英语语法分析

Therefore, derivatives of camptothecin are becoming the focus of research.

因而喜树碱衍生物成为研究的热点。

Camptothecin and its derivatives are alkaloids possessing anti tumor activities.

喜树碱及其衍生物是一类具有抗癌活性的生物碱。

Objective: to explore the effect of hydroxy camptothecin on colorectal carcinoma cells in vitro.

目的探讨羟基喜树碱对肠癌细胞的体外作用。