SE157:/MS2

Sample Set Information

ID	TSE1313
Title	Top-down Metabolomic Approaches for Nitrogen-Containing Metabolites.
Description	Streamlining the processes that reveal heteroatom-containing metabolites and their biosynthetic genes is essential in integrated metabolomics studies. These metabolites are especially targeted for their potential pharmaceutical activities. By using a Fourier-transform ion cyclotron resonance-mass spectrometry (FTICR-MS) instrument, we provide top-down targeted metabolomic analyses using ultrahigh-resolution liquid chromatography-mass spectrometry (LC-MS), high-resolution matrix-assisted laser desorption/ionization (MALDI), and high-resolution imaging mass spectrometry (IMS) with 15N labeling of nitrogen-containing metabolites. In this study, we efficiently extract known and unknown chemicals and spatial information from the medicinal plant Catharanthus roseus, which sources several cancer drugs. The ultrahigh-resolution LC-MS analysis showed that the molecular formula of 65 N-metabolites were identified using the petals, peduncles, leaves, petioles, stems, and roots of the non- and 15N-labeled Catharanthus plants. The high resolution MALDI analysis showed the molecular formula of 64 N-metabolites using the petals, leaves, and stems of the non- and 15N-labeled Catharanthus. The chemical assignments using molecular formulas stored in databases identified known and unknown metabolites. The comparative analyses using the assigned metabolites revealed that most of the organ-specific ions are derived from unknown N-metabolites. The high-resolution IMS analysis characterized the spatial accumulation patterns of 32 N-metabolites using the buds, leaves, stems, and roots in Catharanthus. The comparative analysis using the non- and 15N-labeled IMS data showed the same spatial accumulation patterns of a non- and 15N-labeled metabolite in the organs, showing that top-down analysis can be performed even in IMS analysis.
Authors	Nakabayashi R, Hashimoto K, Toyooka K, Saito K.
Reference	Anal Chem. 2017 Mar 7;89(5):2698-2703. doi: 10.1021/acs.analchem.6b04163. Epub 2017 Feb 22.
Comment

PubMed

Analytical Method Details Information

ID	MS2
Title	MALDI
Instrument	MS FTICR–MS solariX 7.0 T (Bruker Daltonics)
Instrument Type
Ionization	ESI
Ion Mode	Positive
Description	The extract solutions of the non- and 15N-labeled Catharanthus plants (100 μL each) were evaporated and completely dried. The extracts were redissolved in 10 μL of 80% MeOH. Aliquots of the concentrated extract solutions (0.2 μL) were dispensed into 384-well plates and mixed with a CHCA matrix reagent solution [0.2 μL, 70 mg/mL 80% MeOH including 0.2% trifluoroacetic acid (TFA)]. The crystals obtained on the plate were analyzed by an FTICR–MS solariX 7.0 T (Bruker Daltonics) operated with the MALDI source. Analytical conditions were as follows: Mass range m/z 100.32–600.00; Average scan, 1; accumulation, 0.100 s; polarity, positive; Source Quench, on; resolving power, 66000 at m/z 400; transient length, 0.4893 s; mode (data storage: save reduced profile spectrum, on; reduced profile spectrum peak list, on; data reduction, 95%; auto calibration: online calibration, on; mode, single; threshold (abs), 1 × 105; mass tolerance, 50 ppm; reference mass m/z 337.191054); API Source (API source: source, ESI; capillary, 4500 V, end plate offset, −500; source gas tune: nebulizer, 1.0 bar; dry gas, 2.0 L/min; dry temperature, 180 °C); ion transfer (Source Optics: capillary exit, 220 V; detector plate, 200 V; funnel 1, 150 V; skimmer 1, 55 V; funnel RF amplitude, 200 Vpp; octopole: frequency, 5 MHz; RF amplitude, 500 Vpp; quadrupole: Q1Mass, m/z 100; collision cell: collision voltage, −2.0 V; DC extract bias, 0.0 V; RF frequency, 2 MHz; collision RF amplitude, 1500.0 Vpp; transfer optics: time of flight, 1800 ms; frequency, 2 MHz; RF amplitude, 400.0 Vpp); analyzer (infinity cell: transfer exit lens, −20.0 V; analyzer entrance, −10.0 V; side kick, 8.0 V; side kick offset, −1.5 V; front trap plate, 0.500 V; back trap plate, 0.450 V; sweep excitation power, 12.0%; multiple cell accumulations: ICR cell fills).
Comment_of_details