alkaloids

n.natural bases containing nitrogen found in plants

1. Alkaloids are often extracted from plants and used in medicine for their analgesic and stimulant properties.
   生物碱通常从植物中提取，并因其镇痛和兴奋作用而在医学中应用。
2. Some alkaloids, such as morphine and caffeine, have important medicinal uses, while others can be toxic.
   一些生物碱，如吗啡和咖啡因，具有重要的药用价值，而另一些则可能具有毒性。
3. The alkaloid quinine is used to treat malaria.
   生物碱奎宁用于治疗疟疾。
4. Nicotine, an alkaloid found in tobacco, is known for its addictive properties.
   烟草中的生物碱尼古丁以其成瘾性而著名。