| Oxytropis and Astragalu.s species known as Locoweeds are responsible for Locoism and other problems. Locoweeds in china are mainly distributed on the vast rangeland, exceeding 4 million hectares, in northwest, north and southwest China. Locoweeds contain the indolizidine alkaloid, swainsonine (SW). which has most serious toxicity, resulting neurological damage. abortion. fetal abnormality and male infertility. Besides containing toxin, Locoweeds are excellent herbage for animals. However, there is not the effective method to control Locoism. Locoism has become an important disease on the vast rangeland. In this paper. Attempt to protectively immunize animals against Locoism with SW-BSA was fulfilled. The results are as follows. I The isolation and identification of swainsonine from O.kansuensis Bunge The raw material for synthesis of SW-BSA was supplied by this test. O.kansuensis Bunge powder was dipped in methanol. The residue following evaporated of the methanol was dissolved in I N4 HCI and applied to a strong cation-exchange resin and eluted with I M NH4OH. The eluted solution was collected and concentrated to afford the crude alkaloid. Further isolation was conducted by two ways. One was extracting the crude alkaloid with ammoniated chloroform, applied the residue to a silica gel column, Eluted with chloroform: methanol: ammonia: water (70:26:2:2,V/V), each lOmL to collect, monitored by TLC and the activity of a -mannosidase, incorporated and evaporated the same fraction. The other was preparation by HPLC, using reverse phase (C-I 8 silica) and water/methanol, starting at 5% methanol and a linear gradient to 100% in 25 minutes. TLC plates sprayed with Ehrlich's reagent showed three single fraction, 65 -79 tube (H)and 106 120 (III) tube became visible as pink spots, Rr value were 0.44 and 0.12 respectively, fraction II was the sante as standard sample. 25 3 tube (I) became visible as purple spots, R value was 0.60. fraction I and II retained strong a -mannosidase inhibiting activity, III inhibiting effect was poor. Sublimed II under vacuum (-0.094pa) at 90t to obtain 70mg crystal of white needles, the yield of approximately 0.0014% based on dry plant weight. 1.04mg crystal was obtained by HPLC too, but the yield was 0.0052%. The crystal was swainsonine identified by TLC, MP, IR and MS. 2 Extraction of alkaloid from Rliizoctonia leguminicola and determination of swainsonine concentration Cultured the strains of 7-1, 7-3 and 3-1 R. leguminicola on the medium of PAD, bean sprout juice-sugar-agar, clover juice-sugar-agar. Strains 7-I and 7-3 were reviviscent and cultured on Czapek's medium at 25-27XD for 14d. The mold mycelium yield of strain 7-3 is more than 7-1. Collected mycelium, air dried, and extracted with ethanol (Soxhlet, 24hr) .The extract was concentrated to a syrup, shaken ( 3X ) with H20 CH2CI, (V/V) ,the water extract was brought to pHIO and again extracted ( 3X ) with H.,O CH.,Cl, ( V/V). The water layer was brought to pH7 and absorbed (30 mm) on a strong cation-exchange resin (H), eluted with I M NH4OH, and the filtrate was dried. The residue was brought pH7 and lyophilized to obtain a light brown powder. After dissolved 100 t g standard sample and 10mg powder in lmL pyridine, 0.ImL of the pyridine was applied to GC. The powder contains swainsonine, for the peak of the powder is consistent with the standard sample at the same GC condition. The peak of strain 7-I was 116.75mm(n10), strain 7-3 was 138.56mm(n10), the standard sample was I97.78mm(nI0) The concentration of swainsonine in powder of 7-1 and 7-3 were 5.9O3mgI...
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