Hydrolyzable tannins with the hexahydroxydiphenoyl unit and the m-depsidic link: HPLC-DAD-MS identification and model synthesis     

Arapitsas P  Menichetti S  Vincieri FF  Romani A 《Journal of agricultural and food chemistry》2007,55(1):48-55

This study was designed to develop efficient analytical tools for the difficult HPLC-DAD-MS identification of hydrolyzable tannins in natural tissue extracts. Throughout the study of the spectroscopic characteristics of properly synthesized stereodefined standards, it was observed that the UV-vis spectra of compounds with the m-depsidic link showed a characteristic shoulder at 300 nm, consistent with the simple glucogalloyl esters, whereas compounds with the hexahydroxydiphenoyl (HHDP) unit gave a diagnostic fragmentation pattern, caused by a spontaneous lactonization in the mass spectrometer. These observations were confirmed by HPLC-DAD-MS analyses of tannic acid and raspberry extracts, which are rich in hydrolyzable tannins with the m-depsidic link and the HHDP unit, respectively.  相似文献