Mass spectrometry data of metabolomics analysis of Nepenthes pitchers

Hybridisation plays a significant role in the evolution and diversification of plants. Hybridisation among Nepenthes species is extensive, either naturally or man-made. To investigate the effects of hybridisation on the chemical compositions, we carried out metabolomics study on pitcher tissue of Nepenthes ampullaria, Nepenthes rafflesiana and their hybrid, Nepenthes × hookeriana. Pitcher samples were harvested and extracted in methanol:chloroform:water via sonication-assisted extraction before analysed using LC-TOF-MS. MS data were analysed using XCMS online version 2.2.5. This is the first MS data report towards the profiling, identification and comprehensive comparison of metabolites present in Nepenthes species.


a b s t r a c t
Hybridisation plays a significant role in the evolution and diversification of plants. Hybridisation among Nepenthes species is extensive, either naturally or man-made. To investigate the effects of hybridisation on the chemical compositions, we carried out metabolomics study on pitcher tissue of Nepenthes ampullaria, Nepenthes rafflesiana and their hybrid, Nepenthes × hookeriana. Pitcher samples were harvested and extracted in methanol: chloroform:water via sonication-assisted extraction before analysed using LC-TOF-MS. MS data were analysed using XCMS online version 2.2.5. This is the first MS data report towards the profiling, identification and comprehensive comparison of metabolites present in Nepenthes species. &

Data
This dataset comprises the acquired MS raw data (mzXML files), and analysed data in MS Excel (.xlsx) file (Supplementary Table 1) generated from XCMS online analysis of MS data from pitcher extracts of N. ampullaria, N. rafflesiana and their hybrid N. × hookeriana.

Samples collection
Three lowland Nepenthes species, N. ampullaria, N. rafflesiana and N. × hookeriana were sampled from the experimental terrace of Universiti Kebangsaan Malaysia (2°55'12.7"N, 101°46'59.7"E). Pitcher tissues were harvested 7 days after pitcher opening when the pitchers achieved fully functionality [4]. The pitcher fluids were emptied and rinsed with sterile deionised water before immediately frozen in liquid nitrogen and stored at −80°C.

Phytochemical extraction
Each sample was crushed and ground until fine powder before lyophilised for 48 h. Extraction from the dried powder was performed according to [5] with slight modifications. Dried powder samples (10 mg) were extracted with 200 µL of methanol:chloroform:water (3:1:1). Samples were vortexed, sonicated at room temperature for 15 min, vortexed again and then centrifuged at 10,000g for 10 min. Filtered extracts through a 0.22 µm PTFE membrane were stored at −80°C.
High resolution MS was carried out using a MicrOTOF-Q III (Bruker Daltonic) using an ESI positive ionisation with the following settings: capillary voltage at 4500 V, nebuliser pressure at 1.2 bar and drying gas flow at 8 L/min with the source temperature at 200°C and m/z range from 50 to 1000 Da.

Mass spectrometry data handling
The acquired MS raw data were converted to the mzXML file format by Bruker Compass DataAna-lysisViewer version 4.2. The converted data were processed by XCMS online software package [6] with Arabidopsis thaliana selected as the bio-source and other default settings to carry out feature detection, peak alignment, retention time correction, statistical analysis, annotation and identification.