Hplc 1200 device

HPLC analysis was performed using a HPLC 1200 device (1200 series, Agilent, USA) (Raza et al., 2009 (link)). For the detection of LPs, a 20 μL sample pretreated using an XAD-16 column was injected into the HPLC column (Eclipse XDB-C18, 4.6 × 250 mm, 5 μm, Agilent). The purification was performed using a solvent containing A [0.1% (v v⁻¹) CH₃COOH] and B (CH₃CN) at a flow rate of 0.6 mL min⁻¹. An ultraviolet (UV) detector was used to detect peaks at 210 nm. The elution conditions were as follows: from 0 to 9 min, 60 to 93% (v v⁻¹) mobile phase A plus 40–7% (v v⁻¹) mobile phase B; from 9 to 20 min, 93% solvent B and 7% solvent A. The temperature was maintained at 35°C. Three replicates were detected out of each biological replicates. After HPLC detection, the peak area of each tested active compounds was analyzed.

HPLC was performed using a HPLC 1200 device (1200 series, Agilent, Santa Clara, CA, USA) to analyze macrolactins. For analysis, a 5 μL sample was injected into the HPLC column (Eclipse XDB-C18, 4.6 mm × 250 mm, 5 μm, Agilent, Santa Clara, CA, USA). The conditions were set up as described in our previous study (Yuan et al., 2012a (link)). Briefly, the column temperature was maintained at 20°C throughout the analysis; the mobile phase was the solvent containing 60% A (0.1% (v/v) CH₃COOH) and 40% B (CH₃CN) at a flow rate of 0.6 mL/min; and an ultraviolet (UV) detector was used to detect peaks at 230 nm. There is no commercial standard sample for sale. The standard sample was obtained using high-speed counter-current chromatography (HSCCC) method reported previously (He et al., 2012 (link), 2013 (link)). The concentration of macrolactins in the collected solution was quantified to be 38.6 mg/L.