**1. Introduction**

The genus *Sarcococca* (Buxaceae) includes about 20 species, eight of which are found in China [1]. Some of them are used in TCM and traditional folk medicine to treat stomach pain, rheumatism, swollen sore throat, and bruises [2–4]. Previous studies on this genus revealed that the steroidal alkaloids were the main chemical components, and possessed a range of bioactivities (e.g., cholinesterase inhibiting, antitumor, antibacterial, antiulcer, antiplasmodial, and antidiabetic) [5–20]. For the search of bioactive metabolites from this genus, our previous investigation on S*arcococca ruscifolia* resulted in the discovery of two new steroidal alkaloids [16]. As part of our continuous exploration of active alkaloids, three new steroidal alkaloids, namely sarchookloides A–C (**1**–**3**) along with four known compounds, pachysamine G (**4**), pachysamine H (**5**), sarcovagine B (**6**), and pachyaximine A (**7**) (Figure 1), were isolated from the roots of *Sarcococca hookeriana*. The new compounds, sarchookloides A–C (**1**–**3**), were shown to possess a 3*α* substituent, which has rarely been reported [17]. The cytotoxicity assay on human cancer cell lines Hela, A549, MCF-7, SW480, and CEM in vitro demonstrated that these steroidal alkaloids exhibited potent antitumor activities. This paper describes the isolation, structure elucidation, and cytotoxicity activities of the isolates.
