喜树叶主要有毒成分及其对奶山羊毒性的研究

Research on Main Toxic Components of the Leaves of Camototheca acuminata and Its Toxicity to Milk Goats

从喜树叶中分离出一种淡黄色针状结晶,含量约为0.01％,熔点为264～267℃。经TLC,IR,NMR,MS分析证实为喜树碱(camptothecin),毒性试验证明是喜树叶的主要有毒成分。给奶山羊灌服喜树叶(干粉)10g/kg或喜树叶粗提物0.16g/kg体重,每天一次连续3d可引起与自然发病症状相同的急性中毒。主要症状有出血性腹泻、脱水、肌肉震颤、昏迷和死亡;主要病理学变化为WBC减少,PCV升高,出现血尿、蛋白尿、糖尿和尿pH降低。浓缩尿中可检出喜树碱。病理学变化有胃、肠、肝、肾、淋巴结、脊髓充血、出血、变性和坏死。

A kind of light yellow needles shaped crystal has been isolated from the leaves of Camptotheca acuminata. The amount of the extracted product was about 0.01%, and its melting point was 264-267. The analysis by using TLC, IR, NMR, MS proved that it is alkaloid (.Camptothecin ). The toxicity test proved that Camptothecin is the main toxic element in the leaves of Camptotheca acuminata. Acute poisoning in milk goats induced by administrating the leaves of 10g/kg (D. W.) or its crude extract of 0.16/kg per day for 3 days showed similar sings as natural poisoning. The primary clinical signs included hemorrhagic diarrhea, dehydration, muscle tremor, coma and death. Main histopathologic losions showed congestion,hemorrhage, metaplasia and necrosis in most of organs such as gastrointestinal tract, kidney, liver, lymph, and spinal cord.Clinical pathologic examination showed leukopenia, high PCV, hemoturia,low urinary pH, proteinuria,and glycosuria, At the same time Cymptothecin can be determined in concentrated urine.