Studies On The Technique Of Extract And Purification And Its Anti-oxidant Ability Of Tannin From Nodes Of Lotus Root

Lotus roots has enormous consuming market in China, accompanying with huge amount of waste from lotus roots. The waste from lotus roots have the potential of processing value. Node of lotus have this kind of characteristic, it contained many bioactivity substance, such as tannin. tannin has been widely reported as a kind of polyphenol, secondary metabolized product, widely distributed in the plant kingdom. And it has many bio-function such as chelating with metal ion, precipitating with protein, anti-oxidant activity and blood-clotting etc. and this research Focused on the primary study of extracting, separating, purifying and identifying its structure and component. here are main research results:1) Gained the best extracting processing with ethanol solvent, through repeated trials and the mathematical model established: 7 times of 60% ethanol added to fresh node powder, then utilized the HCL to adjust the pH to 3, under the temperature of 20℃for 6h. The extract ratio was 0.09%.2) Purified the tannin from node of lotus roots with the macroporous resin, and then collect all the elution solvent, lyophilized the sample. After those process, the material treated with methanol, chloroform and lyophilized it again. The percentage of the tannin in the sample has been significantly risen up to 85%.3) Analyzed the tannin sample main component with RE-HPLC, the trials can research the conclusion that hydrolysable tannin contained gallic acid and ellagic acid. The infrared scanning trials demonstrated that the hydrolysable tannin, from node of lotus roots, contained the structure of hydroxyl and phenyl ring. All this can showed that tannin main structure comprised of unit of hydroxyl phenyl ring. UV scanning showed that hydrolysable tannin had the characteristic absorption peak at the wavelength of between 205-224nm and 261 -295nm.4) Chemical mimic system showed crude sample and purified sample had the potential of anti-oxidant ability. In vitro anti-oxidant experimental illustrated that crude sample and purified sample can inhibit the cell haemolyzed by itself and induced by H₂O₂ in some extend and reduced the mice liver's MDA content, and the MDA induced, and inhibit the swell of the mitochondrion in the liver.5) The vivo experiment showed that crude tannin sample and purified tannin sample can reduce the amount of MDA, enhancing the SOD activity due to improve the activity of SOD, scavenging the H₂O₂ and organic hydrogen peroxide. In other aspect hydrolysable tannin can regenerate the ability of V_E. both crude tannin sample and purified sample had the potential of anti-oxidant and deoxidized ability, and enhanced the bio-activity of anti-oxidant enzyme.