New cytotoxic indole-type alkaloids obtained from Rhazya stricta leaves

Seven alkaloids of indole nucleus were isolated from Rhazya stricta (Apocynaceae). Two of which are new epi-rhazyaminine (1) and 20-epi-sitsirikine (2), while the rest are known; eburenine (3), strictamine (4), (16 R)-E-isositsirikine (5), antirhine (6), and strictanol (7). The chemical structures of the isolated compounds were elucidated by interpretation of the obtained spectral data 1D (¹H, ¹³C and DEPT) and 2D (COSY, HSQC, HMBC and NOESY) NMR, UV, IR and MS. Compounds 1-7 were tested against three cancer cell lines; human colorectal carcinoma (HCT-116), prostate cancer (PC-3), human hepatocellular liver carcinoma (HepG2) and normal adult African green monkey kidney (VERO).