2D NMR Spectroscopic Studies of the Toxic Alkaloid from Oxytropis Glabra D C.

The Oxytropis, legume genus, is native in the northwest of China, and some of its members have been reported to be toxic to grazing livestock. In the course of studying toxic reason of this legume, a toxic alkaloid was isolated from Oxytropis glabra D C. grown in the Inner Mongolian Autonomous Region. The LD+（50） of （—）-thermopsine（Ⅰ） was shown to be 89.98 mg/kg（in mice）. This paper reports an approach to the structure elucidation of（-）-thermopsine by combining 2D NMR[;H-;H and;H-;C （one-bond and long-range） COSY] and other physicochemical methods. The stereochemistry of compound Ⅰ is also discussed.

Preparation of Polyclonal Antibody Against Swainsonine and Its Effects in Treatment of Oxytropis glabrapoisoned Rabbits

This study was conducted to optimize immunization program to gain the serum against swainsonine （SW） with high titer and to analyze the effects of polychinal antibody in treatment of loco disease of rabbits. Eighteen rabbits were randomly separated into control group, poisoning group and curing group, with six rabbits in each group. Rabbits in poisoning group and curing group were fed 10 g/（kg ~ d） powder of Oxytropis glabra DC every morning for 70 d till the rabbits in poisoning group began to die. From the 21＇t to 24＇h d of O. glabra administration, each of the rabbits in curing group was injected with 1 mL of polyclonal anti- body against SW every day. Blood samples were collected before O. glabra challenge, and then once every 7 d for the serological and immunological evaluation of serum. The resuhs showed that the serum alkaline phosphatase （AKP） activity and SW content in poisoning groups were significantly higher than those in control group on the 7th d （P 〈0.05 ） ; the serum aspartate transaminase （AST） and lactate dehydrogenase （LDH） activity in poisoning groups were significantly higher than those in control group on the 14th d （P 〈 0.05 ）, while the serum ct - mannosidase （AMA） and rate of E-rosette formation in poisoning groups were signifi- cantly lower than those in control group （ P 〈 0.05 ） ; the serum blood urea nitrogen （BUN）, creatinine （ CRE ） and glucose （ GLU ） concentration in poisoning groups were significantly higher than those in control group on the 21＇t d （P 〈 0.05 ）. By injecting serum against swainsonine, the serum AKP, LDH, AST, alanine transaminase （ALT） activity and contents of BUN, CRE, GLU, SW were reduced and serum AMA and rate of E-rosette formation were increased in curing group, by comparing with those in poisoning group. These results in this experiment indicated that polyclonal antibody against SW had good value of preventing from O. glabra DC.

In Vitro Antioxidative Activities of Flavonoid from Oxytropis glabra DC

Anti-lipid peroxidation activity, reducing power and chelating power of flavonoid extracts from Oxytropis glabra DC, as well as their elimination effect on DPPH, superoxide anion and hydroxyl radicals were determined in the paper, so as to evaluate in vitro antioxidative activities of flavonoid extracted from O. glabra. The results showed that flavonoid from O. glabra had fairly strong anti-lipid peroxidation. The antioxidation effects on rapeseed oil successively were vitamin C 〉 sample 〉 vitamin E 〉 BHT 〉 CK; the effects on cottonseed oil successively were sample 〉 vitamin C 〉 BHT 〉 vitamin E 〉 CK; the effects on sunflower oil successively were sample 〉 vitamin C 〉 vitamin E 〉 BHT 〉 CK; the effects on lard successively were BHT 〉 vitamin C 〉 sample 〉 vitamin E 〉 CK. The samples had stronger clearance rate against DPPH, superoxide anion and hydroxyl radicals than control; the reducing power of sample was weaker than Vitamin C and stronger than Vitamin E ; chelating power of sample was weaker than EDTA. Flavonoid from O. glabra had the value for further development and utilization as natural antioxidant.

Effect of Oxytropis glabra DC. Poisoning on α-Mannosidase(AMA) Expression in Mice Brain Tissue

The effect of Oxytropis glabra DC. on α-mannosidase( AMA) expression in mice brain tissue was explored to reveal the toxicity mechanism of O. glabra. Forty mice were randomly divided into four groups,namely control group,experimental group I,experimental group II and experimental group III. The mice in three experimental groups were fed with O. glabra at the doses of 1,5 and 10 g per kilogram weight,respectively. After challenge for 63 d,mice brains were collected to detect changes in distribution and expression of AMA in different brain regions. The results showed that O. glabra poisoning led to declined AMA mRNA expression in mice brain tissue,but the mice in experimental group I had no significant difference with those in control group( P > 0. 05). The AMA mRNA expression in cerebellum,cerebrum and thalamus of mice in experimental groups II and III were significantly lower than that in control group( P < 0. 05),but the AMA mRNA expression in hippocampus and brainstem in three experimental groups had no significant difference with that in control group( P > 0. 05). AMA had very weak expression in hippocampus and brainstem,but it had expressions in other regions,and the expression was positively correlated with the number of neurons and granulosa cells. The results showed that different doses of O. glabra reduced AMA mRNA expression in mice brain tissue,while cerebellum,cerebrum and thalamus were the main target function areas.