Study On Extraction Of Arginine From The Pyracantha

Pyracantha is an evergreen rosaceous frutex and plentiful in our country. The red fruits from Pyracantha not only contain red pigment, protein, vitamin, calcium, phosphorus, iron, prandial fibrin, but also contain the special component called"Ju Tai"which is a kind of L-arginine that can accelerate secretion of the sex hormone. L-arginine is a kind of the half- necessary amino acid and can be greatly applied in medicine and food industry. So it has important value and wide foreground that exploit extraction and purification of L-arginine in Pyracantha.The extraction and purification of L-arginine from the natural wild Pyracantha were made by experiments. Some results were obtained as follows.1. The decoloration of the natural wild Pyracantha was studied by using the active carbon and No.711 anion resin, respectively. The results showed that the active carbon can adsorb L-arginine, but No.711 anion resin can adsorb lots of pigment and can't adsorb L-arginine, when the pH value of the solution is less than the isoelectric point of L-arginine. So No.711 anion resin was suggested to be used for decoloration.2. The extraction of L-arginine from the natural wild Pyracantha was investigated by using the phenyl formaldehyde deposition method and the ion exchange method, respectively. The results indicated that the appropriate pH for deposition is about 11, and the mol ratio between phenyl formaldehyde and L-arginine is about 2:1. However, the initial concentration of L-arginine must be higher than 20g/L when using the phenyl formaldehyde deposition method. The adsorption isotherm curves of L-arginine at room temperature were secondly measured by using No.732 cation resin and No. D001 macropore cation resin, respectively. The results showed that the equilibrium time are 4 hours for No.732 resin, and 30 minutes for No. D001resin, respectively, and the maximum amount of adsorption are 116.07 mg/g and 136.45 mg/g, respectively. So No.D001 resin was chosen as the ion exchanger. The effects of pH value and temperature on L-arginine adsorption by No.D001 cation resin were also investigated. The results indicated that the optimum pH value is between 7and 8, and the adsorption process can be carried out at room temperature. The studies of absorption way and the choice of scrub solution were carried out. The results indicated that the recovery rate can reach 95.8% under static adsorption condition, and the elution rate could reach 99% by using 3mol/L NH3·H2O. So the phenyl formaldehyde deposition wasn't adapt to extract L-arginine from Pyracantha directly and the ion exchange method was selected in this work.3. The raw production of L-arginine extracted was refined with method of the phenyl formaldehyde deposition and the ion exchange, respectively. The results showed that the recovery rate of L-arginine can reach 85% and 95.8% and the purity of L-arginine refined reached 95% and 92% for the deposition method and the ion exchange method, respectively. Compared to the deposition method, the ion exchange method is better for the refinement of raw L-arginine.4. The qualitative analysis was carried out with Sakaguchi reaction, paper chromatography and ultraviolet spectrophotometry, respectively. Infrared spectrometry was used as structure analysis of the production refined. Compared to the standard sample, the results showed the production is actually L-arginine in this work. Specific rotatory power was determined to be (+) 26.3.