alkaloid of tobacco

例句：

1. 1.The alkaloid in tobacco is believed to have medicinal properties.
   烟草中的生物碱被认为具有药用性质。
2. 2.Tobacco use is associated with increased risk of heart disease and lung cancer.
   吸烟与心脏病和肺癌的风险增加有关。
3. 3. The alkaloid in tobacco has been used for centuries as a folk remedy.
   烟草中的生物碱自古以来就被用作民间疗法。