Isolation and identification of spermidine derivatives in tea (Camellia sinensis) flowers and their distribution in floral organs.

Background: Recently, tea (Camellia sinensis) flowers have attracted increasing interest because of their content of bioactive compounds such as catechins. The aim of this study was to investigate the occurrence of some characteristic compounds in tea flowers.

Results: A principal component analysis of metabolites using ultra-performance liquid chromatography/time-of-flight mass spectrometry showed differences in metabolite profile between flowers and leaves of C. sinensis var. Yabukita. Four spermidine derivatives were isolated from tea flowers. One of them was determined as N(1) ,N(5) ,N(10) -tricoumaroyl spermidine based on NMR, MS and UV data. The other three were identified as feruoyl dicoumaroyl spermidine, coumaroyl diferuoyl spermidine and triferuoyl spermidine based on MS(n) data. Tricoumaroyl spermidine as the major spermidine conjugate was not detected in tea leaves. Furthermore, it decreased during floral development and mainly occurred in anthers.

Conclusion: This study has provided the first evidence that spermidine-phenolic acid conjugates occur in tea flowers in considerable amounts. Their presence should prompt a reconsideration of the ecological role of tea flowers. From an economic point of view, tea flowers might be suitable as a raw material in the healthcare food and pharmaceutical industries.