Accumulation pattern of catechins and flavonol glycosides in different varieties and cultivars of tea plant in China

Abstract

Flavonoids are important phenolic compounds in tea plant since they have a large number of physiological functions for plants themselves and human beings. Tea samples (n = 151) harvested from 3 varieties, 9 plantation areas and 107 cultivars were analyzed to describe the attributes of catechins and flavonol glycosides in China. A support vector machine (SVM) classifier was built to recognize the assamica variety with 94.2 % accuracy. Accumulation of (-)-epicatechin gallate (ECG) and flavonol di-glycosides was especially observed in assamica variety, while (-)-epigallocatechin gallate (EGCG) and flavonol tri-glycosides were obviously accumulated in sinensis variety. The ratios of ECG/EGCG and flavonol tri-glycosides/flavonol di-glycosides could be used as indicators for distinguishing the different varieties and cultivars. Accumulation pattern of catechins and flavonol glycosides were mainly dependent on the genetic background of the cultivars rather than plantation locations. The increased hydroxyl groups at the C-ring of catechins and the extended sugar chain at the B-ring of flavonol glycosides could be considered as important rules of metabolite change during tea plant evolution. The mechanism of accumulation of flavonoids in various varieties and cultivars was also discussed.