Direct injection-electron ionization-mass spectrometry and NMR metabolomics method for analyzing Rhubarb species that inhibit adult T-cell leukemia proliferation

Metabolic profiling techniques are commonly used to find possible correlations between the metabolic profile of a compound and its biological activity. Direct Injection-Electron Ionization-Mass Spectrometry (DI-EI-MS) [1] and NMR are comprehensive and powerful tools for such analyses, because they allow the simultaneous detection of diverse groups in both primary and secondary metabolites. We were able to select blueberry species whose leaves have anti-proliferative effect in adult T-cell leukemia (ATL) cells, by DI-EI-MS- and NMR-based metabolomic techniques [2]. It is well known that Rhubarb species have also anti-proliferative effect in several cancer cells. However, the active constituents in Rhubarb species are not fully identified. In the present study, we assessed if constituents in Rhubarb species have anti-proliferative effect in ATL cells. Furthermore, we also tried to distinguish the Rhubarb species having better anti-proliferative effect in ATL cells from the other Rhubarb species. Methanol extracts from roots or leaves of some Rhubarb species showed anti-proliferative effect in ATL cells. Therefore, DI-EI-MS- and NMR-based metabolomics can be used to classify bioactive extracts. Principal component analysis of the extracts interpreted from the loading plot analysis showed that each extract had unique ion peaks or chemical shifts. This unique information observed in Rhubarb species were associated with high anti-proliferative effect in ATL cells. These results suggest that Rhubarb species could be classified based on the results of metabolite profiling with DI-EI-MS and NMR.

• References

• 1 Kai H, Kinoshita K, Harada H, Uesawa Y, Maeda A, Suzuki R. et al. Establishment of a direct-injection electron ionization-mass spectrometry metabolomics method and its application to Lichen profiling. Anal Chem 2017; 89: 6408-6414
• 2 Kai H, Uesawa Y, Kunitake H, Morishita K, Okada Y, Matsuno K. Direct-injection electron ionization-mass spectrometry metabolomics method for analyzing blueberry leaf metabolites that inhibit adult T-cell leukemia proliferation. Planta Med 2019; 85: 81-87