SE48:/MS01

Sample Set Information

ID	SE48
Title	Toward better annotation in plant metabolomics: isolation and structure elucidation of 36 specialized metabolites from Oryza sativa (rice) by using MS/MS and NMR analyses
Description	We isolated and elucidated the structures of specialized metabolites from rice by using MS/MS and NMR. Thirty-six compounds, including five new flavonoids and eight rare flavonolignan isomers, were isolated from the rice leaves. The MS/MS spectral data of the isolated compounds, with a detailed interpretation of MS fragmentation data, will facilitate metabolite annotation of the related phytochemicals by enriching the public mass spectral data depositories, including the plant-specific MS/MS-based database, ReSpect.
Authors	Zhigang Yang, Ryo Nakabayashi, Yozo Okazaki, Tetsuya Mori, Satoshi Takamatsu, Susumu Kitanaka, Jun Kikuchi, Kazuki Saito
Reference	Yang Z et al. (2014) Metabolomics 10: 543-555
Comment

The original paper is available at Metabolomics.

The raw data files are available at DROP Met web site in PRIMe database of RIKEN.

Analytical Method Details Information

ID	MS01
Title	LC–QTOF-MS/MS analysis
Instrument	Waters ACQUITY UPLC System and Waters Xevo G2 QTOF mass spectrometer
Instrument Type	UPLC-QTOF-MS
Ionization	ESI
Ion Mode	Positive and negative
Description	Isolation of specialized metabolites The leaf powder of rice (90 g) was extracted with 90 % methanol as described in a previous study (Matsuda et al. 2012). The extract was dissolved, suspended in water, and partitioned into a hexane and water layer. The water layer was subjected to ODS column chromatography and eluted with CH3OH–H2O (0:100 → 100:0 v/v; containing 0.05 % formic acid) to afford nine fractions (Fr.1–9). These fractions were purified using semipreparative HPLC performed under the following conditions: column, Cadenza CD-C18 or Unison UK-C18 columns, Imtakt 150 9 10 mm i.d.; particle size, 3 lm; solvents, water and methanol or acetonitrile, containing 0.1 %v/v formic acid; and flowrate, 3.0 mL/min. The following compounds were obtained: 1 (4.52 mg), 2 (12.69 mg), 3 (2.07 mg), 4 (2.57 mg), 5 (1.15 mg), 6 (0.94 mg), 7 (1.51 mg), 8 (1.23 mg), 9 (0.71 mg), 10(2.53 mg), 11 (1.63 mg), 12 (3.93 mg), 13 (2.74 mg), 14 (0.58 mg), 15 (0.96 mg), 16 (1.89 mg), 17 (0.22 mg), 18 (0.09 mg), 19 (0.65 mg), 20 (0.20 mg), 21 (0.28 mg), 22 (0.64 mg), 23 (1.04 mg), 24 (0.76 mg), 25 (2.31 mg), 26 (2.20 mg), 27 (2.04 mg), 28 (1.25 mg), 29 (0.64 mg), 30 (0.29 mg), 31 (0.63 mg), 32 (2.29 mg), 33 (4.84 mg), 34 (4.99 mg), 35 (1.13 mg), and 36 (2.70 mg). For details regarding the isolation procedures from rice, see Supplementary data file S1. LC–quadrupole time-of-flight-tandem mass spectrometry (LC–QTOF-MS/MS) analysis LC analysis was performed on the Waters ACQUITY UPLCTM System. Samples were injected into an ACQUITY bridged ethyl hybrid (BEH) C18 column (100× 2.1 mm i.d.,1.7μm;Waters,Milford, MA, USA),and the column temperature was set at 40 ℃.The mobile phase consisted of A (0.1 % v/v formic acid in water) and B (0.1 % v/v formic acid in acetonitrile). The gradient　conditions of the mobile phase were as follows: 0 min,99.5 % A; 10.0 min, 20 % A; 10.01 min, 0.5 % A;12.0 min, 0.5 % A; 12.1 min, 99.5 % A; and 14.5 min, 99.5 % A. The flow rate was 0.30 mL/min. UV–visible absorption spectra of samples were determined using a photodiode array (PDA) detector in the range of 200–600 nm. The sample injection volume was 1μL. MS detection was performed on a Waters Xevo G2 QTOF mass spectrometer with an electrospray ionization (ESI) interface (Waters). Full scan mass spectra were recorded through a range of 50–1,500 m/z. Nitrogen was used as the nebulizer and auxiliary gas; argon was utilized as the collision gas. The ESI source was operated in positive and negative ionization modes with a capillary voltage of 3 kV, sampling cone voltage of 25 V, cone gas flow of 50 L/h, desolvation gas flow of 800 L/h, desolvation temperature of 450 ℃, source temperature of 120 ℃, and CID energy ramped from 10 to 50 eV. Tandem MS analysis was performed using fast data directed analysis (FastDDA), which is rapid automated, intelligent MS/MS data acquisition for targeted qualitative analyses.
Comment_of_details