Table 1 In vitro cytotoxic activity of starting material compounds and indirubin-3′-oxime derivatives 6a–p. Indirubin-3′-oxime (compound 2) and Ellipticine was used as positive control.

1

1

 > 20

 > 20

 > 20

 > 20

 > 20

2

3

 > 20

 > 20

 > 20

 > 20

 > 20

3

4

 > 20

19.55 ± 1.23

18.59 ± 0.91

15.27 ± 0.35

16.22 ± 0.33

4

2

16.00 ± 0.62

16.36 ± 1.05

15.65 ± 0.74

16.50 ± 0.94

14.16 ± 0.71

5

6a

3.56 ± 0.75

2.26 ± 0.32

3.36 ± 0.64

2.39 ± 0.46

3.21 ± 0.43

6

6b

 > 20

 > 20

 > 20

 > 20

 > 20

7

6c

3.38 ± 0.68

2.99 ± 0.55

3.8 ± 0.52

1.43 ± 0.22

1.19 ± 0.12

8

6d

3.76 ± 0.75

2.85 ± 0.74

4.46 ± 1.18

3.40 ± 0.76

2.01 ± 0.64

9

6e

4.62 ± 1.07

3.28 ± 0.48

4.66 ± 0.92

3.27 ± 0.37

6.98 ± 0.25

10

6f

2.01 ± 0.43

1.30 ± 0.14

2.54 ± 0.25

0.98 ± 0.12

1.03 ± 0.11

11

6g

5.68 ± 0.71

3.96 ± 0.62

4.10 ± 0.57

4.82 ± 0.46

1.80 ± 0.21

12

6h

14.23 ± 1.79

8.74 ± 0.55

14.13 ± 1.18

6.50 ± 0.98

9.74 ± 0.53

13

6i

2.28 ± 0.12

2.07 ± 0.26

3.43 ± 0.84

1.28 ± 0.34

0.85 ± 0.05

14

6k

2.95 ± 0.19

2.50 ± 0.34

2.91 ± 0.13

1.29 ± 0.14

1.92 ± 0.17

15

6l

3.28 ± 0.25

2.07 ± 0.31

3.03 ± 0.11

1.28 ± 0.16

7.12 ± 0.18

16

6m

15.31 ± 0.17

8.74 ± 1.06

14.36 ± 0.72

15.96 ± 0.38

11.93 ± 1.75

17

6n

11.70 ± 0.23

10.08 ± 0.44

12.54 ± 0.53

10.44 ± 0.84

9.52 ± 0.07

18

6o

11.68 ± 0.26

8.80 ± 0.38

11.16 ± 0.76

9.39 ± 0.45

5.89 ± 0.75

19

6p

10.61 ± 0.79

8.61 ± 0.57

11.71 ± 0.48

11.25 ± 1.04

7.72 ± 0.42

20

Ellipticine

1.93 ± 0.54

2.50 ± 0.82

1.76 ± 0.63

2.19 ± 1.12

0.32 ± 0.03