et al. [45] or 15.06 mg GAE/g for the methanolic extracts of thyme flowers reported by [PERSON] et al. [46]. In HP extract, the TPC was reported in the concentration of 77.72 \(\pm\) 1.83 mg GAE/g plant material and TFC 1.30 \(\pm\) 0.10 mg GAE/g [47], while in MP 70.06 mg GAE/g and SO 50.89 mg GAE/g was detected [48]. The TPC for the CS samples extracted with MWE (Figure 2e) is maximum in the plant extracts from the Lamiaceae family: SO1 (33.24 mgGAE/g DM), MP (31.65 mgGAE/g DM), MO (30.68 mgGAE/g DM), TS (27.85 mgGAE/g DM), and minimum in the case of HO (15.60 mgGAE/g DM), HP (19.92 mgGAE/g DM), and EP (19.38 mgGAE/g DM). TPC in FG extracted by MWE was maximum in the cases of AM (51.04 mgGAE/g DM), HP(49.86 mgGAE/g DM), and EP (45.14 mgGAE/g DM) and minimum in the case of OV (15.03 mgGAE/g DM). Maximum differences between the content of TPC extracted by MWE in CS and FG forms were recorded in the cases of AM (30.42 mgGAE/g DM), HP (29.95 mgGAE/g DM), and EP (25.75 mgGAE/g DM). The differences between the TPC (%) of the crushed microwave-extracted samples and powder are maximum in the case of HP extract (60.06%), followed by AM (59.59%) and EP (57.06%). Minimal percentage differences were recorded in the cases of OV extract (2.57%) and SO (5.62%). The increase in TPC content (%) using MWE from the sample processed in powder form (FG) compared to the crushed sample (CS) (Figure 2f) was maximum in HP extract (150.35%), followed by the 2 medicinal plants from the Asteraceae family: HP (147.47%) and EP (132.86%). Figure 3 shows the TPC values compared for the three procedures used. It can be observed that MWE ensures the highest extraction of TPC from medicinal plant samples for most of the analyzed samples, except for HP and OV extracts, for which UAE represented the process that led to the highest TPC content, both in the crushed or powdered form of the sample. The preparation of plant material in powder form (FG) increases the ultrasound process's efficiency in the case of SO and MO extracts. Significant differences (\(p<0.05\)) from a statistical point of view were recorded between the 3 procedures for the majority of the analyzed plants, prepared in coarse shredding (CS) form. The exceptions were the pairs UAE/MWE in HO and LA extract and the pairs CES/UAE for SO2 extract. Regarding the FG form, no significant differences (\(p<0.05\)) were obtained between CES and MWE for SO1 and EP and between the pairs UAE and MWE for SO2, LA, and CO. The classic extraction with solvent (CES) proved to be the procedure with the lowest yield regarding TPC, especially in the case of processing plants in a shredded form (CS). When using the plant material as powder (FG), the conventional extraction method showed efficiency comparable to the other extraction methods and a slightly higher yield in the case of AM, HO, and CO extracts. [PERSON] et al. compared the efficiency of UAE and Soxhlet extraction procedures for 9 medicinal plants from Norway, highlighting the advantage of using UAE compared to the Soxhlet method [49]. On the contrary, another study reported that the extract obtained from EP using the classical solvent extraction contained a higher amount of total phenols and flavonoids than the ultrasound extract [50]. The TPC using classical extraction was 60.2 mg/g and 46.8 mg/g when ultrasound extraction was performed. Figure 3: The TPC compared for the 3 extraction methods (**a**) CS, (**b**) FG. According to the \(t-\)test, the different lower-case letters (a–c) represent the significant differences (\(p<0.05\)) between samples from the same plant obtained by different extraction methods.