## 2 Materials and Methods
### Phytochemical Research  
Flavonoids and hydroxycinnamic acids (caffeic and chlorogenic acids) were identified using TLC. Chromatographic analysis was carried out using a solvent system consisting of glacial acetic acid R: water R: ethyl acetate R (20: 20: 60). Two reagents were used to detect components on the chromatographic plate: the first was a solution of aminoethyl ester of diphenylboronic acid R with a concentration of 10 g/L in methanol R, which promotes the fluorescence of certain compounds and the second was a solution of macrogl 400 R with a concentration of 50 g/L in methanol R, which was used to enhance the signal. Identification of substances was carried out under ultraviolet light with a wavelength of 365 nm using a special UV lamp, which allowed for clear visualisation of chromatographic zones and determination of the presence of target compounds.  
Flavonoid content was analysed using high-performance liquid chromatography (HPLC) on an Agilent Technologies 1200 system (Santa Clara, CA, USA). The mobile phase consisted of acetonitrile (solvent A) and 0.1% aqueous formic acid (solvent B), applied in a gradient mode: 0 min--30% A/70% B; 20 min--70% A/30% B; 22 min--100% A; 30 min--100% A. Separation was performed on a Zorbax SB-C18 column (3.5 \(\mu\)m, 150 \(\times\) 4.6 mm; Agilent Technologies, Santa Clara, CA, USA) at a flow rate of 0.25 mL/min. The injection volume was 100 \(\mu\)L and the column temperature was maintained at 25 \({}^{\circ}\)C. Detection was carried out using a diode-array detector (DAD) at 280 and 365 nm, with spectral data collected in the 210-270 nm range [20; 21].  
Hydroxcinnamic acids were examined using the same HPLC system. Methanol (A) and 0.1% formic acid in water (B) served as the mobile phase, with gradient elution as follows: 0 min--25% A/75% B; 25 min--75% A/25% B; 27 min--100% A; 35 min--100% A. The separation was carried out on a Zorbax SB-Aq column (4.6 mm \(\times\) 150 mm, 3.5 \(\upmu\)m; Agilent Technologies, Santa Clara, CA, USA) at a flow rate of 0.5 mL/min, with the column maintained at 30 \({}^{\circ}\)C and an injection volume of 4 \(\upmu\)L. Detection was performed at 250 and 275 nm, with absorption spectra recorded between 210 and 270 nm [22].  
Tannin-related compounds were also analysed using the Agilent 1200 HPLC system. The mobile phase consisted of methanol (A) and 0.1% aqueous formic acid (B), with the following gradient: 0 min--20% A/80% B; 25 min--75% A/25% B; 27 min--100% A; 35 min--100% A. Separation was conducted on a Zorbax SB-C18 column (3.5 \(\upmu\)m, 150 \(\times\) 4.6 mm) at a flow rate of 0.25 mL/min, with the column temperature set to 35 \({}^{\circ}\)C and an injection volume of 4 \(\upmu\)L. Detection was carried out at 250 and 275 nm, with spectra recorded in the 210-270 nm range [23].  
The identification and quantification of compounds were performed by comparing retention times and UV spectra with those of certified reference standards, including quinic, gallic, benzoic, syringic, caffeic, \(p\)-coumaric, \(trans\)-ferulic, sinapic, and \(trans\)-cinnamic acids, as well as rutin, quercetin-3-glucose, naringin, neohesperidin, quercetin, luteolin, apigenin, naringenin, pyrocatechin, epicatechin gallate, and gallocatechin (Sant Louis, MI, USA). All measurements were performed in triplicate for statistical reliability.  
The content of total phenolic compounds in the extracts was quantified using a spectrophotometric method in accordance with the State Pharmacopoea of Ukraine, edition 2.0, with results expressed in pyrogallol equivalents [24]. Total flavonoid concentration was determined spectrophotometrically following the same pharmacopoeial guidelines, with rutin used as the reference standard [16; 24]. All analyses were performed in triplicate to ensure statistical reliability.