Diacetylneriifolin的强心和镇静作用

从黄花夹竹桃种仁中分得的一种强心甙neriifolin,乙酰化后得diacetylneriifolin,后者对心脏的作用减弱,生物活性降低。neriifolin的鸽最小致死量为0.217士0.008毫克(标准誤)/公斤,而diacetylneriifolin为0.649±0.024毫克/公斤;并且显效速度比neriifolin更为迟慢,蓄积性也增大。此外,产生明显的鎮靜催眠作用,可拮抗咖啡因引起的小鼠兴奋活动,延长环己烯巴比妥鈉的睡眠时間和降低小鼠的体溫?曰ЫY构改变而引起的药理作用差异的原因作了初步探討。

THE CARDIAC AND SEDATIVE EFFECTS OF DIACETYLNERIIFOLIN

Neriifolin is a cardiac glycoside isolated from the kernels of Thevetia neriifolia Juss. Diacetylneriifolin was obtained by acetylation of neriifolin. The minimum lethal doses of neriifolin and diacetylneriifolin in pigeons were found to be 0.217±0.008 mg (s.e.)/kg and 0.649±0.024 mg/kg respectively. Therefore, the biological potency of neriifolin was reduced by diacetylation. Furthermore the onset of action of diacetylneriifolin became slower than neriifolin; and it possessed a greater cumulative action than neriifolin. In experiments in pigeons, diacetylneriifolin showed sedative effect in small doses, and induced hypnosis or anaesthesia in large doses, but neriifolin did not give any such effect. Diacetylneriifolin prolonged the hexobarbital-sleeping time and antagonised the excitatory action of caffeine in mice receving intraperitoneal does of 1.0mg/kg.Hence it was a depressant of central nervous system.