# Antioxidant and Antibacterial Activity of Extracts from Selected Plant Material
## 3 Results and Discussion
### Phenolic Compound Profile
In addition to these two compounds, rutin and astragalin were also considered components that positively correlated with the antioxidant activity determined for the studied extracts. The aqueous ethanolic extract from _C. incanus_ was richer in flavonoids than in phenolic acids compared to the other plant extracts studied. Additionally, the ethyl acetate fraction from _C. incanus_ leaves was characterized by a higher content of flavonoids than phenolic acids, especially myricetin and quercetin derivatives [53]. Hyperoside (quercetin 3-O-galactoside) predominated in the extracts from _C. incanus_ and _B. pendula_, isoquercetin from the white mulberry and red raspberry, chlorogenic acid from _A. europaeum_ and _A. archangelica_, ellagic acid from _G. urbanum_ and rosmarinic acid from lemon balm. Rosmarinic acid is known as the main substance responsible for the healing activity of lemon balm extracts [54]. Moreover, it is commonly found in plants of the Lamiaceae family. Its content in the phenolic fractions of lemon balm was the highest when microwave-assisted extraction procedures and ethanol as solvent were used [55]. The most important constituents of hydromethanolic extracts of _C. incanus_ identified by LC-MS appeared to be myricetin and its derivatives and catechin derivatives [45]. However, HPLC analysis revealed the presence of fifteen phenolic compounds in fifteen batches of _C. incanus_ extracts, but the aqueous extracts did not contain ferulic, chlorogenic and syringic acids [47]. Gallic, ellagic and _p_-coumaric acids were found in most of the _C. incanus_ samples analyzed, and among the flavonoids isoquercetin, rutin, 7-luteolin glucoside and kaempfer were present. In the case of our study, no _p_-coumaric acid was detected in the aqueous ethanolic extracts of _C. incanus_ and the most abundant flavonoid was hyperoside (quercetin-3-O-galactoside). Using the HPLC-DAD method to identify phenolic compounds present in the aqueous infusions of the _C. incanus_ species tested, it was found that _C. incanus_ of Bulgarian origin summer and winter leaves infusions were richer in a number of polyphenols found than _C. incanus_ of Greek origin summer leaves infusion and _Melissa officinalis_ Bulgarian origin leaves and stems infusion [56]. In addition, in the Bulgarian _C. incanus_ winter leaf infusion, the concentrations of some bioactive compounds were lower than those found in the summer leaves. The same method was also used to characterize the major polyphenic compounds in a crude ethanolic leaf extract of _C. incanus_[11]. The compounds identifiedwere classified into gallic acid derivatives, condensed tannins and flavonoid glycosides. Based on UPLC-MS/MS profiling of aqueous extracts of two _Cistus_ species wild growing in Croatia, it was revealed that they were also a rich source of polyphenols with flavonoid derivatives [57]. The differences in the profile and quantity of the identified polyphenolic compounds are influenced by their chemical nature, the type and origin of the raw material, the method of extraction and the method of identification. Methanol and ethanol solvents make it possible to extract mainly polar compounds from plant material, which include polyphenols, sugars and some organic acids. Synergistic interactions can occur between these compounds, which can affect their antimicrobial and antioxidant activity. In the water extract of _Betula papyrifera_ [PERSON], nine phenolics and eleven acids were identified, while in the methanolic extracts, ten phenolic compounds and seven acids were found. Both extracts contained hydrobenzoic, caffeic and coumaric acids, but these were present in a higher proportion in the water extract [58]. In aqueous ethanolic extracts of _B. pendula_, chlorogenic acid and three flavonoids were identified instead of caffeic acid. In the birch leaf extracts from Estonia, the content of hyperoside as the principal flavonoid depended on the birch species (_B. pendula_, _B. pubesans_, _B. nana_, _B.