Shahin Hassanpour1*, Naser Maheri-Sis1, Behrad Eshratkhah2 and Farhad Baghbani Mehmandar3
- Department of Animal Science, Shabestar Branch, Islamic Azad University, Shabestar, Iran.
- Department of Veterinary Medicine, Shabestar Branch, Islamic Azad University, Shabestar, Iran.
- Department of Agriculture, Payame Noor University, PO BOX 19395-3697 Tehran, Iran.
Abstract: The objective of this review was to investigate and identification of structure and role of the tannins in plants. During growth and maturation period in plants, some substances can be found in structure of them which they have essential role in plant fortune. These substances are called plants secondary metabolites. One of the most important of secondary metabolites is Tannins. The function of tannins in plants is a much discussed by previous researchers issue. A great deal of research with tannins has followed an approach that looks at biological relationships: taxonomy, phylogeny, biosynthesis, nutritional and physiological effects on herbivorous animals e.g. ruminants. Tannins are defined as phenolic compounds of high molecular weight ranging from 500 to more than 3000 which they found in plants leaves, bark, wood and bound to proteins that form insoluble or soluble tannin-protein complexes. They have been closely associated with plant defense mechanisms towards mammalian herbivores and insect. Tannins are divided into two main groups, according to their chemical structure and properties: hydrolysable (HT) and condensed tannins (CT). Hydrolysable tannins are usually found in lower concentrations in plants than CTs. Condensed tannins consist of flavanoid units (flavan-3-ol) linked by carbon-carbon bonds. They are found in many plant species such as Acacia spp, Sericea lespedeza as well as pasture species such as Lotus spp. In recent years many researchers demonstrated that tannins have positive effects on animals by anti microbial, anthelmintic, protein bypassed effects in ruminants.
Keywords: plants secondary metabolites, Tannins, Hydrolysable tannins, Condensed tannins.
Int. J. Forest, Soil and Erosion, 2011 1 (1):47-53