Novel indole C-glycosides from Isatis indigotica and their potential cytotoxic activity

Two novel indole C-glycosides, which were the first reported alkaloids C-glycosides from Isatis indigotica, together with five known alkaloids were isolated. The novel alkaloids were elucidated to be indole-3-acetonitrile-4-methoxy-2-C-beta-D-glucopyranoside (1) and N-methoxy-indole-3-acetonitrile-2-C-beta-D-glucopyranoside (2) on the basis of spectroscopic analysis. 1 exhibited significant cytotoxic activities against human myeloid leukemia HL-60 and human liver cancer HepG2 cells with the IC50 of 1.3 +/- 0.1 and 2.1 +/- 0.3 mu M, respectively. 2 showed potential cytotoxic activities against HL-60 and human myeloid leukemia Mata cells with the IC50 of 5.1 +/- 0.4 and 12.1 +/- 0.8 mu M, respectively. (C) 2010 Elsevier B.V. All rights reserved.