Fig. 4. ESI-MS spectra of NPC patient urine at 17.99 min (A); the authentic preparation of 3β-sulfooxy-7β-hydroxy-5-cholen-24-oic acid (B); NPC patient urine at 20.12 min (C); and authentic preparation of 3β-sulfooxy-7-oxo-5-cholen-24-oic acid (D), respectively.
Theoretical accurate masses of m/z 469, 470, and 471 produced from C24H38O7S are shown in the inserted list in (A, B), and those of m/z 467, 468, and 469 produced from C24H36O7S are shown in the inserted list in (C, D). The inserted spectra show twin peaks at each second isotopic position with accurate masses and abundances. Chromatographic and mass spectrometric conditions are shown in Experimental section.
