In the urine of a Niemann–Pick disease type C (NPC) patient, we have identified three characteristic intense peaks that have not been observed in the urine of a 3β-hydroxysteroid-Δ5-C27-steroid dehydrogenase deficiency patient or a healthy infant and adult. Based on accurate masses of the protonated molecules, we focused on two of them as candidate NPC diagnostic markers. Two synthesized authentic preparations agreed with the two compounds found in NPC patient urine in regard to both chromatographic behavior and accurate masses of the deprotonated molecules. Moreover, the isotopic patterns of the deprotonated molecules, twin peaks unique to the sulfur-containing compounds appearing in their second isotope positions, and accurate masses of product ions observed at m/z 97 also agreed between the target compounds and authentic preparations. We identified the two compounds as the sulfated cholesterol metabolites as 3β-sulfooxy-7β-hydroxy-5-cholen-24-oic acid and 3β-sulfooxy-7-oxo-5-cholen-24-oic acid. These two compounds represent more promising candidate diagnostic markers for NPC diagnosis than three other candidates that are multiple conjugates of cholesterol metabolites, 3β-sulfooxy-7β-N-acetylglucosaminyl-5-cholen-24-oic acid and its glycine and taurine conjugates, although we have reported an analytical method for determining the urinary levels of these compounds using liquid chromatography/electrospray ionization tandem mass spectrometry, because of their lack of N-acetylglucosamine conjugation.
2017 MSSJ Award for Excellent Paper
Mass spectrometry imaging (MSI) with ambient sampling and ionization can rapidly and easily capture the distribution of chemical components in a solid sample. Because the spatial resolution of MSI is limited by the size of the sampling area, reducing sampling size is an important goal for high resolution MSI. Here, we report the first use of a nanopipette for sampling and ionization by tapping-mode scanning probe electrospray ionization (t-SPESI). The spot size of the sampling area of a dye molecular film on a glass substrate was decreased to 6 μm on average by using a nanopipette. On the other hand, ionization efficiency increased with decreasing solvent flow rate. Our results indicate the compatibility between a reduced sampling area and the ionization efficiency using a nanopipette. MSI of micropatterns of ink on a glass and a polymer substrate were also demonstrated.
2017 MSSJ Award for Excellent Paper
2017 MSSJ Award for Excellent Paper
Technical Challenges in Mass Spectrometry-Based Metabolomics
Released: November 25, 2016 | Volume 5 Issue 2 Pages S0052
Fumio Matsuda
pH Dependence of the Number of Discrete Conformers of Carbonic Anhydrase 2, as Evaluated from Collision Cross-Section Using Ion Mobility Coupled with Electrospray Ionization
Released: March 01, 2018 | Volume 7 Issue 1 Pages A0064
Yoshiaki Nabuchi, Kenji Hirose, Mitsuo Takayama
A Brief Review of Bioinformatics Tools for Glycosylation Analysis by Mass Spectrometry
Released: February 24, 2017 | Volume 6 Issue 2 Pages S0064
Pei-Lun Tsai, Sung-Fang Chen
Improving the Resolution of Kendrick Mass Defect Analysis for Polymer Ions with Fractional Base Units
Released: March 28, 2017 | Volume 6 Issue 1 Pages A0055
Thierry Fouquet, Hiroaki Sato
A Method for Simultaneous Determination of 25-Hydroxyvitamin D3 and Its 3-Sulfate in Newborn Plasma by LC/ESI-MS/MS after Derivatization with a Proton-Affinitive Cookson-Type Reagent
Released: August 31, 2016 | Volume 5 Issue 2 Pages S0051
Tatsuya Higashi, Mai Yokota, Ayaka Goto, Kenji Komatsu, Takahiro Sugiura, Shoujiro Ogawa, Mamoru Satoh, Fumio Nomura