Tannins are distributed in several plant species, organs and tissues, where they play a role in inhibiting microbial decay, thus enhancing material durability. In the hydrolysable tannins (HTs), a carbohydrate molecule (usually D-glucose) is partially or totally esterified with phenolic groups , such as gallic or ellagic acids (gallotannins, GTs; or ellagitannins, ETs). HTs are hydrolyzed by weak acids or bases, and are more easily oxidized than condensed tannins (CTs). In the present work, several different water extracts, high in HTs, obtained from plants such as chestnut (Castanea sativa Mill.), myrtle (Myrtus communis L.) and pomegranate (Punica granatum L.), have been analysed and characterized by HPLC/DAD and HPLC/MS methods. Chestnut whole water extract (13% HTs) was investigated in agriculture as a natural soil acidifier, salinity control agent, phosphate solubilizer, iron complexing agent, and nemastat product. Aqueous extracts of the three plant species were also fractionated using both resins and membranes to recover purified molecules as bio-phenols for testing their antimicrobial activity. Novel HTs extracts exhibited antioxidant and antimicrobial activities, potentially prospecting they could support or even substitute molecules of current clinical use.
Hydrolyzable tannins from different plant species: their potential uses in agriculture and biomedical sciences
MIELE, SERGIO;
2011-01-01
Abstract
Tannins are distributed in several plant species, organs and tissues, where they play a role in inhibiting microbial decay, thus enhancing material durability. In the hydrolysable tannins (HTs), a carbohydrate molecule (usually D-glucose) is partially or totally esterified with phenolic groups , such as gallic or ellagic acids (gallotannins, GTs; or ellagitannins, ETs). HTs are hydrolyzed by weak acids or bases, and are more easily oxidized than condensed tannins (CTs). In the present work, several different water extracts, high in HTs, obtained from plants such as chestnut (Castanea sativa Mill.), myrtle (Myrtus communis L.) and pomegranate (Punica granatum L.), have been analysed and characterized by HPLC/DAD and HPLC/MS methods. Chestnut whole water extract (13% HTs) was investigated in agriculture as a natural soil acidifier, salinity control agent, phosphate solubilizer, iron complexing agent, and nemastat product. Aqueous extracts of the three plant species were also fractionated using both resins and membranes to recover purified molecules as bio-phenols for testing their antimicrobial activity. Novel HTs extracts exhibited antioxidant and antimicrobial activities, potentially prospecting they could support or even substitute molecules of current clinical use.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
