The Applicability of MALDI-MS to High-throughput Metabolic Profling of Diverse Green Tea Extracts with Antioxidant Activity

摘要

Background: Metabolic profiling can provide information on the relationship between the metabolome (global low-molecular weight-compound profiles) and bioactivity. Here, we performed metabolomic analyses to explore the relationship between the metabolome and antioxidant activity of diverse Japanese green tea cultivars (Camellia sinensis L.). Method/Result: We investigated the ability of hot water extracts from 19 cultivars of Japanese green tea leaves to exhibit the oxygen radical absorbance capacity (ORAC), one of the simple antioxidant assays. Among the tested cultivars, Syunmei showed the highest ORAC. Ranking of Yabukita, the most commonly consumed cultivar in Japan, was 15th. To evaluate the bioactivity of green tea cultivars using a metabolomics approach, metabolite profiles of all tea extracts were determined by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS). Multivariate analyses revealed differences among green tea cultivars with respect to their ORAC. In Syunmei cultivar, polyphenols were associated with is metabolic profile and bioactivity. In addition, using partial least-squares regressio analysis, we succeeded in contructing a reliable bioactivity-predictio model to predict the ORAC of tea cultivars based on their metabolome.