Abstract: Structure and function of polypehnols with high molecular weights
(tannins) were briefly reviewed to better understand the significance of
polyphenol-rich foods and beverages. In a survey of bioactive ellagiannins with
a macrocyclic structure and/or a gluconic acid core, some new oligomeric
ellagitannins (eucarpanins and elaeagnatins) have been found in species of
Myrtaceae and Elaeagnaceae, and their structures were elucidated by
spectroscopic and chemical methods. Cytotoxic activity against human oral tumor
cell lines and antibacterial activity against {\it Helicobacter pylori} have
been evaluated for the ellagitannins obtained from both plants, and related
compounds. The macrocyclic dimers, oentothein B, camelliin B and woodfordin C
showed a remarkable cytotoxicity against human oral squamous cell carcinoma,
but not against normal cells. These active tannins induced apoptosis of tumor
cells. A potent antibacterial activity against {\it Helicobacter pylori} was
exhibited by monomeric ellagitannins such as tellimagrandin I and
stricitinin.
Keywords: tannins, macrocyclic ellagitannin oligomers, ellagitannin with gluconic acid core, anti-{\it Helicobacter pylori} activity, cytotoxicity against human oral tumor cells
Journal: BioFactors, vol. 13, no. 1-4, pp. 121-125, 2000
