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本文报导,从萝藦科牛弥菜属植物Marsdeniarostrata R.Br.中曾分离得两种生物碱即rostratine和dihydrorostratine。将总生物碱用硅胶GF254加25%AgNO_3制成制备性薄层板,以氯仿-甲醇(9∶1)展开,在Rf=0.40处分离得一个新生物碱rostratamine。从甲醇和乙醚得无色针晶,熔点277～279°,〔α〕_D~(22)-32±1(甲醇),分子式C_(27)H_(35)NO_7,经质谱m/e486及核磁共振等方法鉴定,rostratamine为一多羟基娠烷的烟碱酸酯: 在5%KOH的甲醇溶液中回流3小时,可得水解产物deacetylmetaplexiganin,熔点218～222°,
In this paper, two alkaloids, rostratine and dihydrorostratine, were isolated from Marsdeniarostrata R. Br. The total alkaloids were prepared on silica gel GF254 plus 25% AgNO_3 and developed with chloroform-methanol (9: 1) to separate a new alkaloid rostratamine at Rf = 0.40. From colorless crystals of methanol and ether, the melting point of 277 ~ 279 °, [α] _D ~ (22) -32 ± 1 (methanol), the molecular formula C 27 H 35 NO 7, the mass spectrum m / e 486 and nuclear magnetic Resonance and other methods identified rostratamine polyhydroxy-pregnane nicotinic acid ester: 5% KOH in methanol refluxed for 3 hours, the hydrolysis product deacetylmetaplexiganin, melting point 218 ~ 222 °,