Isolute spe cartridges

Cell culture media and reagents were obtained from Life Technologies, Sigma-Aldrich (Poole, Dorset, UK), LGC (Teddington, Middlesex, UK), and GE Healthcare, Little Chalfont, Buckinghamshire, UK. All other materials were sourced as indicated below. Unless otherwise stated, reagents and solvents for chemical synthesis were readily available from commercial suppliers.
Analytical LC-MS was performed using a Waters ZQ instrument and purity assessed using a diode array detector. Chromatography was performed using a Phenomenex Gemini 5.0 × 3.0 mm, 5 µm, C₁₈ column with a flow rate 1 mL/min using solvents A and solvent B according to the following gradient: Solvents: A: 0.1% v/v formic acid/water; B: 0.1% v/v form ic acid/MeCN; % B: ramping from 5% B to 95% B between 0 min and 3.5 min and then continuing at 95% B for 3.5–5 min.
Compounds were typically purified by standard flash column chromatography using BDH silica gel, purchased from VWR, or using a Flash Master Personal with Isolute SPE cartridges, purchased from Biotage. Where necessary, reversed phase preparative LC-MS was performed using the Waters ZQ instrument. The structures and purities of compounds were assigned using analytical LC-MS and ¹H NMR. ¹H NMR spectra were run on a Bruker 400 MHz instrument and spectra were analysed using MestReC. Chemical shifts are given in ppm and coupling constants (J) are quoted in Hz.

Solvents used for the sample preparation and HPLC-FLD analysis were all HPLC-grade, while solvents used for the HPLC-HRMS analysis were MS-grade. Acetonitrile (ACN), ammonium formate, formic acid, ethyl acetate, MeOH, and trifluoroacetic acid were all purchased from Sigma-Aldrich (Schnelldorf, Germany), while 2-BuOH was purchased from Fisher Scientific (Waltham, MA, USA). Water was purified by reverse osmosis and a subsequent MilliQ-system (Millipore, Bedford, MA, USA). Fluorescence derivatization was achieved using AccQ-Fluor reagent WAT052880 (Waters, Milford, MA, USA). External calibration was carried out using a fumonisin B₁ (49.9 µg/mL) and fumonisin B₂ (50.6 µg/mL) mixture in H₂O:ACN (1:1, v/v), purchased from Romer Labs (Tulln, Austria). Four different Isolute SPE cartridges (C18 (MFC) (3 mL, 500 mg), C8 (3 mL, 500 mg), C2 (3 mL, 500 mg) and Isolute Myco (3 mL, 60 mg)) were purchased from Biotage (Uppsala, Sweden), while Strata-X (3 mL, 30 mg) SPE cartridges were purchased from Phenomenex (Torrance, CA, USA).