M2998

The high-performance liquid chromatography (HPLC) method was used for a detailed investigation of changes in the lyophilized water extracts obtained from the leaves of black currant. The analysis was performed using an Empower-Pro chromatograph (Waters), equipped with a quaternary pump (M2998 Waters) with a degasser and a UV–VIS diode array detection system. Separation was performed on a column filled with modified silica gel RP-18 (Atlantis T3, Waters; 3 µm, 4.6 × 150 mm). The mobile phase consisted of A (1% acetic acid) and B (acetonitrile), in which the concentration of solvent B changed as follows: until 0–8th min, 8–12%; in the 10th min, 20%; and in the 25th min, 25%; the flow speed was set at 1 mL min⁻¹. Detection was carried out at 330 nm. The identified compounds (marked by peak numbers on the chromatogram) were quantified according to the calibration curves prepared for each compound, and their content was expressed as mg/g dry extract.

The HPLC analysis was performed on a liquid chromatograph with a DAD detector (M2998), operated by the Empower-Pro software (Waters). The separation was carried out on an RP-18 column (Luna 3 µm, 4.6 mm x 150mm) in the following gradient system: A—100% ACN, B—redistilled water, C—100% MeOH: 0–15 min, 18–22% AC, 15–27 min, 22–25% AC, 27–35 min, 25–30% AC, 35–45 min, and 30–50% AC. The flow rate was 1 mL/min, and the sample volume dispensed was 20 µl. Detection of the obtained chromatographic separations was carried out at two wavelengths—λ = 280 nm and λ = 330 nm.

The HPLC method was used for detailed investigations of the chemical profile of the extracts from the infested and uninfested leaves. The analysis was performed using an Empower-Pro chromatograph (Waters), which consists of a quaternary pump (M2998 Waters) with a degasser and a UV-Vis diode array detection (DAD) system. Separation was performed on a column filled with modified silica gel RP-18 (Atlantis T3—Waters, 3 μm, 4.6 mm × 150 mm). The mobile phase consisted of A (1% acetic acid in water) and B (acetonitrile). The program of the gradient elution was set as follows: 20% B (0 to 10 min); 20–25% B (10 to 25 min); 25–45% B (25 to 40 min); the flow speed was 1 mL/min. The qualitative analysis of phenolic compounds was performed on the basis of retention times and diode array spectral characteristics in comparison with available standards of phenolic compounds. In addition, quantitative investigations were performed on the basis of the areas of the peaks of the tested compounds and calibration curves prepared separately for each standard compound. The DAD detection was conducted at 280 nm for phenolic acid derivatives and at 330 nm for flavonoid derivatives for the purpose of quantitative analysis. The content of phenolic derivatives was expressed as mg/g of dry matter.