| Lycoris radiate is a novel starch resources that contains various pharmacologically active substances of high value-added, such as alkaloids, polysaccharide.These ingredients will exert its pharmacology function in medicine, health care and other fields. In this paper, on the basis of using its producing ethanol, in order to make full use of raw material, we conducted further studies with physiologically active substances in its bulbs.The paper studied the L. radiate alkaloids first. Based on the inhibition effect on Saccharomyces cereviviae growth and the notable medicinal value of L. radiate alkaloids, importance and necessity of alkaloids extraction before ethanol fermentation from L. radiate tuber was proposed. After that, the alkaloids extraction methods and conditions were discussed and the optimized was as following: methanol as extracting agent and the sample under solid to liquid ratio 1:15(w:v), pH 11.0, the mixture maintained in water bath constantly at 60oC for 1 h. Under that, alkaloids extraction ratio reaches to 28.70 milligram per gram over raw materials, Starch content of residue after extraction is 33.93% dry weight of raw materials, starch retention rate of 67.64%. Subsequently, ethanol fermentation processes from L. radiate raw materials with and without alkaloids were compared and the results showed that L. radiate alkaloids had both significantly inhibition on glucoamylase activity and the growth of S. cereviviae, however, nearly no effects onα-amylase activity. The current study initially reveals the inhibition mechanism in ethanol fermentation process by L. radiate alkaloids and will be helpful for integrated application of L. radiate in ethanol and alkaloids production.Then studied the coupling relationship of non-starch polysaccharides extraction and ethanol fermentation with the L. radiate raw material. Preliminary research data showed, however, non-starch polysaccharides extraction in addition to causing the loss of amylose, it doesn't affect the efficiency of ethanol fermentation. On the other hand, the ethanol fermentation process influence senior structure of polysaccharide, this effect will be lead polysaccharide to degradation.Compared with two polysaccharides which extracted before and after ethanol fermentation process, both in structure and composition are quite different.Two mainly parts are composed polysaccharide study, which are extraction and purification. Extraction has being used the traditional hot water extraction. Through the orthogonal experimental to obtain the optimal extraction conditions as following: the sample under solid to liquid ratio 1:20(w:v), the repeat this conditions to extracted 3 times. Under that, polysaccharide extraction ratio reaches to 56.55 milligram per gram over raw materials. Becouse of polysaccharide crude extract contains a lot of starch,α-amylase can be used to eliminate soluble starch interference before the purification. Processing conditions are: added enoughα-amylase into polysaccharide crude extract, and then made mixture maintained in water bath constantly at 74oC for 15 min. After that, the mixture followed by ethanol precipitation, removal of protein and pigment. The polysaccharide liquid, which were treatment with above steps, using Sephacryl S-100 HR gel filtration chromatography(GFC), differents of molecular weight polysaccharides was got. And then these different components'purifity and molecular weight were confirmed by HPLC. The results show two homogeneous polysaccharides(LPA-1 and LPA-2)were obtained, the molecular weight were 29.4 kDa and 23.0 kDa. One of the major components was LPA-1, which is a light gray solid, tasteless, soluble in water, but insoluble in ethanol, ethyl ether, acetone, chloroform or other organic solvents. Experiments show that this substance was the non-starch polysaccharides, which doesn't contain phenols, protein and uronic acid. IR spectra measurements showed its a pyran-type neutral polysaccharide withβ-glycosidic bond. The GC-MS analysis of LPA-1 is a heteropolysaccharide with 5 monosaccharide. The main monosaccharide composition were mannose, glucose and galactose, the molar ratio of 5 monosaccharides were 1: 0.65: 2.34: 5.84: 5.14. |
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