Extraction Process And The Properties Of The Larch Arabinogalatan

The North China larch was used as the raw material to extract larch arabinogalactan by flash-extraction, assisted with the traditional warm water extraction of larch arabinogalactan, based on four single factor experiments, the extraction condition was optimized by the Response Surface Analysis. Then repeatedly alcoholsinking method was carried on the preliminary purification, and its structure characteristics were researched, as well as to study its antioxidant activity and immune activity. The results of the study were as follows:1.Through the single factor experiment and the design principle of responses surface experimental, the optimization technology of flash-extraction of larch arabinogalactan was obtained. During the experiment, the yield of arabinogalactan wasthe index, the effects of extraction time, material liquid ratio, extraction temperature and extraction time on the yield were studied. On the basis of single factor experiments, according to the design principle of the Box-Behnken center combination experiments, Taking the extraction time, material liquid ratio, extraction time and flash time as the independent variables, the yield of arabinogalactan was the response value, the extraction conditions were optimized by the response surface analysis method with four factors and three levels. The results showed that the optimal conditions of extraction of the larch arabinogalactan from the North China larch were as follows:extraction temperature,70℃. flash-extraction time,1.6 min. solid -to- liquid (g/mL) ratio, 1:16and extraction time,22 min. Under this condition, the maximal content of larch arabinogalactan was up to 14.30±0.05%.2.The analysis of high performance liquid chromatography(HPLC) showed that, after purified by repeated ethanol precipitation, the extract of arabinogalactan in larch was improved by 3.83%, the content of arabinogalactan in the sample was 86.39% in Arabia. The molar ratio of galactose to arabia in arabinogalactan was 8.086:1. By using scanning electron microscopy (SEM) analysis of the arabinogalactan samples, found that the distribution of it was the irregular geometry, the surface was smooth, the details were not clear enough. and the infrared spectrum (IR) analysis showed that it contained a typical groups of saccharide compounds, also its trend was consistent with the standards. And according to the fingerprint area absorption peak to do qualitative analysis, the sample in the fingerprint area characteristic absorption frequency and the standard product was consistent. X-ray diffraction (XRD) pattern showed that the crystallinity of arabinogalactan was low (32.2%), and the molecular rigidity is not strong. The X-ray diffraction analysis of the samples and standards of arabinogalactan was showed that the crystallinity of the samples and the standards of arabinogalactan were 32.2% and 25.8%, the two were basically consistent. Thermo gravimetric analysis (TGA) showed that the weight loss of the samples in arabinogalactan appeared at the temperature of 284.74℃, while the standards weight loss peak appeared at the temperature of 310.19℃, speculate on the possible reasons for samples containing impurities that lead to the pyrolysis temperature produced certain deviation with standards and the peak shape was more blunt. Generally speaking, the weight loss curve of the sample was consistent with the standards. Based on the above results, the polysaccharide can be characterized as arabinogalactan.3.The antioxidant activity showed that arabinogalactan had antioxidant activity, but the antioxidant activity was less than that of VC.4.The experimental results showed that the Larch arabinogalactan had certain immune regulation effect, and the effect was best in the lmg/mL dosage.