1260 series hplc

Optical density was determined with a Libra S11 photometer (Biochrom) at λ = 600 nm. Samples were diluted to be in the linear range of the photometer. Sucrose concentrations and corresponding monomeric glucose and fructose were determined with a photometric assay kit from r-biopharm (Art. No. 10716260035). For measuring of glucose concentration, a second method was applied using an Agilent 1260 series HPLC and a Phenomenex REZEX ROA-Organic Acid H+ (8%) column (300 mm × 7.8 mm × 8 µm) at 65 °C with a RID detector and an isocratic gradient of 0.05 mM H₂SO₄ for 45 min.

Extracts isolation was conducted by binary HPLC (high-performance liquid chromatography) pump (HPLC WATERS™ 600, Milford, MA, USA) coupled with a WATERS 996 photodiode array (PDA) UV/Vis detector and the reversed-phase semi-prep HPLC isolation condition (Phenomenex Luna 5µ C18 column, 250 mm × 10 mm, 5 µm, eluting with 40% CH₃CN at flow rate 2.0 mL/min). ESI (electrospray ionization) low-resolution LC-MS data were obtained with an Agilent Technologies 6120 quadrupole mass system (Agilent Technologies, Santa Clara, CA, USA) coupled with an Agilent Technologies 1260 series HPLC with a reversed-phase Phenomenex luna C18 column (4.6 mm × 100 mm, 5 µm) at a low flow rate of 1.0 mL/min. NMR spectra were acquired by Bruker Avance 300 MHz and 150 MHz spectrometers (Bruker Biospin Group, Karlsruhe, Germany) using methanol-d₄ as a solvent, which was purchased from Cambridge Isotope Laboratories, Inc. (Tewksbury, MA, USA). For extract fractionation, first grade solvents were acquired from Dae-Jung chemicals & Metals Co. Ltd. For LC-MS and HPLC analyses, HPLC-grade solvents were provided from J.T.Baker. and Dae-Jung chemicals & Metals Co. Ltd. (Sheung-Si, Korea).

The HPLC analysis of phenolic compounds in the samples was carried out by the modified method of Gong et al. (2021 (link)). An Agilent 1260 series HPLC coupled with a Phenomenex Luna C18 column (250 nm ◊ 4.6 mm, 5 μm, Torrance, CA, USA) was applied for the qualitative and quantitative analysis (Agilent Technologies). The binary gradient mixtures including acetonitrile (ACN) (mobile phase A) and 0.1% (v/v) phosphoric acid in water (mobile phase B) were used as the mobile phase at a flow rate of 0.8 ml/min. The column was maintained at 35°C and the injection volume was 10 μl. In this study, the superior wavelength was chosen as 330 nm. By comparing the corresponding external standard, the phenolic compounds were identified and quantified. Gradient elution was performed as given in Table S1.