A new myricetin-rhamnodiglucoside from Camellia sinensis

Abstract

The isolation and structural elucidation of the novel myricetin-3-O-[β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 6)-β-D-glucopyranoside] from tea (Camellia sinensis (L.) O. Kuntze) by means of HPLC-MS/MS and various NMR techniques is described. The compound was not present in all tea samples analysed. In the case of white tea, it was detected in 20 out of 40 samples analysed (35–255 mg kg⁻¹), in green tea it was detected in 18 out of 35 samples in the same concentration range (37–205 mg kg⁻¹), while it was found only in 1 sample (51 mg kg⁻¹) of 5 black teas analysed.

Keywords:

• Camellia sinensis Theaceae
• white tea
• flavonol glycosides
• myricetin-rhamnodiglucoside
• HPLC-PDA
• HPLC-ESI-MS/MS
• 1D/2D NMR

Acknowledgements

The authors would like to thank Dr K. Ibrom (Institute of Organic Chemistry, Technische Universität Braunschweig, Germany) for providing the NMR measurements and Dr G. Jerz (Institute of Food Chemistry, Technische Universität Braunschweig, Germany) for helping with the NMR analysis. The authors are grateful to Dr V. Wray (Centre of Infection Research, Braunschweig, Germany) for valuable discussions and comments on the manuscript.