Although these fractions appeared as single peaks in their chromatograms, the 1H NMR spectra indicated that they were not pure compounds. The two fractions were subjected to an LC-MSTOF experiment to determine the molecular weight of the apparent mixture. Both fractions appeared as single peaks in the HPLC chromatogram
and gave m/z values (negative ESI) of 1185.3568 (tR = 4.40 min) and 1185.3470 (tR = 4.70 min). These molecular weights indicate identical molecular formulas (M − 1) of C52H65O33