Table 1 Inhibitory activity of the studied indirubin analogues against L. donovani promastigotes and intracellular amastigotes

1

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

-

2

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

-

3

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

-

4

NO

H

Br

H

H

H

1.15 ± 0.06

-

1.5 ± 0.07

5

NO

H

Br

H

H

H

0.9 ± 0.11

-

1.5 ± 0.08

6

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

-

7

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

> 10

8

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

>10

9

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

>10

10

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

> 10

11

NO

H

Br

H

H

H

0.75 ± 0.05

0.59 ± 0.07

6.25 ± 0.08

12

NO

H

Br

H

H

H

0.65 ± 0.09

0.80 ± 0.12

2.60 ± 0.05

13

NO

H

Br

H

H

H

0.82 ± 0.21

0.85 ± 0.16

2.41 ± 0.11

14

NO

H

Br

H

H

H

1.40 ± 0.10

1.71 ± 0.09

9.20 ± 0.15

15

NO

H

Br

H

H

H

1.50 ± 0.14

2.44 ± 0.17

6.00 ± 0.08

16

NO

H

Br

H

H

H

0.76 ± 0.03

1.54 ± 0.11

5.93 ± 0.04

17

NO

H

Br

H

H

H

0.76 ± 0.04

1.22 ± 0.06

10.00 ± 0.02

18

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

-

19

NO

H

Br

H

H

H

>3 μΜ

>3 μΜ

-

20

O

H

H

Br

H

H

-

>3 μΜ

>3 μΜ

-

21

NO

H

H

Br

H

H

H

>3 μΜ

>3 μΜ

> 10

22

O

H

H

Br

COOH

H

-

>3 μΜ

>3 μΜ

-

23

NO

H

H

Br

COOH

H

H

>3 μΜ

>3 μΜ

-

24

O

H

H

Br

H

COOH

-

>3 μΜ

>3 μΜ

-

25

NO

H

H

Br

H

COOMe

H

>3 μΜ

>3 μΜ

-

26

NO

H

H

Br

H

COOH

H

>3 μΜ

>3 μΜ

-

27

NO

H

H

CF₃

H

H

H

>3 μΜ

>3 μΜ

-

28

NO

H

H

CF₃

COOMe

H

H

>3 μΜ

>3 μΜ

-

29

O

H

H

CF₃

COOH

H

-

>3 μΜ

>3 μΜ

-

30

NO

H

H

CF₃

COOH

H

H

>3 μΜ

>3 μΜ

-

31

O

H

H

CF₃

H

COOH

-

>3 μΜ

>3 μΜ

-

32

NO

H

H

CF₃

H

COOMe

H

>3 μΜ

>3 μΜ

> 10

33

NO

H

H

CF₃

H

COOH

H

>3 μΜ

>3 μΜ

-

34

O

H

H

CF₃

H

-

>3 μΜ

>3 μΜ

-

35

NO

H

H

CF₃

H

H

>3 μΜ

>3 μΜ

-

6BIO

NO

H

Br

H

H

H

H

0.85 ± 0.05

0.70 ± 0.10

>25

5-Me-6-BIO

NO

CH₃

Br

H

H

H

H

1.2 ± 0.2

1.0 ± 0.1

>25

Amphotericin B

-

-

-

-

-

-

-

0.10 ± 0.01

0.20 ± 0.02

-